Results

SYSTEMATICS

Superfamily Fissurelloidea Fleming, 1822

Family Fissurellidae Fleming, 1822

General remarks: Fissurellidae is a diverse family of small to large (2–125 mm) limpet-like marine snails with a global distribution. Species in this family typically inhabit hard substrates, living attached to rocks from the intertidal zone to deep-water environments (Farfante, Reference Farfante1943a). They are chiefly recognised by their limpet-like shells, which usually bear a conspicuous apical foramen, anterior slit, or notch used for waste elimination or gamete release (Aktipis et al., Reference Aktipis, Boehm and Giribet2011; Cunha et al., Reference Cunha, Lemer, Bouchet, Kano and Giribet2019). Fissurellids feed on a variety of materials and organisms, including detritus, algae, sponges, foraminiferans, and tunicates (Herbert, Reference Herbert1991; Williams et al., Reference Williams, Donald, Spencer and Nakano2010). Crown-group fissurellids are estimated to have originated around 175 Ma in the Tethys Sea, and the family has a particularly rich fossil record (Tracey et al., Reference Tracey, Todd, Erwin and Benton1993; Cunha et al., Reference Cunha, Lemer, Bouchet, Kano and Giribet2019). Although fissurellids have frequently been included in phylogenetic analyses of Vetigastropoda and related groups (e.g., Harasewych et al., Reference Harasewych, Adamkewicz, Blake, Saudek, Spriggs and Bult1997; Sasaki, Reference Sasaki1998; Geiger and Thacker, Reference Geiger and Thacker2005; Kano, Reference Kano2008; Williams et al., Reference Williams, Karube and Ozawa2008; Aktipis and Giribet, Reference Aktipis and Giribet2012; Uribe et al., Reference Uribe, Kano, Templado and Zardoya2015), studies focusing specifically on relationships within the family remained relatively scarce (e.g., McLean and Geiger, Reference McLean and Geiger1998; Aktipis et al., Reference Aktipis, Boehm and Giribet2011) until recently. A major advance was achieved by Cunha et al. (Reference Cunha, Lemer, Bouchet, Kano and Giribet2019), who presented a comprehensive phylogeny based on combined molecular and morphological data, leading to a reevaluation of several taxa. Currently, Fissurellidae comprises 49 genera and 500–600 species worldwide (Fleming, Reference Fleming2025), with 15 genera and 53 species recorded from Brazilian waters (Simone, Reference Simone2024a).

Genus Diodora Gray, 1821

Synonymy see McLean and Geiger (Reference McLean and Geiger1998: 10).

Type species: Patella apertura Montagu, 1803 (= Diodora graeca L.) by monotypy; Recent, Mediterranean.

Diodora fluviana (Dall, 1889)

(Figure 2A–C)

Figure 1.

Seamount chain off northeastern Brazil; red dot indicates the location of Canopus Bank. CE = Ceará, PB = Paraíba, PI = Piauí, RN = Rio Grande do Norte.

Figure 2.

Diodora fluviana: (A–C) MZSP 170741 from Canopus Bank: (A) apical view (L = 11.3 mm, W = 7.5 mm); (B) apertural view; (C) left lateral view (H = 4.9 mm). (D–H) Diodora listeri MZSP 170742 from Canopus Bank: (D) apical view (L = 5.8 mm, W = 4.1 mm); (E) apertural view; (F) left lateral view (H = 2.9 mm); (G–H) same, spm #2: (G) apical view (L = 3.2 mm, W = 2.0 mm); (H) right lateral view (H = 1.3 mm).

Synonymy see Métivier (Reference Métivier1972b). Complement:

Fissurella (Glyphis) fluviana Dall, Reference Dall1889: 408, pl. 14, figs. 6–6a.

Diodora fluviana: Métivier, Reference Métivier1972b: 412; Abbott, Reference Abbott1974: 24; Rios, Reference Rios1975: 15, pl. 2, fig. 18; Reference Rios1985: 13, pl. 7, fig. 47; Absalão, Reference Absalão1989: 2; Rios, Reference Rios1994: 25, pl. 6, fig. 52; Redfern, Reference Redfern2001: 5, pl. 3, fig. 18; García and Lee, Reference García and Lee2002: 11; Rios, Reference Rios2009: 31, fig. 61; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009: 619; Espinosa et al., Reference Espinosa, Ortea, Sanchez and Gutiérrez2012: 57.

Distribution: Previously known from North Carolina to Brazil (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009), from the states of Rio Grande do Norte to Bahia (Rios, Reference Rios1994); distribution in Brazil expanded herein north-westward to the state of Ceará.

Habitat: Benthos, on calcareous algae (Rios, Reference Rios1975), 38–1,472 m depths (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 170741, 8 sh + juveniles (viii/2005).

Measurements (in mm; n = 8): L = 8.6 ± 1.7, W = 5.7 ± 1.1, H = 3.7 ± 0.7.

Remarks: The shells recovered from the Canopus samples can be identified as D. fluviana, primarily based on their small size (L = ∼10 mm), sculpture pattern of prominent axial ribs intercalated with two to three smaller riblets, all crossed by concentric threads, ovate foramen (Figure 2A, B), and characteristic olive-green and white colouration (Figure 2A, C). Rios (Reference Rios1994) reported the occurrence of D. fluviana in northeastern Brazil, ranging from the states of Rio Grande do Norte to Bahia. The present specimens expand the known distribution ca. 300 km north-westward into waters of the neighbouring state of Ceará, from 5°S to 2°S. The bathymetric data are within the known range of the species (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009).

Diodora listeri (d’Orbigny, 1853)

(Figure 2D–H)

Synonymy see Farfante (Reference Farfante1943b). Complement:

Diodora listeri: Farfante, Reference Farfante1943b: 3, pl. 1, figs. 1–10; Abbott, Reference Abbott1954: 96, pl. 17, fig. L; Coomans, Reference Coomans1958: 52, pl. 3; Warmke and Abbott, Reference Warmke and Abbott1961: 37, pl. 5, fig. J; Rios, Reference Rios1970: 17; Abbott, Reference Abbott1974: 23, fig. 89; Rios, Reference Rios1975: 15, pl. 3, fig. 21; Oliveira et al., Reference Oliveira, Rezende and Castro1981: 36; Vokes and Vokes, Reference Vokes and Vokes1983: 11, 49, pl. 1, fig. 7; Rios, Reference Rios1985: 14, pl. 7, fig. 50; Robinson and Montoya, Reference Robinson and Montoya1987: 378; Jong and Coomans, Reference Jong and Coomans1988: 10, pl. 29, fig. 8; Díaz and Puyana, Reference Díaz and Puyana1994: 110, pl. 33, fig. 327; Rios, Reference Rios1994: 25, pl. 7, fig. 55; Lyons, Reference Lyons, Camp, Lyons and Perkins1998: 16; Redfern, Reference Redfern2001: 5, pl. 3, fig. 20; Leal, Reference Leal and Carpenter2002: 121, text fig.; Rios, Reference Rios2009: 32, fig. 64; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009: 619; Aktipis et al., Reference Aktipis, Boehm and Giribet2011: 243, fig. 1C; Petuch and Myers, Reference Petuch and Myers2014: 58, fig. 3.10B; Cruz-López et al., Reference Cruz-López, Villanueva-sousa, Vázquez-machorro, Tello-musi, Granados-barba, Ortiz-lozano, Salas-monreal and González-gándara2015: 81; Hewitt, Reference Hewitt2015: 41; Ortigosa et al., Reference Ortigosa, Suárez-Mozo, Barrera and Simões2018: 7, fig. 1(18); Cunha et al., Reference Cunha, Lemer, Bouchet, Kano and Giribet2019: 3, tab. 1; Calzadilla-Milian et al., Reference Calzadilla-Milian, Armiñana-garcía, Sarría-martínez, Fimia-duarte, Iannacone, Grandía-guzmán and Castillo-fleites2020: 297; Espinosa et al., Reference Espinosa, Ortea and Pina Amargós2022: 99, fig. 18A.

Distribution: Previously known from East Florida to Brazil (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009), from the state of Pernambuco to Bahia (Rios, Reference Rios1975, Reference Rios1994); distribution in Brazil expanded herein north-westward into the state of Ceará.

Habitat: Benthos, among intertidal rocks and coral (Rios, Reference Rios1975) in shallow waters to 500 m depths (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 170742, 2 sh (viii/2005).

Measurements (in mm): Largest specimen, L = 5.8, W = 4.1, H = 2.9.

Remarks: Although both shells recovered from the Canopus samples are juveniles, they can be confidently identified as D. listeri. The shells are elevated (Figure 2F, H), with sculpture consisting of rounded axial ribs of alternating sizes separated by deep interspaces, which are crossed by radial elements forming strong nodules at the intersections and dividing the interspaces into square pits (Figure 2D, G). The shell margin is distinctly crenulated (Figure 2E), and the outer (Figure 2D, F–H) and inner (Figure 2E) colouration falls within the range described by Farfante (Reference Farfante1943b). Rios (Reference Rios1975, Reference Rios1994) reported the occurrence of D. listeri in Brazil from the states of Pernambuco to Bahia. Our findings extend its known distribution ca. 750 km north-westward into the waters of Ceará from 7°30′S to 2°S, thereby bridging the gap between Bermuda, its southernmost record in the Caribbean (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009), and Pernambuco.

Diodora mirifica Métivier, 1972

(Figure 3)

Figure 3.

Diodora mirifica: (A–C) Holotype MNHN IM-2000-4962, from Fernando de Noronha: (A) apical view (L = 8.0 mm, W = 5.2 mm); (B) apertural view; (C) left lateral view (H = 3.4 mm). (D–F) Paratype MNHN IM-2000-4963 (L = 6.8 mm, W = 4.0 mm): (D) apical view; (E) apertural view; (F) left lateral view (H = 3.3 mm). (G–I) MZSP 131040 from Canopus Bank: (G) apical view (L = 9.63 mm, W = 5.99 mm); (H) apertural view; (I) left lateral view (H = 4.32 mm). (J–L) MZSP 131040 from Canopus Bank: (J) apical view (L = 6.95 mm, W = 4.26 mm); (K) apertural view; (L) left lateral view (H = 2.91 mm). Type photos are a courtesy of the MNHN.

Synonymy see Simone and Cunha (Reference Simone and Cunha2014). Complement:

Diodora mirifica Métivier, Reference Métivier1972a: 409, pl. I, figs. 1–10; Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009: 147; Simone and Cunha, Reference Simone and Cunha2014: 464, fig. 152.

Distribution: Brazil, from Maranhão to Espírito Santo states, including oceanic islands (Leal, Reference Leal1991).

Habitat: On corals and calcareous algae from 0 to 63 m depths (Rios, Reference Rios2009), up to 260 m (shells only; present study).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 131040, 26 sh (viii/2005), MZSP 170743, 8 sh (viii/2005). Additional material: Holotype MNHN IM-2000-4962, Brazil, Fernando de Noronha Island (1968). Paratypes: MNHN IM-2000-4963, Brazil, Ceará, off Fortaleza, R/V ‘Almirante Saldanha’ sta. 1701, 01°57′S, 37°46′W, 57 m, 2 sh (viii–xii/1967).

Measurements (in mm; n = 10): L = 7.56 ± 0.78, W = 4.48 ± 0.48, H = 3.4 ± 0.4.

Remarks: The colour pattern of radially arranged dark brown/black spots on a white background sets D. mirifica apart from every other local congener. Métivier (Reference Métivier1972b) mentioned two dark areas on each side of the foramen internally (Figure 3B, K), but in most specimens, these dark areas are connected, forming a contiguous semicircle (Figure 3H). This darkened area is a distinguishing character unrelated to any external colouration or marking. Most of the internal colouration stressed in the original description corresponds to the external pigmentation visible through transparency in young and worn-out specimens (Figure 3K). In the Canopus specimens, the darker areas are much less intense and spread apart than in the types from Fernando de Noronha, with some individuals being nearly white (Figure 3H–I).

This species was described from the Fernando de Noronha Archipelago but is also very common along a large portion of the north-northeastern Brazilian coast. It occurs in other oceanic islands and seamounts (Leal, Reference Leal1991), and except for the bathymetric range expansion (from 0–63 to 260 m) consisting of dead specimens studied herein, the records from Canopus are within the known distribution of thespecies.

Diodora sayi (Dall, 1889)

(Figure 4)

Figure 4.

Diodora sayi: (A–C) Lectotype MCZ 125767, from Cuba: (A) apical view (L = 8.0 mm, W = 5.2 mm); (B) apertural view; (C) left lateral view (H = 3.4 mm). (D) Paralectotype MCZ 7637, apical view (L = 6.8 mm, W = 4.0 mm). (E–H) MZSP 170744 from Canopus: (E) spm #1, apical view (L = 12.4 mm, W = 7.4 mm); (F) apertural view; (G) left lateral view (H = 4.8 mm); (H) spm #2, apical view (L = 16.2 mm, W = 10.4 mm). (I–L) MZSP 70292 from Canopus: (I) apical view (L = 9.18 mm, W = 5.35 mm); (J) apertural view; (K) left lateral view (H = 3.5 mm); (L) detail of inner side, showing the foramen (arrow indicates the location of the internal callus).

Synonymy see Métivier (Reference Métivier1972b) and Leal (Reference Leal1991). Complement:

Fissurella (Cremides) alternata var. sayi Dall Reference Dall1889: 407.

Diodora sayi: Rios, Reference Rios1970: 18; Métivier, Reference Métivier1972b: 409; Rios, Reference Rios1975: 16, pl. 3, fig. 25; Oliveira et al., Reference Oliveira, Rezende and Castro1981: 36; Rios, Reference Rios1985: 14, pl. 7, fig. 54; Jong and Coomans, Reference Jong and Coomans1988: 10; Absalão, Reference Absalão1989: 2; Leal, Reference Leal1991: 36; Díaz and Puyana, Reference Díaz and Puyana1994: 110, fig. 330; Rios, Reference Rios1994: 26, pl. 7, fig. 59; Macsotay and Campos, Reference Macsotay and Campos2001: 26; García and Lee, Reference García and Lee2002: 11; Gracia et al., Reference Gracia, Ardila and Díaz2004: 45; Cruz and Gándara, Reference Cruz and Gándara2006: 130; Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009: 147; Rios, Reference Rios2009: 33, fig. 68; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009: 619; Tunnell et al., Reference Tunnell, Andrews, Barrera and Moretzsohn2010: 107, text fig.; Daccarett and Bossio, Reference Daccarett and Bossio2011: 48, fig. 25; Villegas et al., Reference Villegas, Sánchez and Cabarcas2013: 8, tab. 4; Cruz-López et al., Reference Cruz-López, Villanueva-sousa, Vázquez-machorro, Tello-musi, Granados-barba, Ortiz-lozano, Salas-monreal and González-gándara2015: 81.

Diodora arcuata: Rios, Reference Rios2009: 30, text fig. [in part; non Sowerby, 1862].

Distribution: Southeast Florida to southeastern Brazil, including oceanic islands (Leal, Reference Leal1991).

Habitat: From 15 to 174 m (live specimens; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009), up to 1,472 m (empty shells, present study).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 60–70 m, MZSP 70292, 1 sh (viii/2005); 240–260 m, MZSP 170744, 8 sh (viii/2005). Additional material: Lectotype MCZ 125767, Cuba, off Havana, R/V Blake sta. 62, 146 m (1877–78); Paralectotypes: MCZ 7637, Cuba, off Morro Light, R/V Blake sta. 2, 23°14′N, 82°25′W, 1,472 m, 1 sh (1877); MCZ 7638, Mexico, Yucatan, Campeche Bank, R/V Blake sta. 32, 23°32′N, 88°5′W, 173 m, 1 sh (1877); USNM 95158, 9 sh, same data as lectotype; MCZ 7640, 5 sh, same data as lectotype; MCZ 7642, Cuba, Yucatan Strait, 1,170 m, 2 sh (1877).

Measurements (in mm; n = 4): L = 12.9 ± 2.9, W = 8.0 ± 2.0, H = 5.0 ± 1.2.

Remarks: Dall (Reference Dall1889) introduced the name sayi as a variation of Diodora alternata Say, 1822 (= D. cayenensis Lamarck, 1822), providing a brief description. Farfante (Reference Farfante1943b) recognised this so-called variation as a distinct species based on conchological dissimilarities such as a more anterior apex, sculpture consisting of even-sized ribs and the trilobated foramen (Figure 4A–D), as opposed to keyhole-shaped in D. cayenensis. Farfante (Reference Farfante1943b) also designated the lectotype (MCZ 125767, Figure 4A–C) even though Dall (Reference Dall1889) did not state the type locality.

Despite the vast variability of the species, no new synonyms were described, and the name remained stable with no new proposed combinations after Farfante’s (Reference Farfante1943b) revision. No formal diagnosis for D. sayi was ever given in the literature, but different authors mentioned the trilobate foramen as a strongly distinctive character (e.g., Farfante, Reference Farfante1943a; Leal, Reference Leal1991). This trilobate aspect stems from an asymmetrical internal thickening that produces a callus (Figure 4L). This feature sets D. sayi apart from virtually every other local congener in the southwestern Atlantic, which usually has a keyhole-shaped or ovate foramen. It can be verified in the present specimens, which also agree quite well with Farfante’s (Reference Farfante1943b) redescription in having an oblong-ovate base (Figure 4F, J), crenulated margin (Figure 4B, F, J), and uniform sculpture consisting of evenly sized radial elements. Some specimens examined herein compare well with the lectotype in colour (Figure 4I–K), while some specimens show some variation, with reddish-brown tones (Figure 4E–H). The occurrence reported here is within the known range of the species.

Genus Emarginula Lamarck, 1801

Type species: Emarginula conica Lamarck, 1801 [= Emarginula fissura (L.)] by monotypy; Recent, Eastern Atlantic.

Emarginula suspira Simone & Cunha, 2014

(Figures 5A–E, 6A–E)

Figure 5.

Fissurellid types: (A–E) Emarginula suspira Holotype MNHN IM-2000-25310, Vitória–Trindade Chain; (A) apical view (L = 6.8 mm, W = 4.7 mm); (B) apertural view; (C) left lateral view (H = 2.9 mm); (D) posterior view; (E) anterior view. (F–J) Hemimarginula hemitoma Holotype MNHN IM-2000-25324, from the Vitória–Trindade Chain: (F) apical view (L = 4.6 mm, W = 3.7 mm); (G) left lateral view (H = 2.8 mm); (H) apertural view; (I) anterior view; (J) posterior view. (K–M) Emarginula dentigera Holotype ANSP 61940, from Bermuda: (K) apical view (L = 5.7 mm, W = 4.5 mm); (L) apertural view; (M) left lateral view (H = 1.6 mm). Photos are courtesy of the ANSP and MNHN.

Figure 6.

Emarginula suspira and Hemimarginula hemitoma from Canopus Bank: (A–E) Emarginula suspira MZSP 70823: (A) apical view (L = 8.0 mm, W = 5.2 mm); (B) apertural view; (C) posterior view (H = 2.17 mm); (D) anterior view; (E) left lateral view. (F–J) Hemimarginula hemitoma MZSP 131277: (F) left lateral view (H = 3.05 mm); (G) apical view (L = 5.01 mm, W = 3.79 mm); (H–I) specimen #2: (H) apical view (L = 6.55 mm, W = 4.65 mm); (I) posterior view (H = 3.2 mm); (J) anterior view.

Synonymy see Simone and Cunha (Reference Simone and Cunha2014). Complement:

Emarginula suspira Simone and Cunha, Reference Simone and Cunha2014: 453, figs. 90–102; Cavallari et al., Reference Cavallari, Dornellas and Simone2016a: 48.

Distribution: Previously known from the Vitória–Trindade Chain, off southeastern Brazil (Simone and Cunha, Reference Simone and Cunha2014); expanded herein to Canopus Bank, off the state of Ceará, northeastern Brazil.

Habitat: Coralline bottoms, 54–940 m, as empty shells only (Simone and Cunha, Reference Simone and Cunha2014; present study).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 105522, 2 sh (viii/2005), MZSP 131278, 1 sh (viii/2005), MZSP 170745, 1 sh (viii/2005); 260 m, MZSP 70283, 2 sh (xi/2005), MZSP 90277, 1 sh (xi/2005). Additional material: Holotype MNHN IM-2000-25310. Paratypes: MNHN IM-2000-25311, 16 sh, MZSP 102932, 5 sh, MZSP 102939, 2 sh, MNRJ 25959, 3 sh, all from the type locality. BRAZIL; Espírito Santo (Bouchet, Leal and Métivier col.): off Itaúnas, Abrolhos Slope, MD 55 sta. DC73, 18°59′S, 37°48′W, 607–620 m, MNHN IM-2000-25312, 5 sh (27/v/1987); off Regência, MD55 sta. CB77, 19°40′S, 37°48′W, 790–940 m, MNHN IM-2000-25313, 2 sh, MZSP 102921, 1 sh (27/v/1987); off Conceição da Barra, MD55 sta. CB76, 18°58′S, 37°49′W, 637 m, MNHN IM-2000-25314, 1 sh (27/v/1987); Jaseur Seamount, MD55 sta. DC34, 20°27′S, 35°54′W, 54 m, MNHN IM-2000-25315, 1 sh (15/v/1987); Montague Seamount, MD55 sta. CB79, 20°26′S, 36°41′W, 310–350 m, MNHN IM-2000-25316, 1 sh (14/v/1987).

Measurements (in mm): Largest undamaged specimen (MZSP 131278), L = 8.4, W = 6.0, H = 3.2.

Remarks: Simone and Cunha (Reference Simone and Cunha2014) described this species in their account of the Fissurellidae collected by the MD55 expedition, redefining Brazilian samples previously misidentified as E. tuberculosa (Libassi, 1859), an Italian fossil. The present specimens can be identified as E. suspira by the characteristic outline (Figure 6C, D) and conspicuous sculpture consisting of radial ribs crossed by concentric cords (Figure 6A). They also compare well with the types examined herein (Figure 5A–E). The present record is the second to date and far removed from the original distribution, representing an impressive range expansion of over 1,900 km northward, from the Vitória–Trindade Chain (21°S) to northeastern Brazilian waters (2°S).

Genus Hemimarginula McLean, 2011

Hemimarginula McLean, Reference McLean2011: 412, figs. 1–2, 13–18.

Type species: Emarginula dentigera Heilprin, 1889 by original designation; Recent, Western Atlantic.

Hemimarginula hemitoma Simone & Cunha, 2014

(Figures 5F–J, 6F–J)

Synonymy see Simone and Cunha (Reference Simone and Cunha2014). Complement:

Emarginula pumila: Farfante, Reference Farfante1947: 107 [in part]; Rios, Reference Rios1970: 16; Métivier, Reference Métivier1972a: 63 [in part]; Rios, Reference Rios1975: 13 [in part]; Vokes and Vokes, Reference Vokes and Vokes1983: 11, 49, pl. 1, fig. 1; Rios, Reference Rios1985: 11 [in part]; Díaz and Puyana, Reference Díaz and Puyana1994: 108 [in part]; Rios, Reference Rios1994: 23 [in part]; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009: 620 [in part]; Tunnell et al., Reference Tunnell, Andrews, Barrera and Moretzsohn2010: 108 [in part]; Daccarett and Bossio, Reference Daccarett and Bossio2011: 48 [in part].

Emarginula tumida: Morretes, Reference Morretes1949: 55 [non Sowerby, 1874].

Hemimarginula hemitoma Simone and Cunha, Reference Simone and Cunha2014: 463, figs. 140–151; Cavallari et al., Reference Cavallari and Simone2016: 28.

Distribution: Previously known from waters off Espírito Santo state, southeastern Brazil (Simone and Cunha, Reference Simone and Cunha2014); expanded herein to Canopus, off the state of Ceará, northeastern Brazil.

Habitat: Biogenic sediment bottoms, 1–260 m (empty shells only; Simone and Cunha, Reference Simone and Cunha2014; present work).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 131277, 5 sh + fragments (viii/2005). Additional material: Holotype MNHN IM-2000-25324, Brazil, Espírito Santo, off Itaúnas, Abrolhos Slope, MD55 sta. DC83, 18°50′S, 37°57′W, 60 m (28/v/1987). Paratypes: MZSP 102947, 2 sh, from type locality; Brazil, Espírito Santo: off Itaúnas, Abrolhos Slope, MD55 sta. DC82, 18°56′S, 37°52′W, 85–105 m (28/v/1987), MNHN IM-2000-25326, 4 sh, MZSP 102948, 3 sh; Jaseur Seamount, MD55 sta. DC34, 20°27′S, 35°54′W, 54 m (15/v/1987), MNHN IM-2000-25327, 1 sh; Trindade Island, Enseada dos Portugueses, 20°30′15″S, 29°18′46″W, 10–12 m, MNHN IM-2000-25881, 3 sh (Bouchet col., v/1987); Andradas Beach, 20°30′50″S, 29°18′20″W, 0–1 m, MZSP 101247, 1 sh (Simone col., 24/vii/2011).

Measurements (in mm; n = 5): L = 6.1 ± 1.2, W = 4.6 ± 0.9, H = 2.8 ± 0.4.

Remarks: This species was long identified as Hemimarginula pumila (Adams, 1851) or its synonyms in revisions and local catalogues. Several authors have reported it from Brazil, but at least some of these records, based on published figures, correspond to H. hemitoma. It can be readily distinguished from H. pumila and another regional congener, Hemitoma pileum (Heilprin, 1889), by its delicate, radially arranged square pits formed by the intersection of radial and commarginal sculpture elements (Figure 6H) and its overall narrower radial ribs (Simone and Cunha, Reference Simone and Cunha2014). Simone and Cunha (Reference Simone and Cunha2014) also noted its similarity to H. dentigera (Heilprin, 1889), emphasising the taller height/length ratio (40–60% vs. 27% in H. dentigera) and the presence of double-lined radial pits on the outer surface as key diagnostic traits. Both features are consistent in the Canopus specimens, particularly the height/width proportions (Figures 5G, I, 6F, I). Examination of the holotype of H. dentigera (ANSP 61940; Figure 5K–M) reveals additional differences, including the ellipsoid outline of H. hemitoma (vs. oval in H. dentigera), a posteriorly displaced apex (vs. more central in H. dentigera), and a greater number of radial ribs (40–50 vs. 18–26; see also Teskey, Reference Teskey1973).

The present records are very distant from the original known distribution in southeastern Brazil, representing a range expansion of over 1,900 km northward, from the Vitória–Trindade Chain (21°S) to northeastern Brazilian waters (2°S). Considering that some records attributed to H. pumila actually represent H. hemitoma, the species’ distribution is likely not as disjunct as currently reported. Nonetheless, a comprehensive review of material from other localities is needed to confirm this.

Genus Lucapina Sowerby I, 1835

Synonymy see Dall (Reference Dall1915: 437) and Farfante (Reference Farfante1943a: 14).

Type species: Lucapina elegans Sowerby I, 1835 (= Lucapina sowerbii Sowerby I, 1835) by subsequent designation (Dall, Reference Dall1915); Recent, Atlantic.

Lucapina aegis (Reeve, 1850)

(Figure 7A–H)

Figure 7.

Diodora and Lucapina: (A–H) Lucapina aegis: (A, B) Syntype NHMUK 3510939: (A) apical view (L = 34 mm, W = 18 mm); (B) apertural view. (C–E) MZSP 131284 from Canopus: (C) apical view (L = 7.3 mm, W = 4.2 mm); (D) apertural view; (E) left lateral view (H = 2.2 mm). (F–H) adult specimen, MZSP 121163 from Santos, off SE Brazil: (F) apical view (L = 23.0 mm, W = 12.2 mm); (G) apertural view; (H) left lateral view (H = 5.8 mm); (I–J) Lucapina elisae Paratype MZSP 61229, from Canopus Bank: (I) apical view (L = 50.0 mm, W = 33.0 mm); (J) apertural view; (K–M) Diodora tanneri USNM 43765 Holotype, from Delaware Bay: (K) apical view (L = 43.5 mm, W = 30 mm); (L) apertural view; (M) right lateral view (H = 15 mm); (N–P) Lucapina elisae MZSP 93931 from Canopus Bank: (N) apical view (L = 17.4 mm, W = 11.3 mm); (O) apertural view; (P) detail of postero-median left region showing the reticulate sculpture.

Synonymy see Métivier (Reference Métivier1972b). Complement:

Fissurella aegis Reeve, Reference Reeve1850: p. XI, fig. 72.

Lucapina aegis: Matthews and Kempf, Reference Matthews and Kempf1970: 17; Rios, Reference Rios1970: 19; Métivier, Reference Métivier1972a: 66; Reference Métivier1972b: 407; Abbott, Reference Abbott1974: 25, fig. 117; Rios, Reference Rios1975: 16; Reference Rios1985: 15; Reference Rios1994: 27; Díaz and Puyana, Reference Díaz and Puyana1994: 111, pl. 34, fig. 332; Lyons, Reference Lyons, Camp, Lyons and Perkins1998: 16; Redfern, Reference Redfern2001: 7, pl. 4, fig. 29, Reference Redfern2013: 5, fig. 10; García and Lee, Reference García and Lee2002: 11; Rios, Reference Rios2009: 36, fig. 74; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009: 620; Tunnell et al., Reference Tunnell, Andrews, Barrera and Moretzsohn2010: 110, text fig.; Daccarett and Bossio, Reference Daccarett and Bossio2011: 49, fig. 37; Espinosa et al., Reference Espinosa, Ortea, Sanchez and Gutiérrez2012: 56; Diez-García, Reference Diez-García2016: 104.

Distribution: From East Florida to Brazil (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009).

Habitat: From 0–55 m depths (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009), up to 260 m (empty shells only; present study).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 131284, 5 sh (viii/2005), MZSP 170746, 2 sh (viii/2005). Additional material: Syntype NHMUK 1984194, unknown locality, former Hugh Cumming Collection. BRAZIL; São Paulo: Santos, Irararé Beach, 23°57′S, 46°18′W, MZSP 121163, 8 sh (J. Colella col., vii/1968).

Measurements (in mm): Largest specimen, L = 7.3, W = 4.2, H = 2.2.

Remarks: Farfante (Reference Farfante1943a) indicated that the types of L. aegis were likely housed at the British Museum. Correspondence with NHMUK staff confirmed the presence of a syntype (NHMUK 1984194, Figure 7A, B). Although juvenile, the features of the present specimens agree well with published redescriptions and illustrations, particularly the juvenile shell figured by Redfern (Reference Redfern2013: 4, fig. 10). Farfante (Reference Farfante1943a) described the species as light brown to olive green with darker rays and noted the characteristic triangular foramen callus (Figure 7B, D, G), all features also observed in the Canopus material. According to Farfante (Reference Farfante1943a), the species reaches up to 35 mm in length. Its colouration appears to change markedly with growth: shells exceeding approximately 15 mm often develop dark green margins (Figure 7F, H), a transition possibly indicated by the marginal greenish hue in one of the specimens examined here (Figure 7C).

The distinctive ontogenetic colour transition of L. aegis distinguishes it from nearly all other local congeners. It further differs from the sympatric L. philippiana (Finlay, 1930) by its larger size (maximum length 35 vs. 18 mm; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009) and sharper, more robust sculpture; from L. sowerbii by being slightly larger (35 vs. 30 mm; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009) and exhibiting fewer ribs and cords; and from L. suffusa (Reeve, Reference Reeve1850) by its sharper sculpture with more numerous, narrower radial ribs and concentric cords, as well as a proportionally smaller foramen. Compared to the Brazilian L. elisae Costa and Simone, Reference Costa and Simone2006, L. aegis is much smaller (35 vs. 60.5 mm), with a lower profile, proportionally larger foramen, and stronger but fewer ribs and cords.

This species has been recorded from Brazilian waters since Rios (Reference Rios1970) and Matthews and Kempf (Reference Matthews and Kempf1970), with subsequent catalogues reiterating these reports (Abbott, Reference Abbott1974; Rios, Reference Rios1994, Reference Rios2009; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009). Documented occurrences include the Fernando de Noronha Archipelago, Trindade Island, and Rocas Atoll. The specimens examined herein fall within the known geographic range of L. aegis but extend its bathymetric distribution from the previously reported 0–55 m to a maximum depth of 260 m. It should be noted, however, that all material examined consists of empty shells.

Lucapina elisae Costa & Simone, Reference Costa and Simone2006

(Figure 7I–J, N–P)

Lucapina elisae Costa and Simone, Reference Costa and Simone2006: 1, figs. 1–18; Pimenta et al., Reference Pimenta, Monteiro, Barbosa, Salgado and Coelho2014: 63.

Distribution: Known only from the type locality at Canopus Bank.

Habitat: Benthos, on biogenic sediment, 240–260 m.

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 260 m, MZSP 90276, 1 sh + fragment (xi/2005), MZSP 93931, 4 sh (juveniles; xi/2005). Additional material: Holotype MNRJ 10661, Brazil, Ceará, Canopus Bank, off Fortaleza, 02°14′25″S, 38°22′50″W, 240–260 m depth (J. Coltro and P.M. Costa col., xi/2005). Paratypes: MZSP 61229, 9 spm (6 lacking respective shells); MZSP 53934, 3 sh; MZSP 78194, 1 sh; MNRJ 10680, 2 sh; MNRJ 10681, 1 sh; MNRJ 10683, 2 sh; MORG 46442, 1 sh; all from the type locality. Diodora tanneri: Holotype USNM 43765, USA, off the cape south of Delaware, R/V Fish Hawk, Sta. 1046, 190 m (USFC col., 10/viii/1881).

Measurements (in mm): Largest specimen (MZSP 93931), L = 17.5, W = 11.3, H = 5.0.

Remarks: This large deep-water species differs from other Brazilian fissurellids primarily by its size, in addition to a proportionally small foramen and relatively thin shell. The reticulate sculpture consists of rounded axial riblets overrun by thin concentric ridges (Figure 7I, N, P). In the original description, Costa and Simone (Reference Costa and Simone2006) cited the posterior position of the foramen as a diagnostic character, contrasting it with the supposedly more central foramen of the similarly sized Caribbean species D. tanneri (Verrill, Reference Verrill1882). Examination of the holotype of D. tanneri, however, shows the foramen to be located in the posterior third of the shell length (Figure 7K), as in L. elisae. Although D. tanneri is clearly different in external colouration, the shell measurements (including height-width and length-width ratios) of the holotype are closer to those reported for L. elisae. Shell proportions in some fissurellids are nevertheless known to vary intra-specifically (Farfante, Reference Farfante1943a, Reference Farfante1943b).

The reticulate sculpture pattern (Figure 7P), also described by Verrill (Reference Verrill1882) in D. tanneri, is shared by both species (Figure 7I, K, N), though the ribs and lines appear less pronounced in D. tanneri. While Costa and Simone (Reference Costa and Simone2006) emphasised differences in the number of radial lines, such features are subject to both ontogenetic and intra-specific variation in some fissurellids (Farfante, Reference Farfante1943a, Reference Farfante1943b). Thus, despite some clear distinctions between the two taxa, the possibility that L. elisae represents a junior subjective synonym of D. tanneri cannot be entirely dismissed and merits further investigation using anatomical and molecular data.

Genus Lucapinella Pilsbry, 1890

Synonymy see McLean (Reference McLean1967: 349).

Type species: Clypidella callomarginata Dall, 1871 by subsequent designation (Pilsbry, 1890); Recent, Pacific.

Lucapinella limatula (Reeve, 1850)

(Figure 8)

Figure 8.

Lucapinella limatula MZSP 170747 from Canopus Bank: (A) apical view (L = 7.0 mm, W = 4.1 mm); (B) apertural view; (C) left lateral view (H = 1.8 mm).

Synonymy see Farfante (Reference Farfante1943a) and Métivier (Reference Métivier1972b). Complement:

Lucapinella limatula: Farfante, Reference Farfante1943a: 19, pl. 5, figs. 1–3; Abbott, Reference Abbott1954: 98, pl. 17, fig. i; Rios, Reference Rios1970: 18; Métivier, Reference Métivier1972a: 67; Reference Métivier1972b: 408; Abbott, Reference Abbott1974: 26, fig. 120; Matthews and Rios, Reference Matthews and Rios1974: 48; Ekdale, Reference Ekdale1974: 641; Rios, Reference Rios1975: 16, pl. 3, fig. 27; Vokes and Vokes, Reference Vokes and Vokes1983: 11, 49, pl. 1, fig. 13; Brattström, Reference Brattström1985: 201, tab. 2; Rios, Reference Rios1985: 15, pl. 7, fig. 60; Reference Rios1994: 28, pl. 8, fig. 70; Díaz and Puyana, Reference Díaz and Puyana1994: 111, pl. 34, fig. 335; Capelo and Buitrago, Reference Capelo and Buitrago1998: 117, tab. 1; Lyons, Reference Lyons, Camp, Lyons and Perkins1998: 16; Redfern, Reference Redfern2001: pl. 4, fig. 33; Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009: 147; Rios, Reference Rios2009: 38, text fig.; Palacio et al., Reference Palacio, Gracia and Duque2010: 403, tab. 2; Tunnell et al., Reference Tunnell, Andrews, Barrera and Moretzsohn2010: 111, text fig.; Daccarett and Bossio, Reference Daccarett and Bossio2011: 50, fig. 40; Espinosa et al., Reference Espinosa, Ortea, Sanchez and Gutiérrez2012: 56; Redfern, Reference Redfern2013: 6, fig. 13; Pádua et al., Reference Pádua, Silva and Duarte2019: 113; Calzadilla-Milian et al., Reference Calzadilla-Milian, Armiñana-garcía, Sarría-martínez, Fimia-duarte, Iannacone, Grandía-guzmán and Castillo-fleites2020: 297.

Distribution: From North Carolina to Brazil (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009).

Habitat: Sublittoral, 0–146 m (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009), up to 260 m (empty shells only; present study).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 170747, 3 sh (viii/2005).

Measurements (in mm): Largest specimen, L = 7.0, W = 4.1, H = 1.8.

Remarks: As with another fissurellid species treated herein (e.g., L. aegis), the type material of L. limatula was not specified by Reeve. Farfante (Reference Farfante1943a) suggested it should be housed at the British Museum; however, correspondence with NHMUK staff revealed that no such specimens are currently held there (A. Salvador, pers. comm.). Despite this, the Canopus specimen agrees well with Farfante’s (Reference Farfante1943a) redescription, particularly in its large foramen, upturned shell margins, and sculpture of alternating large and small radial ribs and riblets intersected by concentric laminae forming scale-like, upward-oriented projections (Figure 8A, C). Among local congeners, L. limatula differs from L. henseli (Martens, 1900) by its smaller size (maximum length 18 vs. 27.8 mm; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009), alternating radial sculpture, and the presence of erect, scale-like projections. This species has been commonly reported from Brazil since at least the late 1940s (Morretes, Reference Morretes1949), appears in virtually every local catalogue, and is recorded along the entire Brazilian coast (Rios, Reference Rios1994, Reference Rios2009). The present material extends its known bathymetric range from 146 to 260 m.

Genus Profundisepta McLean & Geiger, 1998

Type species: Puncturella profundi Jeffreys, 1877, by original designation; Recent, Atlantic.

Profundisepta volcano (Simone and Cunha, 2014) comb. nov.

(Figure 9)

Figure 9.

Profundisepta volcano comb. nov. MZSP 170748, from Canopus Bank: (A) apical view (L = 3.4 mm, W = 2.5 mm); (B) apertural view; (C) left lateral view (H = 1.25 mm); (D–J) 3D reconstruction of shell through CT (voxel size = 2.78 μm): (D) right lateral view; (E) apical view; (F) apertural view showing intritacalx pores; (G) left lateral view; (H) right lateral view, detail of protoconch; (I) anterior view; (J) posterior view.

Puncturella volcano Simone and Cunha, Reference Simone and Cunha2014: 459, figs. 116–120.

Distribution: Previously known only from the type locality off southeastern Brazil; expanded herein to Canopus, off the state of Ceará, northeastern Brazil.

Habitat: Benthos, 240–620 m (empty shells only; Simone and Cunha, Reference Simone and Cunha2014; present work).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 170748, 2 sh (viii/2005). Additional material: Holotype MNHN 25328, Brazil, Espírito Santo, off Itaúnas, continental slope of Abrolhos, 18°59′S 37°48′W (MD55 sta. DC73).

Measurements (in mm): Holotype, L = 3.8, W = 1.3; largest specimen (MZSP 170748), L = 3.4, W = 2.5, H = 1.25.

Remarks: This very small and apparently extremely rare species was originally described in 2014 from a single specimen collected by the MD55 expedition off southeastern Brazil, in the Vitória–Trindade Seamount Chain, specifically on the Abrolhos Slope, at a depth of 607–620 m. The two shells examined herein are proportionally slightly taller than the holotype (height in the largest specimen analysed is ca. 37% of length) but are otherwise very similar. The protoconch of the holotype was damaged or detached, precluding its description (Simone and Cunha, Reference Simone and Cunha2014); however, it is preserved in both specimens examined herein (Figure 9D, G, H, J). It consists of a single (200 μm) whorl, with a well-marked transition to the teleoconch expressed as an axial depression followed by a slight thickening of the lip (Figure 9H). The protoconch is also slightly tilted leftward relative to the shell’s antero-posterior axis (Figure 9J). More importantly, its rough, pitted surface (Figure 9H) is diagnostic of the genus Profundisepta McLean and Geiger, Reference McLean and Geiger1998. Based on the specimens examined, the species is characterised by its small size; moderately high shell (Figure 9C, D, G); subapical, triangular foramen (Figure 9A, E, I); half a smooth apical whorl retained in the teleoconch before the expansion (Figure 9G); and small selenizone (Figure 9A, E), all of which fall within the diagnosis of Profundisepta as defined by McLean and Geiger (Reference McLean and Geiger1998). Accordingly, the new combination P. volcano comb. nov. is proposed herein.

Additionally, in their original description, Simone and Cunha (Reference Simone and Cunha2014) did not examine the holotype under SEM, which likely limited the accuracy of their observations on the outer and inner shell surfaces. Based on the tomographic reconstructions analysed herein, the external surface exhibits an irregular, coarse sculpture composed of unevenly distributed pustules and low, confluent ridges (Figure 9D, E, G, I–J). These elevations vary in size and are separated by shallow, poorly defined depressions, resulting in a rugged, non-uniform appearance. Towards the apex, the sculpture becomes more irregular, with fused nodules forming short, sinuous crests (Figure 9G–H). Near the shell base, approximately five deep, closely spaced, discontinuous, thin commarginal grooves are present. Overall, the outer texture resembles solidified molten lava on a volcanic slope, aptly reflecting the etymology of the specific name. The inner surface is mostly smooth but bears well-defined intritacalx pores (see Herbert and Kilburn, Reference Herbert and Kilburn1986), and roughly circular depressions concentrated near the shell margin, some of which extend axially towards the central area, forming elongated grooves (Figure 9F). The possible presence of intritacalx is also expressed as irregular white axial markings on the otherwise semi-translucent shell both in the specimens examined herein (Figure 9A, B) and the holotype (Simone and Cunha, Reference Simone and Cunha2014: figs. 116–119).

The present records constitute only the second occurrence of the species and are far removed from its type locality, representing a remarkable range extension of over 1,900 km northward, from the Vitória–Trindade Chain (21°S) to northeastern Brazil (2°S). They also represent a significant bathymetric expansion to shallower waters, up to 240–260 m depths.

Genus Puncturella Lowe, 1827

Synonymy see Cunha et al. (Reference Cunha, Lemer, Bouchet, Kano and Giribet2019). Complement:

Puncturella (Craniopsis) [sic]: Nordsieck, Reference Nordsieck1968: 12.

Type species: Patella noachina Linnaeus, 1771, by monotypy; Recent, Atlantic.

Puncturella canopa (Simone & Cunha, 2014) comb. nov.

(Figure 10A–F)

Figure 10.

Puncturella from Canopus Bank: (A–F) Puncturella canopa comb. nov.: (A) MZSP 66603, apical view (L = 3.13 mm); (B–F) MZSP 72059 from Canopus: (B) apertural view; (C) apical view (L = 4.21 mm); (D) right lateral view (H = 2.55 mm); (E) posterior view (W = 2.77 mm); (F) anterior view; (G–L) Puncturella columbaris comb. nov., MZSP 170750, 3D reconstruction of shell through CT (voxel size = 3.0 μm): (G) apical view (L = 2.37 mm, W = 1.67 mm); (H) apertural view; (I) posterior view (H = 1.63 mm); (J) protoconch detail; (K) anterior view; (L) right lateral view.

Cranopsis canopa Simone and Cunha, Reference Simone and Cunha2014: 449, figs. 76–83; Cavallari et al., Reference Cavallari and Simone2016: 13.

Distribution: Known only from the type locality at Canopus Bank.

Habitat: Benthos, 60–260 m (empty shells only; Simone and Cunha, Reference Simone and Cunha2014; present work).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 60 m, MZSP 53944, 11 sh (viii/2005); 260 m, MZSP 67298, 11 sh (viii/2005), MZSP 70319, 50 sh (xi/2005). Additional material: Holotype MZSP 107718, Brazil, Ceará, off Fortaleza, Canopus Bank, 2°12′43″S, 38°18′52″W, 250 m (Coltro col., viii/2005). Paratypes: MNHN IM-2000-25309, 5 sh, MNRJ 30825, 2 sh, UF Mollusca 451489, 2 sh, USNM 1207437, 2 sh, MZSP 90281, 24 sh, MZSP 94183, 11 sh, all from the type locality.

Measurements (in mm): Largest specimen (MZSP 67298), L = 3.1, W = 2.0.

Remarks: This apparently rare species is known only from Canopus, its type locality. The new combinations herein follow the synonymisation of Cranopsis with Puncturella after Cunha et al. (Reference Cunha, Lemer, Bouchet, Kano and Giribet2019). Only a few specimens were recovered from the studied samples. Although Simone and Cunha (Reference Simone and Cunha2014) did not consider the semitranslucent, lustrous shell of P. canopa comb. nov. to be diagnostic, this feature is clearly present in both the well-preserved specimens examined here (Figure 10E–F) and in the holotype (Figure 10A–C). Post-mortem calcification, likely due to local environmental conditions, often renders Canopus shells opaque and dull (Figure 10H–K), which may have obscured this trait in some individuals. In addition to the diagnostic characters noted by Simone and Cunha (Reference Simone and Cunha2014), primarily shell proportions and sculpture element counts, the translucent, glossy shell of P. canopa comb. nov. further differentiates it from the similar P. tuberculata (Watson, Reference Watson1883), which also bears conspicuous granulations across its outer surface (Farfante, Reference Farfante1947: pl. 54, figs. 4–5).

Watson’s (Reference Watson1883) description of C. tuberculata was based on fossil material from the Miocene of Italy, and we believe it is unlikely that the Caribbean specimens belong to the same taxon despite the conchological similarity. Nevertheless, the name has been considered a nomen nudum (Simone, Reference Simone2024b). The bathymetric range of P. canopa comb. nov. is expanded based on the currently analysed material, from 250 m to a range of 60–260 m, with well-preserved individuals coming from shallower depths.

Puncturella cearensis (Simone and Cunha, 2014) comb. nov.

(Figure 11C–J)

Figure 11.

Puncturella spp.: (A, B) Puncturella antillana Holotype MCZ 160518 (L = 11.5 mm, W = 10 mm): (A) apical view; (B) apertural view; (C–D) Puncturella cearensis comb. nov. Holotype MZSP 106894, from Canopus Bank: (C) apical view (L = 13.0 mm); (D) left lateral view; (E–G) MZSP 53944 from Canopus Bank; (E) apical view (L = 9.18 mm); (F) apertural view; (G) left lateral view (H = 3.96 mm); (H–J) MZSP 170749 from Canopus, 3D reconstruction of juvenile shell through CT (voxel size = 4.0 µm); (H) apertural view showing internal punctuations; (I) apical view; (J) right lateral view in detail showing protoconch.

Cranopsis cearensis Simone and Cunha, Reference Simone and Cunha2014: 445, figs. 48–55; Cavallari et al., Reference Cavallari and Simone2016: 15.

Distribution: Known only from the type locality at Canopus Bank.

Habitat: Benthos, 60–260 m (Simone and Cunha, Reference Simone and Cunha2014; present work).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 60 m, MZSP 53944, 11 sh (viii/2005); 260 m, MZSP 67298, 11 sh (viii/2005), MZSP 70319, 50 sh (xi/2005), MZSP 170749, 10 sh (xi/2005). Additional material: Holotype MZSP 106894, Brazil, Ceará, off Fortaleza, Canopus Bank, 2°12′43″S, 38°18′52″W, 250 m (Coltro col., viii/2005). Paratypes: MNHN IM-2000-25299, 1 sh, MNRJ 30824, 1 sh, MZSP 93940, 18 sh, MZSP 90280, 19 sh, MZSP 100415, 2 sh, all from the type locality.

Measurements (in mm; n = 14): L = 12.4 ± 1.0, W = 10.2 ± 1.0, H = 5.0 ± 0.5.

Remarks: This species is currently known only from Canopus. No live individuals or specimens with soft parts have yet been collected, and their anatomy therefore remains unknown. Puncturella cearensis comb. nov. can be distinguished from the similar Caribbean congener P. antillana (Farfante, Reference Farfante1947; Figure 11A, B) by its larger septum (Figure 11E, F), higher and more widely spaced radial ribs (Figures 11C, E, I), and the projection of these ribs forming strong undulations along the shell margin (Figure 11D, G, I). The teleoconch sculpture of P. cearensis comb. nov. is also more pronounced, beginning with weaker elements that become abruptly well-marked after approximately half a teleoconch whorl (Figure 11J). In addition, P. cearensis comb. nov. shows an elliptical outline in apertural/apical view (Figure 11F, H), whereas P. antillana is oval, narrowing posteriorly (Figure 11A, B).

Although Simone and Cunha (Reference Simone and Cunha2014) described the inner surface of P. cearensis comb. nov. as smooth, closer inspection of their fig. 53 shows rows of radially arranged circular intritacalx pores on the paratype (MZSP 93940), despite some surface wear. The same feature is confirmed herein in the illustrated juvenile specimen (Figure 11H). This had also been noted by those authors for P. nymphalis (as Cranopsis nymphalis). Moreover, the outer surface of P. cearensis comb. nov. likewise bears intritacalx pores, clearly visible on the initial whorls (Figure 11J), which is expected since inner and outer pores are interconnected (Herbert and Kilburn, Reference Herbert and Kilburn1986).

Based on the present material, P. cearensis comb. nov. appears to be particularly abundant in Canopus, as indicated by the large number of specimens recovered in the studied sample. Its bathymetric distribution is also expanded from the previously known fixed depth of 250 m to a range of 60–260 m, although all records are based solely on empty shells.

Puncturella columbaris (Simone & Cunha, 2014) comb. nov.

(Figure 10G–L)

Cranopsis columbaris Simone and Cunha, Reference Simone and Cunha2014: 452, figs. 84–89; Cavallari et al., Reference Cavallari and Simone2016: 17.

Distribution: Known only from the type locality at Canopus Bank.

Habitat: Benthos, sandy bottoms with gravel, 250 m (empty shells only; Simone and Cunha, Reference Simone and Cunha2014).

Material examined: Holotype MZSP 107719; Paratypes MZSP 105520, 3 sh, from type locality, same data as holotype. Additional material: from type locality, 240–260 m, MZSP 170750, 7 sh (viii/2005).

Measurements (in mm; n = 6): L = 2.2 ± 0.2, W = 1.5 ± 0.1, H = 1.3 ± 0.2.

Remarks: This species can be identified by its conspicuous radial sculpture of spaced cords bearing triangular pustules and by the foramen with tall lateral edges (Figure 10K). Additional features include the well-marked selenizone (Figure 10G, I), the pair of pronounced radial cords that laterally delimit the foramen scar on the anterior slope of the shell (Figure 10G, K), and the flat, straight septum (Figure 10H). The length/width/height ratios emphasised by Simone and Cunha (Reference Simone and Cunha2014) appear to be quite variable in the limited material examined herein (ca. 8–15%) and may therefore be of limited taxonomic value. Although not mentioned by Simone and Cunha (Reference Simone and Cunha2014), the specimens examined herein show roughly radially arranged rows of circular intritacalx pores, well-marked between the radial cords on the external shell surface (Figure 10G, K, L), particularly on the initial whorl near the protoconch (Figure 10J, L). These pores are also present internally, as expected for Puncturella (Herbert and Kilburn, Reference Herbert and Kilburn1986), though less conspicuously (Figure 10H). The specimens examined herein were collected at the type locality and appear slightly younger than the types, based on their measured proportions. Nevertheless, they expand the known bathymetric range of P. columbaris comb. nov. to 240–260 m.

Superfamily Trochoidea Rafinesque, 1815

Family Areneidae McLean, 2012

General remarks: Areneidae primarily comprise species formerly assigned to Liotiidae Gray, 1850 (Williams et al., Reference Williams, Karube and Ozawa2008; McLean, Reference McLean2012b). Members of the family are characterised by brightly coloured shells (in contrast to the typically colourless shells of Liotiidae), a predominantly spiral sculpture, a tangential aperture bearing denticles, and a lip preceded by a brief whorl expansion (McLean, Reference McLean2012b). The family currently includes the African genus Cinysca Kilburn, 1970, and the Atlantic-Pacific genus Arene Adams and Adams, 1854, which is represented in Brazil by 11 species (Dornellas, Reference Dornellas2024).

Genus Arene Adams & Adams, 1854

Type species: Turbo cruentatus Mühlfeld, 1824, by subsequent designation (Woodring, Reference Woodring1928); Recent, Atlantic.

Arene asteria Pedro, Cavallari & Simone, new species (Figure 12)

Arene bairdii: Rios and Barcellos, Reference Rios and Barcellos1979: 164 [in part; non Dall, Reference Dall1889].

Arene tricarinata: Rios, Reference Rios1985: 28 [in part; non Stearns, 1872].

Arene venusta: Leal, Reference Leal1991: pl. 4, figs. I–K; Rios, Reference Rios1994: 43, pl. 13, fig. 137; Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009: 147 [non Woodring, Reference Woodring1928].

ZooBank: TBD.

Type material: Holotype MZSP 170631. Paratypes: MZSP 170632, 10 sh (viii/2005), from type locality; MORG 19143, Atol das Rocas, R/V Almirante Saldanha sta. 1663A, 1 sh; MORG 20637, Fernando de Noronha Archipelago, Ponta da Sapata, 1 sh (i/1979), MORG 24666, same locality, 40 m, 1 sh (xii/1985).

Type locality: Brazil, Ceará state, 190 km off Fortaleza, Canopus Bank, 02°14′25″S, 38°22′50″W, 240–260 m.

Diagnosis: Shell small (max. width 3.3 mm), disc-shaped with cyrtoconoid spire and flattened apex, ivory white, distinctly wider than high, strongly sculptured by spiral cords and sinuous axial striae; three dominant cords on body whorl forming a keeled outline; peripheral cord most prominent, with fluted nodules, keeled in apical view. Base convex, with four to five spiral cords; periumbilical cords strong, coarsely nodulose.

Description: Shell (Figure 12A–K) 1.5× wider than high, with 4¾ convex whorls; colour white, occasionally with intermittent brown markings on spiral cords, aligned across adjacent cords forming distinct axial bands on last whorl (Figure 12K). Spire cyrtoconoid, very short (∼1/6 of shell height; Figure 12A–C), broad, with flattened apex; spire angle ∼110°. Protoconch (Figure 12D, G) paucispiral (diameter = ∼240 μm), smooth, with 1 whorl, slightly lower than subsequent whorl; transition weakly demarcated by faint lip, followed by onset of teleoconch sculpture.

Figure 12.

Arene asteria new species: (A–H) Holotype MZSP 170631, 3D reconstruction of shell through CT (voxel size = 2.61 μm): (A) abapertural view (H = 1.8 mm, D = 2.6 mm); (B) left lateral view; (C) abapertural view; (D) apical view; (E) umbilical view; (F) detail of aperture, showing operculum; (G) detail of protoconch (arrow indicates transition); (H) apertural view, cross-section showing extent of umbilicus. (I–J) Paratype MORG 20637, 3D reconstruction of shell through CT (voxel size = 5.71 μm): (I) umbilical view; (J) apertural view (H = 3.29 mm, D = 4.56 mm); (K) Paratype MZSP 170632, apertural view (H = 1.9 mm, D = 2.7 mm).

Teleoconch (Figure 12A–D, J) of up to 3¾ whorls, profusely sculptured. Surface ornamented with spiral cords of variable width, densely marked by sinuous axial growth striae; weak axial ribs developed at nodular intersections, intercalated with six to eight axial striae (Figure 12B, C). First 1⅔ whorl with three spiral cords, upper cord very weak, bearing small ribs, becoming more pronounced and nodulose on subsequent whorls. Suture channelled, well-impressed, formed by junction of suprasutural and subsutural cords (Figure 12H). Body whorl with wider spiral cords, with three dominant cords, producing a keeled outline (Figure 12A–C, H, J); middle cord most prominent, with 25–27 larger fluted nodules, spirally raised and imbricated, slightly pointed in apical view (Figure 12D, K). Peristome circular, height ∼½ of shell height, slightly prosocline (∼10°); inner surface white to ivory-white. Inner lip thickened, flaring, producing distinct callus, bi-reflected towards umbilicus corresponding to periumbilical cords (Figure 12A, F, J). Outer lip crenulated (Figure 12F), crenulations congruent with external ornamentations. Shell base convex, with four to five spiral cords (Figure 12E, I); peripheral cord broader, weakly nodulose; two narrower, nodulose cords between peripheral and outermost periumbilical cord, interspace wide. Periumbilical cords equal in size or with the innermost cord slightly smaller; both with stronger, coarser nodules, intercrossed by axial ribs directed towards umbilicus. Umbilicus wide, deep, twisted, internally marked by fine axial lines.

Operculum (Figure 12A, F) mostly calcareous with a thin superficial corneous layer on the inside, circular, multispiral, with central nucleus, occupying entire aperture; composed of numerous well-marked concentric whorls. External surface bearing flabellate radial lamellae projecting outward, decreasing in size towards nucleus, imparting a strongly sculptured and imbricated aspect; internal surface strongly convex, smooth.

Distribution: Brazil, oceanic islands, seamounts, and continental shelf from Ceará to Rio de Janeiro (Leal, Reference Leal1991; Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009; present work).

Habitat: Benthos, biogenic sediment, 25–260 m (Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009; present study).

Etymology: From the Greek ἀστερία (astería), meaning ‘star’ or ‘starry’, used here as a noun in apposition. The epithet alludes to the type locality, Canopus, named after the star Alpha Carinae, the second-brightest star in the night sky, and also evokes the radiant, ornamented appearance of the new species’ shell. Asteria is also a Titan in Greek mythology, associated with oracles and the night sky, which further reinforces the celestial connotation of the name.

Material examined: Types.

Measurements (in mm): Holotype MZSP 170631, 3¾ whorls, H = 1.8, D = 2.6. Paratype MZSP 170632, 4 whorls, H = 1.9, D = 2.7; Paratype MORG 20637, 4¾ whorls, H = 3.3, D = 4.6.

Remarks: Arene asteria sp. nov. was previously identified by Leal (Reference Leal1991) as A. venusta (Woodring, Reference Woodring1928) based on material from the Fernando de Noronha Archipelago (Figure 12J herein is based on the same specimen illustrated by Leal in his pl. 4, fig. I). He also reassigned earlier records, identified as A. bairdii by Rios and Barcellos (Reference Rios and Barcellos1979) and as A. tricarinata by Rios (Reference Rios1985), to the same species. That interpretation was subsequently followed in later catalogues (Rios, Reference Rios1994, Reference Rios2009) and biogeographical studies (Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009; Barroso et al., Reference Barroso, Lotufo and Matthews-cascon2016). As already noted by Leal (Reference Leal1991), the Caribbean records identified as A. venusta most likely correspond to the similar Arene variabilis (Dall, Reference Dall1889). More importantly, Woodring’s A. venusta is a Miocene fossil from Bowden, Jamaica, which created a perplexing taxonomic situation, similar to that observed in Cranopsis tuberculosa (see above), that required clarification. The holotype of A. asteria sp. nov. bears a well-preserved operculum still attached to the aperture, demonstrating that the specimen was collected alive at that depth range. Notably, the operculum is strongly visible in tomographic images, appearing as a radiodense structure. This observation suggests that the operculum is mostly calcareous, a feature also reported for the congener A. flexispina (Leal and Coelho, Reference Leal and Coelho1985). It is also noteworthy that all specimens studied herein originate from insular and deep-sea environments.

Arene asteria can be distinguished from most Western Atlantic congeners by its (at least ∼20%) smaller size, and sculpture consisting of well-marked axial elements, spiral cords bearing pointy, fluted nodules, which give it a star-like aspect in apical view, and can also be differentiated from Western Atlantic congeners by the pattern of spiral cords on the shell base, which exhibit variable widths and broader interspaces, whereas in congeners, the cords are more regular in width and separated by narrower interspaces.

Arene bairdii (Dall, 1889)

(Figure 13A–C)

Figure 13.

Arene from Canopus Bank: (A–C) Arene bairdii MZSP 170751: (A) juvenile specimen, apertural view (H = 1.3 mm, D = 1.8 mm); (B) same, apical view; (C) adult specimen fragment, abapertural view. (D–L) Arene brasiliana: (D–F) MZSP 70236: (D) apertural view (H = 4.7 mm, D = 5.5 mm); (E) apical view; (F) umbilical view; (G–I) MZSP 131038, spm. #1: (G) apertural view (H = 4.8 mm, D = 5.5 mm); (H) apical view; (I) umbilical view; (J–L) MZSP 131038: (J) spm. #2, apertural view (H = 4.25 mm, D = 5.0 mm); (K) spm. #3, apertural view (H = 3.8 mm, D = 4.9 mm); (L) spm. #4, apertural view (H = 4.8 mm, D = 5.0 mm).

Synonymy see Leal (Reference Leal1991). Complement:

Liotia bairdii var. trullata Dall, Reference Dall1889: 389.

Liotia bairdi [sic]: Rios, Reference Rios1970: 28.

Arene bairdii: Rios, Reference Rios1975: 26, pl. 7, fig. 73; Leal, Reference Leal1991: 53; Rios, Reference Rios1994: 40, pl. 12, fig. 112; González, Reference González1998: 626; Lyons, Reference Lyons, Camp, Lyons and Perkins1998: 16; García and Lee, Reference García and Lee2002: 11; Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009: 147; Rios, Reference Rios2009: 63, fig. 146; Oliveira, Reference Oliveira, Tâmega, Oliveira and Figueiredo2013: 47, fig. 34; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021: 92, figs. A–B.

Distribution: From North Carolina to Brazil (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009), in Brazil from the states of Amapá to Rio Grande do Sul, including oceanic islands (Leal, Reference Leal1991; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021).

Habitat: Benthos, biogenic sediment, 27–1,472 m (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009; present study).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 170751, 1 juvenile sh + fragment (viii/2005).

Measurements (in mm): Single juvenile specimen, 3½ whorls, H = 1.3, D = 1.8.

Remarks: This species is widely distributed in the Western Atlantic (Leal, Reference Leal1991; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021), and the records from Canopus fall within its known range. It can be recognised by its cyrtoconoid shell with a flattened apex and channelled suture; sculpture consisting of spiral cords with conspicuous, mostly rounded nodules; and colouration ranging from brownish to reddish, intermixed with yellowish and whitish-cream tones (Figure 13A, B) (Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021). In the Canopus samples, however, the species is represented only by a juvenile shell (Figure 13A, B) and a fragmentary adult specimen (Figure 13C). Although somewhat similar in colour and size range to Arene lychee (see below; Leal, Reference Leal1991), A. bairdii is readily distinguished by its flat apex and spiral cords bearing smaller, rounder, and more numerous nodules (Figure 13C). These differences are evident even in juveniles, as shown by the contrasting height-to-width ratios and spire height of A. bairdii (Figure 13A) versus A. lychee (Figure 15D). The records from Canopus are within the known occurrence and depth range of the species.

Arene brasiliana (Dall, 1927)

(Figure 13D–L)

Synonymy see Leal (Reference Leal1991). Complement:

Liotia brasiliana: Morretes, Reference Morretes1949: 61.

Arene brasiliana: Rios, Reference Rios1970: 29, pl. 3; Reference Rios1975: 26, pl. 7, fig. 74; Reference Rios1985: 27, pl. 12, fig. 116; Leal, Reference Leal1991: 55; Rios, Reference Rios1994: 40, pl. 12, fig. 131; Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009: 147; Rios, Reference Rios2009: 64 (text fig. in error); Gondim et al., Reference Gondim, Dias, Campos, Alonso and Christoffersen2011: 78, tab. 1.

Distribution: Previously known from northeastern Brazil, from Alagoas to southern Bahia states, including oceanic islands (Leal, Reference Leal1991; Rios, Reference Rios1994); expanded herein north-eastward to Canopus, off the state of Ceará.

Habitat: Benthos, biogenic sediment, 52–120 m (live specimens) to 240–260 m (empty shells only).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 60–70 m, MZSP 67312, 1 sh (viii/2005), MZSP 70326, 1 sh (viii/2005), MZSP 70366, 1 sh (viii/2005); 240–260 m, MZSP 131038, 8 sh (viii/2005), MZSP 170752, 3 sh (viii/2005). Additional material: Holotype USNM 214135, Brazil, Paraíba, off João Pessoa, SE of Cape Roque, R/V Albatross sta. 2758, 37 m (16/xii/1887). BRAZIL; Bahia: off Alcobaça, Minerva Bank, 17°01′S, 37°37′W, 120 m, MZSP 107929, 100 spm (Abbate and Lima col., 12/viii/2012).

Measurements (in mm; n = 5): 4¼ whorls, H = 4.5 ± 0.4, D = 5.2 ± 0.3.

Remarks: This species is characterised by its small, trochoid-turbiniform shell (H = ∼5 mm), a channelled suture, and a variable colour pattern ranging from uniform dark brown to dark red, often with axial bands or irregular markings of differing intensity on an otherwise white to cream background. The sculpture, consisting of three prominent spiral cords bearing nodules and axial growth lines that are more pronounced in the interspaces, is also diagnostic. Considerable intraspecific variation occurs in shell proportions, number of sculpture elements, and colouration. Each whorl invariably bears three dominant spiral cords, which may be robust and separated by deep interspaces (Figure 13J) or weaker with shallower interspaces, producing a smoother profile (Figure 13L), with a continuum of intermediate conditions. The shell outline can be rounded (Figure 13D, L) or keeled (Figure 13K), depending on the prominence of the dominant cords. The nodules likewise range from angular (Figure 13E) to rounded and less conspicuous (Figure 13H).

Dall (Reference Dall1927: 4) originally described the species as ‘white, with radiating blotches of rose pink’, but the present material demonstrates a much broader colour spectrum, ranging from reddish to dark brown. Some specimens exhibit a mixture of reddish and brown tones (Figure 13E). This variability, already noted in detail by Leal (Reference Leal1991), is also displayed by the Minerva Bank specimens from southern Bahia examined herein. The Canopus material, though scarce, damaged, and predominantly brown, includes individuals that are mostly brown-white with faint red markings (Figure 13E). The record from Canopus extends the species’ known range by ∼800 km north-eastward, from Alagoas (10°S) to Ceará (2°S), while live specimens from Minerva Bank increase the maximum recorded depth from 81 m (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009) to 120 m.

Arene flexispina Leal & Coelho, 1985

(Figure 14)

Figure 14.

Arene flexispina: (A) Holotype MNRJ 5352, from Bahia, apertural view (H = 6.3 mm, D = 6.0 mm), modified from Pimenta et al. (Reference Pimenta, Monteiro, Barbosa, Salgado and Coelho2014); (B–F) MZSP 170753, from Canopus; (B) apertural view (H = 6.0 mm, D = 5.0 mm); (C) apical view; (D) abapertural view; (E) umbilical view; (F) detail of apex. (G–H) MZSP 122851: (G) apertural view (H = 7.5 mm, D = 6.4 mm); (H) apical view; (I) MZSP 122851, juvenile specimen, apertural view (H = 3.9 mm, D = 4.6 mm); (J) MZSP 110862, from Minerva Bank, apertural view (H = 7.5 mm, D = 6.8 mm).

Synonymy see Leal (Reference Leal1991). Complement:

Arene flexispina: Leal, Reference Leal1991: 54, pl. 1, fig. F, pl. 4, figs. E–F; Rios, Reference Rios1994: 40, pl. 12, fig. 133; Reference Rios2009: 64, text fig.; Pimenta et al., Reference Pimenta, Monteiro, Barbosa, Salgado and Coelho2014: 64, fig. 4a–c.

Distribution: Previously known from northeastern to southeastern Brazil, from the states of Bahia to Espírito Santo (Leal, Reference Leal1991); expanded herein northward to Canopus, off the state of Ceará.

Habitat: Coralline bottoms, 54–780 m (Leal, Reference Leal1991; present study).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 122851, 4 sh, MZSP 170753, 1 sh. Additional material: Holotype MNRJ 5352, Brazil, Bahia, 40 km off Ponta de Corumbaú, GEOMAR X sta. 48, 16°56′30″S, 38°39′30″W, 80 m (R/V Almirante Câmara col., 09/vi/1978). Paratypes: USNM 820786, 1 sh, USNM 820786A, 1sh, MNRJ 5353, 1 sh, MORG 22807, 1 sh, MORG 22808, 1 sh, all from the type locality; MORG 22619, Brazil, Espírito Santo, off Conceicção da Barra, GEOMAR X sta. 38, 18°49′S, 37°52′W, 54 m, 1 sh (R/V Almirante Câmara col., 07/vi/1978); MNRJ 5354, Brazil, Bahia, 120 km off Abrolhos Reef, GEOMAR X sta. 47, 16°44′S, 37°21′W, 54 m (R/V Almirante Câmara col., 08/vi/1978). BRAZIL; Bahia: Minerva Bank, 17°06′S, 37°38′W, 120 m, MZSP 110862, 30 sh + 5 spm (Abbate and Lima col., 2013).

Measurements (in mm): Largest specimen (MZSP 122851), 4½ whorls, H = 8.5, D = 7.0.

Remarks: This species was originally described from Bahia state, northeastern Brazil, and was subsequently recorded in the Vitória–Trindade Seamount Chain, off Espírito Santo, based on specimens collected during the Marion Dufresne MD55 expedition (Leal, Reference Leal1991). Most adult specimens in the Canopus assemblage are heavily worn (Figure 14G, H), but their shell outline and faint residual colouration allowed for reliable identification. A well-preserved specimen illustrated herein (Figure 14B–F) displays the diagnostic features of the species, including a white protoconch and teleoconch sculpture of spiral cords bearing large, recurved spines, combined with the characteristic reddish and yellowish-green colour pattern. The juvenile specimen examined (Figure 14I) also differs markedly from juveniles of similar local congeners in both colour and sculpture. Furthermore, the overall outline of adult specimens from Canopus (Figure 14G) closely matches that of adult individuals from Minerva Bank (Figure 14J), a region relatively near the type locality. The Minerva Bank material also suggests that most shells of A. flexispina illustrated to date, including the holotype (Figure 14A), may be subadult specimens.

Some specimens of A. flexispina examined herein exceed the size originally reported by Leal and Coelho (Reference Leal and Coelho1985), who recorded a shell height of 6.4 mm and a diameter of 6.7 mm. The largest specimen studied (MZSP 122851) reaches 7.9 mm in height and 6.7 mm in diameter, appearing to have grown an extra half whorl. Beyond intraspecific variation, this additional whorl likely accounts for the altered height-to-diameter ratio, as larger, older shells are slightly taller than wide. Leal and Coelho (Reference Leal and Coelho1985) also noted that shell height proportionally increases with age, a pattern confirmed here. The umbilicus, initially described as wide and deep, appears to narrow and may even become imperforate in larger specimens (Figure 14G, J). The larger shell size of A. flexispina distinguishes it from most local congeners, except for A. lychee (see below), from which it differs by its distinct colouration, proportionally taller shell with a more inflated base, spiral cords bearing fewer but larger spines, narrower interspaces between cords, and a subtly coloured apex. The Canopus records (2°S) extend the species’ known distribution by approximately 1,600 km northward, far beyond the previously reported range from Bahia (12°30′S) to Espírito Santo, while the bathymetric range (54–780 m) remains consistent with previously known depths.

Arene lychee Cavallari & Simone, 2018

(Figure 15)

Figure 15.

Arene lychee from Canopus Bank: (A–D) Holotype MZSP 70301: (A) apertural view (H = 8.3 mm, D = 7.5 mm); (B) apical view; (C) umbilical view; (D) Paratype MZSP 135314, juvenile specimen, apertural view (H = 3.6 mm, D = 4.7 mm); (E) Paratype MZSP 135314, apertural view (H = 7.2 mm, D = 6.5 mm); (F) Holotype, detail of the apex.

Arene lychee Cavallari and Simone, 2018: 1, fig. 1A–H.

Distribution: Known only from the type locality at Canopus Bank.

Habitat: Benthos, biogenic sediment, at 200–260 m.

Material examined: Holotype MZSP 70301, Brazil, Ceará, off Fortaleza, Canopus Bank, 02°14′25″S, 38°22′50″W, 260 m. Paratypes: MZSP 93482, 2 juv. sh, MZSP 93501, 2 sh, MZSP 135314, 4 shells, all from the type locality, 200 m depth (viii/2005).

Measurements (in mm): Holotype 5½ whorls, H = 8.3, D = 7.5.

Remarks: This species more closely resembles Arene briareus (Dall, Reference Dall1881) and A. bairdii (Dall, Reference Dall1889) from the Caribbean and Western Atlantic, in both colour pattern and size. Arene lychee differs from both by its proportionally taller, trochoid shell (Figure 15A, E) with a straighter profile and one less spiral cord per whorl. It also bears much larger, coarser, and more pronounced nodules/spines (Figure 15C). Moreover, it can be distinguished from nearly every other congener in Brazilian waters by the size alone, being at least 25% larger than the remaining species, except for A. flexispina. From the latter, it differs by its colour pattern, a predominantly red shell with a yellow apex (Figure 15F), as opposed to a red-green shell with a white apex in A. flexispina (Figure 14A–J), by the more numerous nodules/spines (Figure 15B), being proportionally shorter and wider, and by having a less convex and more coarsely sculptured base (Figure 15F).

Family Calliostomatidae Thiele, 1924

General remarks: Calliostomatidae is a diverse family of trochiform snails that includes over 30 genera and 300 species of widely variable size (8–100 mm). They can be found in all oceans, ranging from tropical to polar latitudes, from intertidal to bathyal (3,000 m) depths, on soft or, more commonly, rocky substrata (Marshall, Reference Marshall and Bouchet1995, Reference Marshall2016; Williams et al., Reference Williams, Donald, Spencer and Nakano2010). Morphologically, Calliostomatids are characterised by the typical depressed-conical shell outline and, concerning trochids, by the protoconch sculpture and radular features (Hickman and McLean, Reference Hickman and McLean1990; Marshall, Reference Marshall and Bouchet1995). Several species in this family are carnivorous, feeding on cnidarians, sponges, epibionts living on hard substrates, carrion, and possibly even smaller molluscs (Williams et al., Reference Williams, Donald, Spencer and Nakano2010; Dornellas and Simone, Reference Dornellas and Simone2011b; Hoffman et al., Reference Hoffman, Beuck, van Heugten, Lavaleye and Freiwald2019). Calliostomatidae has been included in broader molecular systematics studies on Trochoidea (Williams et al., Reference Williams, Karube and Ozawa2008; Williams, Reference Williams2012), and relationships within the family have also been investigated based on molecular data (Williams et al., Reference Williams, Donald, Spencer and Nakano2010). These studies have so far corroborated the familial status of the taxon, as opposed to previous hypotheses that considered it a subfamily of Trochidae Rafinesque, 1815 (Hickman and McLean, Reference Hickman and McLean1990). It currently includes three subfamilies: Calliostomatinae Thiele, Reference Thiele1924; Margarellinae Williams, 2013; and Thysanodontinae Marshall, Reference Marshall1988 (Williams, Reference Williams2012, Reference Williams2013). Two additional subfamilies, Fautricinae Marshall, Reference Marshall and Bouchet1995, and Xeniostomatinae McLean, 2012, were proposed based on morphological data (McLean, Reference McLean2012a; Marshall, Reference Marshall2016), but their monophyly and relationships have not yet been investigated. The genus Calliostoma Swainson, 1840, within Calliostomatinae, is the largest of the family, comprising over 200 species, 23 of which occur in Brazilian waters (Costa et al., Reference Costa, Pimenta and Dornellas2025).

Genus Calliostoma Swainson, 1840

Synonymy see Clench and Turner (Reference Clench and Turner1960: 11) and Marshall (Reference Marshall and Bouchet1995: 387).

Type species: Trochus conulus Linnaeus, 1758, by subsequent designation (Herrmannsen, Reference Herrmannsen1846); Recent, Northeast Atlantic and Mediterranean.

Calliostoma hassler Clench & Aguayo, 1939

(Figure 16A–I)

Figure 16.

Calliostoma from Canopus: (A–I) Calliostoma hassler: (A) Holotype MCZ 104554, from Cabo Frio, apertural view (H = 42 mm, D = 35 mm; photo is a courtesy of the MCZ); (B–D) MZSP 67311 from Canopus; (B) apical view (D = 7.2 mm); (C) apertural view (H = 6.0 mm); (D) lateral view; (E–H) same, spm. #2: (E) apertural view (H = 5.8 mm, D = 6.7 mm); (F) lateral view; (G) apical view; (H) umbilical view; (I) same, spm. #3, juvenile, apertural view (H = 3.8 mm, D = 4.6 mm). (J–K) Calliostoma melliferum: (J) Holotype MZSP 53718, from Canopus Bank, apertural view (H = 7.42 mm); (K) Paratype MZSP 67310, apertural view (H = 9.58 mm, D = 8.13 mm).

Synonymy see Dornellas and Simone (Reference Dornellas and Simone2013). Complement:

Calliostoma hassler: Abbott, Reference Abbott1974: 46; Dornellas, Reference Dornellas2012: 104, figs. 13–15; Dornellas and Simone, Reference Dornellas and Simone2013: 285, figs. 24–25, 44, 51–53, 91–98; Pádua et al., Reference Pádua, Silva and Duarte2019: 112; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021: 77, figs. A–C.

Astele (Leiotrochus) hassler: Macsotay and Campos, Reference Macsotay and Campos2001: 35, pl. 13, figs. 9–10.

Distribution: From northern Venezuela (Paria) to São Paulo state in southeastern Brazil (Macsotay and Campos, Reference Macsotay and Campos2001; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021).

Habitat: Coralline and sandy bottoms, 40–65 m (Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 60 m, MZSP 67311, 6 sh (viii/2005). Additional material: Holotype MCZ 104554, Brazil, off Cabo Frio, 75 miles east of Rio de Janeiro, 35 fathoms (20/ii/1872). Paratype MCZ 104555, 1 sh; MPUH (Cuba), 1 sh; same data as holotype.

Measurements (in mm): Largest specimen, ∼6 whorls, H = 6.0, D = 7.2.

Remarks: Although the specimens from Canopus Bank are juveniles (Figure 16B–I), they correspond well with the initial whorls of the type material and with the characters and specimens illustrated by Dornellas and Simone (Reference Dornellas and Simone2013: figs. 24–35). This is particularly true for the holotype of Calliostoma vinosum Quinn, Reference Quinn1992, which has been regarded as a juvenile specimen and a junior synonym of C. hassler (Dornellas and Simone, Reference Dornellas and Simone2013: figs. 26–27). Dornellas and Simone (Reference Dornellas and Simone2013) also provided a comprehensive comparison of southwestern Atlantic Calliostoma species, based on an extensive analysis of conchological and soft-part characters. Clench and Aguayo (Reference Clench and Aguayo1939) highlighted the yellowish hue of the type specimens, attributing it to possible colour loss after prolonged exposure to preservative fluids. However, the material examined herein, as well as that illustrated by Dornellas and Simone (Reference Dornellas and Simone2013), indicates otherwise: the variation from yellowish (Figure 16A–D) to vivid red (Figure 16E–I) appears to represent the natural ground-colour range of the species. Longo et al. (Reference Longo, Fernandes, Leite and Passos2014) figured an unidentified Calliostoma specimen from São Paulo state, Brazil, that closely matches the C. hassler juveniles reported herein in outline, sculpture, and colour pattern, and likely belongs to this species. In any case, Canopus lies well within the known distribution of C. hassler, which extends from northern Venezuela to southeastern Brazil (Macsotay and Campos, Reference Macsotay and Campos2001) and also within its known bathymetric range (40–65 m; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021).

Calliostoma melliferum Cavallari & Simone, 2018

(Figure 16J, K)

Calliostoma melliferum Cavallari and Simone, Reference Cavallari and Simone2018b: 157, figs. 1–33.

Distribution: Known only from the type locality at Canopus Bank.

Habitat: Benthos, biogenic sediment, from 60 m (live specimens) to 260 m (empty shells).

Measurements (in mm; n = 10): ∼7 whorls, H = 8.0 ± 0.8, D = 7.0 ± 0.7.

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 170757, 26 sh + fragments (viii/2005). Additional material: Holotype MZSP 53718, Brazil, Ceará, 190 km off Fortaleza, Canopus Bank, 02°14′25″S, 38°22′50″W, 60 m (Coltro and Costa col., viii/2005). Paratypes: MZSP 53923, 1 spm (viii/2005); MZSP 53693, 5 spm (viii/2005); MZSP 53711, 2 sh (viii/2005); MZSP 55522, 1 spm (viii/2005), all from the type locality; same locality data, 240–260 m, MZSP 53939, 2 sh (viii/2005); MZSP 66589, 1 sh (viii/2005); MZSP 67310, 6 sh (xi/2005); MZSP 70308, 70 sh (xi/2005); MZSP 71960, 1 sh (viii/2005); MZSP 71961, 1 sh (xi/2005); MZSP 90268, 150 sh (xi/2005); MZSP 94218, 27 sh (xi/2005); MZSP 94254, 13 sh (xi/2005); MZSP 94837, 1 sh (xi/2005); MZSP 100414, 6 sh (xi/2005).

Remarks: This species is highly abundant locally and is readily distinguishable from any other calliostomatid occurring in Caribbean or Brazilian waters. It can be separated from nearly all southwestern Atlantic Calliostoma by its smaller size, large and rounded apex (Figure 16J, K), deep suture, markedly convex whorls, characteristic ivory-white background colouration with a honey-yellow apex and spiral cords, often displaying a nacreous sheen, smooth base, and an ovate, laterally displaced aperture. Among local species of comparable size, it differs from C. depictum Dall, Reference Dall1927; C. coppingeri (Smith, 1880); and C. rota Quinn, Reference Quinn1992, by its proportionally taller shell, less convex whorls, stronger overall sculpture, and predominantly smooth base; it also lacks the distinct median carina present in C. coppingeri and C. rota. It can further be distinguished from C. caribbechinatum Landau, Van Dingenen and Ceulemans, 2017, and C. brunneopictum Quinn, Reference Quinn1992, by its taller shell with more inflated whorls and base, larger but fewer axial and spiral elements, and by having a perforate umbilicus.

Family Colloniidae Cossmann, 1917

General remarks: Shell features such as the absence of nacre, aperture outline, and calcified operculum were widely used to characterise the Colloniidae, though some of these features vary considerably (McLean, Reference McLean2012b). Because of shell similarities and the calcified operculum, Colloniidae was considered a subfamily of Turbinidae (Williams et al., Reference Williams, Karube and Ozawa2008). The oldest fossil record of the family dates from the Jurassic (Monari et al., Reference Monari, Conti, Szabo and Taylor1996) and possibly even earlier, since similar operculae have been found in Cretaceous formations (McLean, Reference McLean2012b). The family currently includes 19 genera (Bouchet and Gofas, Reference Bouchet and Gofas2011), of which only Homalopoma Carpenter, 1864, occurs in Brazilian waters.

Genus Homalopoma Carpenter, 1864

Homalopoma Carpenter, Reference Carpenter1864a: 537.

Leptonyx Carpenter, Reference Carpenter1864a: 652 (objective synonym, preoccupied name).

Leptothyra Cooper, Reference Cooper1867: 25 (objective synonym).

Type species: Turbo sanguineus Linnaeus, 1758, by monotypy; Recent, northeastern Atlantic and Mediterranean.

Homalopoma boffii Marini, 1975

(Figures 17, 18)

Figure 17.

Homalopoma boffii: (A–E) Holotype MZSP 18772, from Rio Grande do Sul; (A) apical view (D = 6.98 mm); (B) umbilical view; (C) protoconch detail; (D) apertural view (H = 6.27 mm); (E) abapertural view. (F) Paratype MZSP 18773, apertural view (H = 6.08 mm, D = 6.9 mm). (G–M) MZSP 93535, from Canopus: (G–I) Orange-coloured specimen; (G) apical view (D = 7.79 mm); (H) umbilical view; (I) apertural view (H = 7.28 mm); (J) protoconch detail under SEM; (K) cream-coloured specimen, apertural view (H = 8.25 mm, D = 8.09 mm); (L–M) operculum: (L) inner surface (D = 1.2 mm); (M) outer surface.

Figure 18.

Records of Homalopoma boffii along the Brazilian coastline: (1) Canopus Bank; (2) off Espírito Santo, MD55 sta. DC73; (3) off Santos; (4) off Rio Grande do Sul state, type locality. Abbreviations: CE: Ceará state; ES: Espírito Santo state; SP: São Paulo state; RS: Rio Grande do Sul state.

Figure 18 Long description

The Brazilian coastline with four marked locations: (1) Canopus Bank near Ceara state, (2) off Espirito Santo, (3) off Santos in Sao Paulo state and (4) off Rio Grande do Sul state. An inset map of South America highlights Brazil. The map includes a compass rose indicating north, east, south and west and a scale bar showing 0 to 400 kilometers. Abbreviations for states are CE for Ceara, ES for Espirito Santo, SP for Sao Paulo and RS for Rio Grande do Sul. The Atlantic Ocean is labeled to the east of Brazil.

Homalopoma boffii Marini, Reference Marini1975: 31, figs. 1–3. Rios, Reference Rios1985: 26, pl. 11, fig. 109, Reference Rios1994: 43, pl. 14, fig. 145, Reference Rios2009: 69, textfig. (switched with the preceding entry in error).

Homalopoma boffi [sic]: Leal, Reference Leal1991: 58; Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009: 151.

Homalopoma bofii [sic]: Dornellas and Simone, Reference Dornellas and Simone2011a: 7, figs. 32–34.

Distribution: Brazil, from Espírito Santo to Rio Grande do Sul states, including oceanic islands such as Trindade and Martim Vaz, and seamounts Montague and Columbia (Leal, Reference Leal1991; Rios, Reference Rios1994); expanded herein to northeastern Brazil, off the state of Ceará (Figure 18).

Habitat: Benthos, biogenic bottoms, 60–780 m.

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 60–200 m, MZSP 93535, 27 sh + operculum (viii/2005); 240–260 m, MZSP 53938, 2 sh (viii/2005), MZSP 170754, 4 sh; 260 m, MZSP 67303, 7 sh (xi/2005), MZSP 70298, 4 sh (xi/2005). Additional material: Holotype MZSP 18772, Brazil, off Rio Grande do Sul state, 31°08′S, 49°31′W, 183–253 m, R/V ‘W. Besnard’ sta. 1858 (6/viii/1972); Paratype MZSP 18773, 1 spm, same data as holotype. BRAZIL; Espírito Santo: off São Mateus, Abrolhos Slope, MD55 sta. DC73, 18°59′05″S, 37°48′02″W, 607–620 m, MNHN, 1 sh (27/v/1987); São Paulo: off Santos, MZSP 36037, 2 sh (local fishermen col., xii/2002).

Measurements (in mm; n = 3): 6 whorls, H = 8.8 ± 1.2, D = 9.0 ± 1.4.

Remarks: This species appears to be particularly abundant at Canopus Bank and is typically characterised by its reddish colouration, large shell with strong, rounded spiral cords, and coarse nodulose sculpture beginning on the initial teleoconch whorls but usually restricted to the first 3–4 whorls (Marini, Reference Marini1975). The Canopus specimens correspond closely to the type material, differing only in a few aspects. Ground colouration is variable, ranging from cream (Figure 17K) to orange-reddish (Figure 17G–I), with intermediates: a degree of variation not previously reported in the literature. The characteristic white spots described by Marini (Reference Marini1975) are present in all examined specimens, though with variable intensity. Shells from Canopus are slightly taller (Figure 17I, K), likely due to the specimens being older than the subadult types, bearing an additional ½ teleoconch whorl. A similar difference in outline is observed in specimens from São Paulo state examined herein. Furthermore, the species attains a larger size than previously reported (H = 6.9 mm, D = 7.0 mm; Marini, Reference Marini1975; Rios, Reference Rios1994, Reference Rios2009), reaching up to 10.9 mm in height (MZSP 67303) and 10.8 mm in diameter (MZSP 36037) in the Canopus assemblage.

Leal (Reference Leal1991) suggested that the figures in Marini’s (Reference Marini1975: figs. 1–3) original description had been inadvertently switched with those of another species. However, our examination of the type material confirms that the proportions, sculpture, and even the position of damaged areas in the figured specimen correspond precisely to the holotype (MZSP 18772; Figure 17A–E). Both type specimens are subadult shells (Figure 17A–F), and the subtle changes in outline associated with growth may have led to this earlier misinterpretation.

Marini (Reference Marini1975) had already noted the similarity between H. boffii and H. linnei, attributing their distinction primarily to ground colour (reddish in H. boffii vs. pure white in H. linnei), number of spiral cords (fewer in H. linnei), and size (∼25% larger in H. boffii). While the size difference is corroborated, and even more pronounced in the material examined herein, the other proposed differences are not supported: some H. boffii specimens from Canopus are nearly pure white (Figure 17K), and the number of spiral cords on the body whorl varies from 12 to 16 in both species. Nonetheless, additional distinguishing features are evident (see the remarks on H. linnei, below).

Previously considered restricted to southern and southeastern Brazilian waters (around 21°S; Leal, Reference Leal1991; Rios, Reference Rios1994, Reference Rios2009), H. boffii is here shown to have a much broader distribution, extending ca. 2,000 km as far north as northeastern Brazil (2°S; Figure 18). Part of its range overlaps with that of H. linnei (Dall, Reference Dall1889), which also occurs in Canopus and other localities along and off the southeastern Brazilian coast (Cavallari et al., Reference Cavallari, Salvador, Dornellas and Simone2019; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021).

Homalopoma linnei (Dall, 1889)

(Figures 19–21)

Figure 19.

Homalopoma linnei: (A–F) Syntypes USNM 94985 from St. Lucia; (A) umbilical view (D = 3.7 mm); (B) apical view; (C) apertural view (H = 4.1 mm); (D–F) specimen #2: (D) umbilical view (D = 5.0 mm); (E) apical view; (F) apertural, slightly lateral view (H = 5.5 mm). (G–M) specimens from Canopus Bank: (G) MZSP 53726, apertural view (H = 6.2 mm, D = 5.0 mm); (H) MZSP 70295, apertural view (H = 5.3 mm, D = 4.7 mm); (I) same, specimen #2, apertural view (H = 5.7 mm, D = 4.8 mm); (J) umbilical view; (K) apical view; (L) operculum, inner surface (L = 1.5 mm); (M) same, outer surface. Type photos by Barbara V. Romera.

Synonymy see Cavallari et al. (Reference Cavallari, Salvador, Dornellas and Simone2019). Complement:

Homalopoma linnei: Cavallari et al., Reference Cavallari, Salvador, Dornellas and Simone2019: 413, fig. 5D–J; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021: 88, figs. A–C.

Distribution: Previously known from Florida, USA, to Brazil (Miyaji, Reference Miyaji, Amaral and Rossi-Wongtschowski2004; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009); in Brazil from Espírito Santo to São Paulo, including the Vitória–Trindade Seamount Chain (Cavallari et al., Reference Cavallari, Salvador, Dornellas and Simone2019; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021); expanded herein to northeastern Brazil, off the state of Ceará (Figure 21).

Habitat: Benthos, coralline bottoms and biogenic sediment, 40–1,472 m (Cavallari et al., Reference Cavallari, Salvador, Dornellas and Simone2019; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021; present study).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 60–260 m, MZSP 53726, 24 sh (viii/2005); 240–260 m, MZSP 55524, 2 spm (xi/2005), MZSP 170755, 3 sh (viii/2005); 260 m, MZSP 67309, 5 sh (viii/2005), MZSP 70295, 3 sh + 4 spm (xi/2005), MZSP 94229, 4 sh (xi/2005). Additional material: Syntype MCZ 7538, Cuba, Havana, off Morro Light, Blake sta. 02, 23°14′N, 82°25′W, 1,472 m, 1 sh (R/V Blake col., 1877); Syntype MCZ 7539, Cuba, off Havana, 822 m, 1 sh (R/V Blake col., 1877); Syntype MCZ 7540, Cuba, off Honda Bay, 23°2′30″ N, 83°11′0″W, 402 m, 1 sh (R/V Blake col., i/1878); Syntype NMNH 94984, Caribbean Sea, Barbados, 13°17′N, 59°53′W, 183 m, 5 sh (R/V Blake col.); Syntype NMNH 94985, Caribbean Sea, St. Lucia, Blake sta. 220, 13.8375 N, 61.0625 W, 212 m, 1 sh (R/V Blake col., 16/ii/1879); BRAZIL; Espírito Santo: off São Mateus, Abrolhos Slope, MD55, sta. DC73, 18°59′05″S, 37°48′02″W, 607–620 m, MNHN, 4 sh (Bouchet, Leal and Métivier col., 27/v/1987); MD55, sta. CB77, 19°40′S, 37°48′W, 790–940 m, MNHN, 1 sh (Bouchet, Leal and Métivier col., 27/v/1987).

Measurements (in mm): Largest specimen (MZSP 53726), 6 whorls, H = 6.3, D = 5.0.

Remarks: In the original description, Dall (Reference Dall1889) cited fig. 9 on plate 33; however, that figure corresponds to another taxon described in the same work (A. bairdii, p. 389). The correct illustration is fig. 8, which matches both the original description and the types examined herein (Figures 19A–F, 20H). This error likely resulted from a typographical mistake during the final printing, as evidenced by the disruption in the numerical sequence of figures. The specimens analysed in this study correspond closely to the original description and examined syntypes in terms of size, sculpture, and variation. Nevertheless, most shells examined herein exhibit spiral cords with spiny nodules on nearly all whorls, producing a markedly rougher, ‘spiky’ appearance. Although Dall (Reference Dall1889) acknowledged this variant as rare, probably referring to one of the syntypes figured herein (UNSM 94984, Figure 20H), our material indicates that such morphology is more frequent than previously recognised, particularly in the Canopus assemblage. Leal (Reference Leal1991) interpreted this variant as potentially representing a distinct species based on MD55 material, provisionally referring to it as ‘Homalopoma sp. 1’.

Figure 20.

Homalopoma linnei: (A–D) MZSP 70295 from Canopus Bank: (A) detail of body whorl showcasing scale-like nodules; (B) apical view under SEM; (C) aperture with operculum; (D) protoconch; (E–G) same, under SEM: (E) apertural view (H = 4.9 mm, D = 4.6 mm); (F) apical view; (G) detail of body whorl under SEM showing scaly appearance given by the overlapping nodules; (H) Syntype USNM 94985 from St. Lucia, specimen #3, apertural view (H = 4.8 mm, D = 4.4 mm), photo by Bárbara V. Romera.

This species resembles the sympatric congener H. boffii, but can be distinguished by its markedly smaller size (approximately half as large), consistently cream to white colouration, and denser sculpture. The spiral cords (‘costae’ in Dall’s original 1889 description) are comparatively narrower, and while the number of cords per whorl varies and overlaps in both species, the nodules of H. linnei are more irregular, angular (spiny), smaller, and more numerous (Figure 20A). These nodules are also more closely packed, frequently becoming hollow and overlapping, producing a distinctive scaly appearance (Figure 20A, G), in contrast to the rounded, solid nodules of H. boffii. Additional diagnostic features include a more prominent, smoother, and inflated protoconch (Figure 20B, D) and the absence of the large, sequential nodules on the earliest teleoconch whorls that characterise H. boffii (Figure 20B). Furthermore, H. linnei exhibits a deep, well-defined subsutural channel, especially conspicuous in the Canopus specimens (Figures 19G–I, 20C), whereas this feature is less pronounced in H. boffii. The operculum also differs, bearing 9–10 whorls (Figure 19L, M) compared to 10–12 in H. boffii. These consistent distinctions, corroborated by examination of type material, strongly support the recognition of H. linnei as a valid, separate species.

The distribution of H. linnei in Brazil was previously restricted to sites along and off southeastern waters (Cavallari et al., Reference Cavallari, Salvador, Dornellas and Simone2019; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021). Much like its congener H. boffii, the species’ range is here extended 2,000 km northward to northeastern Brazil (2°S; Figure 21). This new record helps bridge its formerly disjunct distribution between the Caribbean and the Southwestern Atlantic, confirming H. linnei as a widespread species, although it is not regarded as particularly common (Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021).

Figure 21.

Records of Homalopoma linnei along the Brazilian coastline: (1) Canopus Bank; (2) off Espírito Santo, MD55 sta. DC73; (3) Same, sta. CB77. Abbreviations: CE: Ceará state; ES: Espírito Santo state.

Family Liotiidae Gray, 1850

General remarks: Liotiids are small snails (H ≤ 10 mm) characterised by shells with axial lamellae, a thickened lip, a calcified periostracum, and other distinctive conchological features (Hickman, Reference Hickman1988). The fossil record of the family extends back to the Permian. Liotiidae was traditionally treated as a subfamily of Turbinidae (Hickman and McLean, Reference Hickman and McLean1990), though some authors, such as Laseron (Reference Laseron1954), treated it at family rank. Bouchet et al. (Reference Bouchet, Rocroi, Fryda, Hausdorf, Ponder, Valdés and Warén2005) and Williams et al. (Reference Williams, Karube and Ozawa2008) subsequently elevated Liotiidae to family level, with the latter study providing molecular evidence. Williams et al.’s (Reference Williams, Karube and Ozawa2008) concept of the family excludes taxa later assigned to the newly established Areneidae McLean, 2012. The familial status of Liotiidae has been corroborated by subsequent molecular analyses (Williams, Reference Williams2012), but details of its biology and morphology, as currently defined, remain poorly understood. The family currently comprises 16 genera, of which only 2, Cyclostrema and Macrarene, and 3 species (Cyclostrema tortuganum, C. cancellatum, and Macrarene digitata) are known from Brazil (Cavallari et al., Reference Cavallari, Costa, Dornellas, Pimenta and Salvador2025).

Genus Macrarene Hertlein & Strong, 1951

Macrarene Hertlein and Strong, Reference Hertlein and Strong1951: 110.

Type species: Liotia californica Dall, 1908, by original designation; Recent, Pacific.

Macrarene digitata McLean, Absalão & Cruz, 1988

(Figure 22)

Figure 22.

Macrarene digitata from Canopus Bank: (A–C) MZSP 170758, spm. #1; (A) apertural view (H = 4.9 mm, D = 5.6 mm); (B) apical view; (C) umbilical view; (D) MZSP 131287, spm. #1 (subadult), apertural view (H = 2.4 mm, D = 4.3 mm); (E–J) MZSP 170758, spm. #1, 3D reconstruction of shell through CT (voxel size = 6.2 μm); (E) abapertural view; (F) lateral view; (G) umbilical view; (H) apical view; (I) apertural view, cross-section showing extent of umbilicus; (J) detail of apex showing the protoconch (arrow indicates transition).

Synonymy see Leal (Reference Leal1991). Complement:

Macrarene digitata: Leal, Reference Leal1991: 57; Mello and Barros, Reference Mello and Barros1991: 281, figs. 2, 4; Rios, Reference Rios1994: 41, pl. 13, fig. 138; Reference Rios2009: 66, text fig.; Farrapeira, Reference Farrapeira2011: appendix 1; Oliveira et al., Reference Oliveira, Pimenta, Figueira and Absalão2018: 100.

Distribution: North-northeastern Brazilian waters, from Amapá to Alagoas states (Mello and Barros, Reference Mello and Barros1991; Oliveira et al., Reference Oliveira, Pimenta, Figueira and Absalão2018).

Habitat: Benthos, biogenic sediment, from 0 to 260 m.

Material examined: Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 131287, 4 sh (viii/2005), MZSP 170758, 3 sh (viii/2005). Additional material: Holotype IBUFRJ 1562, off NE Brazil, 03°59′N, 49°35′W, 100 m (06/v/1968). Paratype LACM 2377, Brazil, Rio Grande do Norte state, off Cabo São Roque, 04°30′S, 50°03′W, 146 m, R/V Almirante Saldanha sta. 1921, 1 sh (8/v/1968). BRAZIL; Maranhão: off Maranhão, R/V Amorim do Valle, MZSP 94341, 1 sh.

Measurements (in mm): Largest specimen (MZSP 170758), 4¼ whorls, H = 4.9, D = 5.6.

Remarks: This seemingly rare species is among the least abundant in Canopus. Despite the low resolution and poor quality of previous illustrations in the literature, it can be readily identified. The shell is small (up to 6.7 mm), ivory-coloured, and displays a distinctive coiling pattern that gives it a flat-topped profile (Figure 22A, F). It is densely marked by fine axial growth lines (Figure 22E–G) and ornamented with a prominent sculpture of digitate, adapically upturned, scaly axial lamellae (Figure 22E–H), which are particularly pronounced along the outer lip (Figure 22A). These are intersected by thinner but well-defined spiral cords (Figure 22E, F, H). The protoconch consists of a single, glossy, mostly smooth whorl, with the transition to the teleoconch marked by a slight apertural (axial) thickening and an abrupt onset of sculpture (Figure 22J). The umbilicus is relatively narrow, slightly less than 20% of the shell diameter in adults, occasionally exceeding 30% in juveniles, but very deep, extending to the initial whorls (Figure 22I).

In the Canopus material, juvenile shells display a relatively flat spire (Figure 22D), which becomes taller as the specimen grows beyond 3¼ whorls (Figure 22A). Previous records list the species from off the northern Brazilian states of Pará and Maranhão southward to Rio Grande do Norte and Alagoas (Mello and Barros, Reference Mello and Barros1991; Rios, Reference Rios1994). However, as noted by Oliveira et al. (Reference Oliveira, Pimenta, Figueira and Absalão2018), the coordinates of the type locality and collection station actually correspond to off Amapá, in northern Brazil, warranting a reassessment of its distribution. The Canopus specimens, half of which are juveniles (Figure 22D–F), close the small gap in the species’ known range between Maranhão and Rio Grande do Norte and constitute its deepest records to date, extending the maximum depth from 146 m to the 240–260 m range.

Family Margaritesidae Thiele, 1924

General remarks: Formerly treated as a subfamily of Trochidae Rafinesque, 1815, Margaritesidae (then Margaritidae) was elevated to family rank by Williams (Reference Williams2012) based on molecular data. The name was originally introduced by Stoliczka (Reference Stoliczka1868), but her act is considered nomenclaturally invalid (Bouchet et al., Reference Bouchet, Rocroi, Fryda, Hausdorf, Ponder, Valdés and Warén2005); authorship is therefore attributed to Thiele (Reference Thiele1924), who first revised the group. Margaritesids possess small to moderately sized shells (rarely exceeding 20 mm in height) with a turbinoid to trochiform profile, smooth, rounded whorls, and frequently a nacreous sheen, although these features vary within the family. The familial name was recently emended to Margaritesidae due to the homonymy with the bivalve family Margaritidae Blainville, 1824 (Bieler and Bouchet, Reference Bieler and Bouchet2022). The group has a disjunct distribution, occurring from shallow to deep waters at both high and tropical latitudes. The oldest known margaritesid fossils are from Upper Eocene deposits (Hickman and McLean, Reference Hickman and McLean1990). Simone and Cunha (Reference Simone and Cunha2006) provided a comprehensive revision of the genera Gaza Watson, Reference Watson1879, and Callogaza Dall, Reference Dall1881, including Brazilian species, with additional notes on other local margaritesids.

Genus Callogaza Dall, 1881

Synonymy see Simone and Cunha (Reference Simone and Cunha2006: 20).

Type species: Callogaza watsoni Dall, Reference Dall1881, by subsequent designation (Clench and Abbott, Reference Clench and Abbott1943); Recent, Atlantic.

Callogaza watsoni Dall, 1881

(Figure 23)

Figure 23.

Callogaza watsoni: (A–C) Holotype MCZ 7544, from Cuba: (A) apertural view (H = 8 mm; D = 12.5 mm); (B) umbilical view; (C) apical view; photos are a courtesy of the MCZ. (D–F) MZSP 170759 from Canopus Bank: (D) apertural view (H = 4.2 mm, D = 5.9 mm); (E) umbilical view; (F) apical view. (G–I) MZSP 70320 from Canopus, juvenile specimen: (G) apertural view (H = 4.0 mm, D = 5.3 mm); (H) umbilical view; (I) apical view; (J–L) MZSP 70486 from Canopus, juvenile specimen: (J) apertural view (H = 3.6 mm, D = 4.7 mm); (K) umbilical view; (L) apical view.

Synonymy see Simone and Cunha (Reference Simone and Cunha2006). Complement:

Callogaza watsoni: Simone and Cunha, Reference Simone and Cunha2006: 22, figs. 41–44, 58–60; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009: 624.

Gaza (Callogaza) watsoni: Rios, Reference Rios2009: 55.

Distribution: From the Yucatan Strait to northeastern Brazil (Simone and Cunha, Reference Simone and Cunha2006).

Habitat: Benthos, biogenic sediment, from 66 to 1,170 m depth (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009; present study).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 200 m, MZSP 93487, 1 sh (viii/2005), MZSP 93498, 2 sh (viii/2005); 240–260 m, MZSP 170759, 1 sh; 260 m, MZSP 55529, 1 spm (xi/2005), MZSP 70320, 2 sh (xi/2005), MZSP 70486, 1 sh (viii/2005). Additional material: Holotype MCZ 7544, Blake Expedition (1877).

Measurements (in mm): Largest specimen (MZSP 170759), 5½ whorls, H = 4.2, D = 5.9.

Remarks: The specimens examined herein are juvenile to subadult individuals, ranging from 3¾ to 5½ whorls. Adult specimens, as described by Simone and Cunha (Reference Simone and Cunha2006), possess 7 whorls, a condition confirmed by the holotype (Figure 23A–C). The juveniles also lack the well-developed inner lip that partially covers the umbilicus, as well as the reflected peristome characteristic of adults (Figure 23D, G, J). Nevertheless, the largest individual (Figure 23D–F) closely matches the holotype in overall outline and colouration. All specimens exhibit the strongly defined reticulate sculpture on the apical side of the whorls (Figure 23F, I, L), a prominent spiral sculpture producing a distinctly keeled profile (Figure 23D, G, J), and a similarly sculptured periumbilical region (Figure 23E, H, K), marked by numerous axial furrows. Furthermore, several specimens examined herein are remarkably similar to the individual illustrated by Simone and Cunha (Reference Simone and Cunha2006: figs. 58–60), originally reported by Dall (Reference Dall1890: 342) as a record from Brazil. That specimen was also collected off Fortaleza, albeit from a different locality (R/V Albatross sta. 2756, 22°00′S 37°49′00″W, 716 m depth).

Family Phasianellidae Swainson, 1840

General remarks: Phasianellidae comprises small, shallow-water gastropods inhabiting tropical and subtropical seas worldwide. Their shells are rounded, globose, and porcelaneous, typically brightly coloured and patterned, and generally measure only a few millimetres in height and width. In the Western Atlantic, species range from 2 to 9 mm in shell height, although considerably larger species occur in the Australasian region. The operculum is paucispiral and calcareous (Robertson, Reference Robertson1958). Fossil records trace the family back to the Paleogene. Extant phasianellids are commonly associated with marine angiosperms and algae (Hickman and McLean, Reference Hickman and McLean1990). Historically treated as a subfamily of Turbinidae, Phasianellidae was elevated to family rank by Williams and Ozawa (Reference Williams and Ozawa2006) based on molecular evidence. Currently, three genera and five species are known from Brazil (Cavallari et al., Reference Cavallari, Costa, Dornellas, Pimenta and Salvador2024).

Genus Eulithidium Pilsbry, 1898

Eulithidium Pilsbry, Reference Pilsbry1898: 60.

Eucosmia Carpenter, Reference Carpenter1864b: 475 [non Stephens, 1831; replaced name].

Type species: Eucosmia variegata Carpenter, 1864, by monotypy; Recent, USA.

Eulithidium affine (Adams, 1850)

(Figure 24)

Figure 24.

Eulithidium affine MZSP 132136 from Canopus Bank: (A) apertural view (H = 2.4 mm, D = 1.7 mm); (B) abapertural view; (C) apical view; (D) protoconch detail; (E) spm. #2, apertural view (H = 2.3 mm, D = 1.7 mm).

Ancient synonymy see Robertson (Reference Robertson1958). Recent synonymy see Leal (Reference Leal1991). Complement:

Tricolia concinna: Morretes, Reference Morretes1949: 62.

Tricolia affinis: Poirier, Reference Poirier1954: 26; Warmke and Abbott, Reference Warmke and Abbott1961: 48, pl. 8, fig. I; Ekdale, Reference Ekdale1974: 642; Oliveira et al., Reference Oliveira, Rezende and Castro1981: 67; Vokes and Vokes, Reference Vokes and Vokes1983: 13, 50, pl. 23, fig. 11; Leal, Reference Leal1991: 61; Díaz and Puyana, Reference Díaz and Puyana1994: 120, pl. 37, fig. 379; González, Reference González1998: 626; Paranaguá et al., Reference Paranaguá, Neumann-leitão, Melo, Coelho, Vasconcelos Filho and Oliveira1999: 62; Absalão and Pimenta, Reference Absalão and Pimenta2005: 17, fig. 20.

Tricolia affinis affinis: Robertson, Reference Robertson1958: 262, pl. 138, fig. 5, pl. 139, figs. 6–8, pl. 143 figs. 1, 2, pl. 145, fig. 1; Abbott, Reference Abbott1974: 62, fig. 506.

Tricolia affinis cruenta: Rios, Reference Rios1970: 29, pl. 6; Jong and Coomans, Reference Jong and Coomans1988: 17.

Tricolia (Tricolia) affinis: Rios, Reference Rios1975: 30, pl. 8, fig. 91; Reference Rios1985: 30, pl. 13, fig. 127; Reference Rios1994: 43, pl. 14, fig. 147; Reference Rios2009: 70, text fig.

Eulithidium affine: Lyons, Reference Lyons, Camp, Lyons and Perkins1998: 16; Rosenberg et al. Reference Rosenberg, Moretzsohn, García, Felder and Camp2009: 625; Miloslavich et al., Reference Miloslavich, Díaz, Klein, Alvarado, Díaz, Gobin, Escobar-briones, Cruz-motta, Weil, Cortés, Bastidas, Robertson, Zapata, Martín, Castillo, Kazandjian and Ortiz2010: table S6; Tunnell et al., Reference Tunnell, Andrews, Barrera and Moretzsohn2010: 123, text fig.; Welch, Reference Welch2010: table S1; Gondim et al., Reference Gondim, Dias, Campos, Alonso and Christoffersen2011: 78, tab. 1; Zhang, Reference Zhang2011: 53, figs. 38(1)–38(5); Espinosa et al., Reference Espinosa, Ortea, Sanchez and Gutiérrez2012: 60; Redfern, Reference Redfern2013: 27, fig. 73A–C; Longo et al., Reference Longo, Fernandes, Leite and Passos2014: 3, tab. 1, fig. 2C; Tunnell et al., Reference Tunnell, Barrera and Moretszsohn2014: 34, text fig.; Pádua et al., Reference Pádua, Silva and Duarte2019: 112; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021: 90, figs. A, B.

Eulithidium affine cruentum: Sevilla et al., Reference Sevilla, Vargas and Cortés2003: 311.

Tricolia ‘aff.’ [sic]: Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009: 147.

Tricolia aff.inis [sic]: Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009: 151.

Tricolia affine: Daccarett and Bossio, Reference Daccarett and Bossio2011: 57, fig. 117 (incorrect termination).

Distribution: Florida, USA, to southern Brazil (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009); in Brazil, from the states of Ceará to Santa Catarina (Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021).

Habitat: Seagrass beds or coral reefs in shallow waters, 0–60 m (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009; Tunnell et al., Reference Tunnell, Barrera and Moretszsohn2014).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 170756, 1 sh; 260 m, MZSP 132136, 2 sh (viii/2005). Additional material: Lectotype MCZ 186020, Jamaica (Adams col.). Paralectotypes: NMNH 61764, Jamaica, 4 sh; ANSP 199422, Jamaica, 13 sh (Adams col.).

Measurements (in mm): Largest specimen, 4½ whorls, H = 2.4, D = 1.7.

Remarks: This common and widespread species lives in shallow waters among seagrass beds or coral reefs (Robertson, Reference Robertson1958; Tunnell et al., Reference Tunnell, Barrera and Moretszsohn2014). Since no live individuals were found in the Canopus material, the specimens examined herein were probably either carried to the sampling site by currents or attached to floating algae. A colour variation from reddish to yellowish is present in the current specimens (Figure 24A–E), but this has already been reported by Robertson (Reference Robertson1958). Nonetheless, this species is known to be widespread in the Southwestern Atlantic (Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021).

Family Skeneidae Clark, 1851

General remarks: The family Skeneidae includes minute vetigastropods historically known for their small, non-nacreous shells and a rhipidoglossate radula (Keen and McLean, Reference Keen and McLean1971). It is distributed worldwide, including deep-water and chemosynthetic environments (Marshall, Reference Marshall1988; Bouchet and Warén, Reference Bouchet and Warén1993). Considered a polyphyletic assemblage of ‘skeneimorph’ species by several authors, molecular analyses and morphological data have restricted the family to a well-supported clade within Trochoidea, closely related to Turbinidae (Williams, Reference Williams2012; Haszprunar et al., Reference Haszprunar, Kunze, Brückner and Heß2016). Over one hundred genera have been historically assigned to Skeneidae (Hickman, Reference Hickman2013). Still, only a small subset represents true skeneids as currently defined, and the familial boundaries continue to be refined through integrative anatomical and molecular research (Haszprunar et al., Reference Haszprunar, Kunze, Brückner and Heß2016). In Brazil, Skeneidae is currently represented by four genera: Haplocochlias, Lissospira, Parviturbo, and Skenea, and eight species (Pimenta, Reference Pimenta2025b).

Genus Haplocochlias Carpenter, 1864

Type species: Haplocochlias cyclophoreus Carpenter, 1864, by monotypy; Recent, Pacific.

Haplocochlias risoneideneryae Barros, Santos, Santos, Cabral & Acioli, 2002

(Figure 25A–H)

Figure 25.

Haplocochlias: (A–H) Haplocochlias risoneideneryae MZSP 93497 from Canopus Bank; (A) apertural view (H = 3.8 mm, D = 3.7 mm); (B) lateral view; (C-H) MZSP 170760 from Canopus, 3D reconstruction of shell through CT (voxel size = 5.2 μm); (C) abapertural view (H = 4.0 mm, D = 3.9 mm); (D) detail of apex showing protoconch (arrow indicates the transition); (E) detail of spire, lateral view; (F) apical view; (G) umbilical view; (H) apertural view, cross-section showing extent of umbilicus. (I–K) Haplocochlias swifti syntype ANSP 10292: (I) apertural view (D = 4 mm); (J) lateral view; (K) abapertural view; photos are e courtesy of the ANSP.

Haplocochlias risoneideneryae Barros, Santos, Santos, Cabral, and Acioli, 2002: 44, fig. 4A–D; Rubio et al., Reference Rubio, Fernández-Garcés and Rolán2013: 54, fig. 7A–F.

Haplocochlias sp. 1: Leal, Reference Leal1991: 51, pl. 4, figs. C–D.

Haplocochlias aff. swifti: Rios, Reference Rios2009: 61, text fig.

Distribution: Previously known from off northeastern Brazil, from the state of Rio Grande do Norte to Pernambuco, including the Fernando Noronha Archipelago (Rubio et al., Reference Rubio, Fernández-Garcés and Rolán2013); expanded herein north-westward to Canopus, off the state of Ceará.

Habitat: Intertidal sediments, 10–25 m (Leal, Reference Leal1991; Rubio et al., Reference Rubio, Fernández-Garcés and Rolán2013), biogenic sediment bottoms up to 240–260 m (empty shells).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 200 m, MZSP 93497, 5 sh (viii/2005); 240–260 m, MZSP 170760, 23 sh (viii/2005). Additional material: Syntype, Museu de Malacologia da UFRPE 7601, 11 sh. BRAZIL; Maranhão: R/V Amorim do Valle sta. 107, 01°15.866′S, 43°39.509′W, 46–48 m, MZSP 96109, 3 sh (PIATAM, 21/xi/2008); R/V Amorim do Valle sta. 108, 01°30.554′S, 43°20.466′W, 59 m, MZSP 94457, 1 sh (PIATAM, 21/xi/2008); Haplocochlias swifti: Syntype ANSP 10292, US Vigin Islands, St. Thomas, 18°22′N, 65°57′W (04/ii/1913).

Measurements (in mm; n = 15): 5½ whorls, H = 3.6 ± 0.2, D = 3.7 ± 0.2.

Remarks: This species is readily identified by its ivory-coloured, small (3.5–4 mm), compact, turbiniform shell (Figure 25A, B), with a predominantly globose outline accentuated by a distinct keel formed by a single, stronger spiral cord (Figure 25B, C). The protoconch is small, protruding, and glossy, consisting of ∼1 whorl; its transition to the teleoconch is marked by a slight thickening of the outer lip and the abrupt onset of sculpture (Figure 25D). The teleoconch bears numerous, evenly spaced cordlets of similar width, except for the stronger keel-forming cordlet (Figure 25F, G). The interspaces between the cordlets are sculptured with closely packed, prosocline axial striae, which are more widely spaced on the initial whorls and become denser on the body whorl (Figure 25E). The aperture is drop-shaped and strongly prosocline (Figure 25A, B), with a slightly flared inner lip forming a narrow but thick callus (Figure 25B, G), and a distinctly thickened outer lip. The umbilicus is very narrow, though not fully imperforate (Figure 25H).

Haplocochlias risoneideneryae has often been misidentified as H. swifti Vanatta, Reference Vanatta1913, in catalogues and collections (Rubio et al., Reference Rubio, Fernández-Garcés and Rolán2013). Barros et al. (Reference Barros, Santos, Santos, Cabral and Acioli2002: fig. 3) illustrated a specimen they regarded as the holotype of H. swifti, but as pointed out by Rubio et al. (Reference Rubio, Fernández-Garcés and Rolán2013), that specimen is not part of the type series. A true syntype of H. swifti, originally designated by Vanatta (Reference Vanatta1913), is illustrated herein (ANSP 10292, Figure 25I–K). Haplocochlias risoneideneryae differs from H. swifti in its more compact and narrower shell, shallower suture, lower spire, less convex whorls, finer spiral sculpture, smaller protoconch, and distinctly drop-shaped aperture. A detailed comparison between H. risoneideneryae and its only co-occurring congener, H. willami Barros, Santos, Santos, Cabral, and Acioli, 2002, was provided by Barros et al. (Reference Barros, Santos, Santos, Cabral and Acioli2002).

Although apparently uncommon, as suggested by the previously limited number of known specimens, H. risoneideneryae has been recorded from several localities along the northeastern coast of Brazil. It is now known from the states of Maranhão, Ceará, Rio Grande do Norte, and Pernambuco, representing an ∼800 km north-westward expansion of its previously known range (from ca. 4–5°S to 1°S), as well as off Espírito Santo in the southeast (Leal, Reference Leal1991), representing an over 1,400 km southward expansion (from ca. 8–9°S to 21°S). This seemingly disjunct distribution is likely the result of insufficient sampling, a pattern also observed in other species treated herein. In the Canopus assemblage, however, H. risoneideneryae is relatively abundant compared to the other skeneids.

Genus Parviturbo Pilsbry & McGinty, 1945

Type species: Parviturbo rehderi Pilsbry and McGinty, Reference Pilsbry and McGinty1945, by original designation; Recent, Atlantic.

Parviturbo brasiliensis Rubio, Rolán & Lee, 2015

Parviturbo brasiliensis Rubio, Rolán, and Lee in Rubio, Rolán, and Fernández-Garcés, Reference Rubio, Rolán and Fernández-Garcés2015: 220, fig. 30A–F.

Distribution: Only known from the type locality in Southeastern Brazil, state of São Paulo, São Vicente, Itararé Beach (centre coordinates 23°59′00″S, 46°22′00″W; Rubio et al., Reference Rubio, Rolán and Fernández-Garcés2015); expanded herein to northeastern Brazil, off the state of Ceará.

Habitat: Benthos, sublittoral, presumably shallow waters (Rubio et al., Reference Rubio, Rolán and Fernández-Garcés2015); biogenic sediment, 240–260 m (empty shells only).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240–260 m, MZSP 131283, 10 sh (viii/2005), MZSP 170761, 4 sh (viii/2005).

Measurements (in mm; n = 10): 4½ whorls, H = 1.9 ± 0.04, D = 1.9 ± 0.1.

Remarks: Parviturbo brasiliensis was originally described from two empty shells collected at the type locality in southeastern Brazil. The Canopus specimens closely match the original description, exhibiting a small (under 2 mm), ivory-white, wider-than-high globose shell (Figure 26A) with a smooth protoconch (Figure 26G). The sculpture consists of thick spiral cords (Figure 26B–F) that are triangular in section (Figure 26H), nodulous periumbilical cords with undulating axial threads forming curved lamellae in the peripheral and basal interspaces between them (Figure 26F), and equidistant axial threads on all whorls in apical view (Figure 26E). The aperture is ovate and prosocline, bearing denticles (Figure 26B, D), and the umbilicus is broad. Most notably, the columella shows a widened base forming a triangular area at its junction with the periumbilical cord (Figure 26D). The holotype illustrated by Rubio et al. (Reference Rubio, Rolán and Fernández-Garcés2015: fig. 30A, B) is remarkably similar to the Canopus specimens in outline and most other features.

Figure 26.

Parviturbo brasiliensis from Canopus Bank, MZSP 131283: (A) apertural view (H = 1.9 mm, D = 1.97 mm); (B) same, spm #2, 3D reconstruction of shell through CT (voxel size = 1.8 μm), lateral view; (C) abapertural view; (D) apertural view; (E) apical view; (F) umbilical view; (G) protoconch under SEM; (H) apertural view, cross-section showing extent of umbilicus (arrow indicates internal axial sculpture).

CT-scan analysis revealed a previously undocumented shell character (which holds true for other species studied herein, see below): a faintly marked internal sculpture within the umbilicus, situated in the well-marked interspace between the two innermost basal cords (Figure 26H). This consists of a series of axial threads delimiting rectangular pits. The onset of this pattern is externally perceptible in umbilical view (Figure 26F), but the scan demonstrates that it extends internally as far back as the earliest whorls.

The new record extends the known range of P. brasiliensis by over 2,500 km northward in Brazilian waters, from 24°S to 2°S. Such a distributional expansion from southeastern to northeastern Brazil is not entirely unexpected, as several species inhabiting similar environments studied herein display comparable ranges; for instance, D. mirifica, P. volcano, H. boffii, and H. linnei. It is therefore plausible that P. brasiliensis occurs throughout much of the Brazilian coastline at varied depths, though extensive sampling would be required to confirm this. Additionally, its bathymetric range is here expanded from the previously reported shallow waters to the 240–260 m range, based on the present material, which consists solely of empty shells.

Parviturbo cancellifer Cavallari, Pedro & Simone, new species

(Figures 27, 29F–H)

Figure 27.

Parviturbo cancellifer new species: (A–G) 3D reconstruction of Holotype MZSP 170628 shell through CT (voxel size = 2.9 μm): (A) apertural view (H = 2.3 mm, D = 2.54 mm); (B) abapertural view; (C) left lateral view; (D) apical view; (E) umbilical view; (F) detail of apex, showing protoconch; (G) apertural view, cross-section showing extent of umbilicus (arrow indicates internal axial sculpture).

ZooBank: TBD.

Type material: Holotype MZSP 170628. Paratypes: MZSP 131282, 8 sh (viii/2005); MZSP 170627, 5 sh (viii/2005), all from the type locality.

Type locality: Brazil, Ceará state, 190 km off Fortaleza, Canopus Bank, 02°14′25″S, 38°22′50″W, 240–260 m.

Diagnosis: Shell (max. width 2.6 mm) turbiniform, ivory white, distinctly wider than high, tricarinate. Teleoconch sculptured by strong, projected spiral cords with closely spaced axial riblets in interspaces, on body whorl, also intersected by strong axial ribs producing a lattice-like aspect. Peristome elliptical, prosocline (∼30°), inner surface smooth. Base sculptured by large rectangular pits between periumbilical and second innermost spiral cord. Umbilicus narrow and deep, internally sculptured by series of faint, closely packed axial threads, reaching up to third whorl.

Description: Shell (Figures 27, 29F–H) (max. width 2.6 mm) distinctly wider than high, tricarinate, with up to 4¼ convex whorls; suture channelled, well-marked; colour uniformly ivory-white (Figure 29F–H). Spire weakly elevated, with a conoid outline (∼1/6 of shell height; Figure 27A–C), prominent, broad; spire angle ∼110°. Protoconch (Figure 27F) (diameter = ∼200 μm), smooth, glossy, 1 whorl with weakly protruding nucleus; transition marked by onset of teleoconch sculpture.

Teleoconch (Figure 27A–E) with 3¼ whorls, profusely sculptured. First whorl with three prominent spiral cords intersected by weaker axial riblets, forming large squarish pits in interspaces (Figure 27F); upper spiral cord spaced from suture, forming narrow subsutural plateau (Figure 27B, D); plateau sculptured with regular sinuous axial striae (Figure 27F); middle spiral cord most prominent, forming distinct keel. Second whorl with three strong spiral cords intersected by weaker, thinner, prosocline axial ribs, producing deeper, denser, axially elongated rectangular pits (Figure 27B, D–F); cords and ribs progressively more prominent; shell becoming tricarinate. Third whorl with low angular undulations appearing on upper cord at ¼ whorl (Figure 27C, D), becoming progressively broader, sharper, and more elevated onward; wide axial ribs extending from suture to nodules and below appear at ½ whorl, becoming progressively more prominent, intercalated with numerous thinner riblets. Body whorl with seven very strong, projecting spiral cords (Figure 27G) crossed by strong prosocline axial ribs, producing nodules at intersections, more angular on upper spiral cord (Figure 27A–D); interspaces sculptured by closely spaced prosocline axial riblets, giving overall lattice-like aspect (Figure 27B).

Peristome prosocline at ∼30° (Figures 27C, 29F), elliptical, ∼1/3 shell height (Figure 27A); inner lip narrow, distinct, slightly reflected towards umbilicus (Figure 27A, E); outer lip thick (Figure 27C, E), internally smooth (Figure 27A, E). Umbilicus narrow (∼1/5 shell diameter), deep (Figures 27E, G, 29H); base with conspicuous, large rectangular pits between periumbilical and second innermost spiral cord (Figures 27E, 29H); internal umbilical sculpture of axial threads faintly delimiting shallow squarish pits, extending internally roughly up to 3rd shell whorl (Figure 27G). Operculum unknown.

Distribution: Known only from the type locality.

Habitat: Biogenic sediment bottoms, 240–260 m.

Etymology: From Latin ‘cancell-’ = lattice-like, and ‘-fer’ = bearing, carrying; used here as an adjective.

Material examined: Types. Comparative material: Parviturbo rehderi: Holotype ANSP 181312, USA, Florida, Palm Beach, North Inlet of Lake Worth, 26°46′N, 80°07′W (McGinty col., 07/vii/1945). Paratypes: LACM 2233, 1 sh; MCZ 226800, former McGinty collection, 2 sh; MCZ 207087, former McGinty collection, 2 sh; all from the type locality.

Measurements (in mm): Holotype MZSP 170628, 4¼ whorls, H = 2.3, D = 2.5; Paratypes (adult specimens, n = 6), 4¼ whorls, H = 2.1 ± 0.1, D = 2.5 ± 0.1.

Remarks: The keeled, broad shell of P. cancellifer sp. nov., with its sharp, strongly projected spiral cords and well-marked, regular axial sculpture covering all interspaces, readily distinguishes it from most Western Atlantic congeners, except those of the ‘Parviturbo rehderi group’ sensu Rubio et al. (Reference Rubio, Rolán and Fernández-Garcés2015). From the Floridian P. rehderi Pilsbry and McGinty, Reference Pilsbry and McGinty1945, the types of which we examined (Figure 29I–K, ANSP 181312 and five paratypes), as well as from P. billfranki Rubio, Rolán, and Lee, Reference Rubio, Rolán and Fernández-Garcés2015 (British Virgin Islands) and P. boucheti Rubio, Rolán, and Lee, Reference Rubio, Rolán and Fernández-Garcés2015 (Guadeloupe), it differs by its 15–20% smaller, smooth protoconch and, more importantly, by the sculpture of the body whorl, which lacks the additional row of axial riblets between the uppermost and immediately lower spiral cords. Instead, the body whorl exhibits a characteristic cancellate pattern formed by the intersection of the spiral cords with the very strong axial ribs that appear later in ontogeny. It also differs by the presence of strong peri- and intra-umbilical sculpture consisting of rectangular pits. Furthermore, unlike P. billfranki and P. boucheti, P. cancellifer sp. nov. lacks apertural denticles. From the remaining members of the group (P. dengyanzhangi, P. granulum, and P. annejoffeae), the combination of cancellate sculpture and a wide, keeled shell constitutes a clear distinction, allowing rapid separation.

Parviturbo durian Cavallari, Pedro & Simone, new species

(Figures 28, 29A–E)

Figure 28.

Parviturbo durian new species: (A–G) 3D reconstruction of Holotype MZSP 170630 shell through CT (voxel size = 3.25 μm): (A) apertural view (H = 2.36 mm, D = 2.45 mm); (B) abapertural view; (C) left lateral view; (D) apical view; (E) umbilical view; (F) detail of apex, showing protoconch; (G) left lateral view, detail of spire.

Figure 29.

Parviturbo spp.: (A–D) Parviturbo durian new species, Paratype MZSP 131281 (H = 2.5 mm, D = 2.3 mm): (A) apertural view; (B) abapertural view; (C) apical view; (D) umbilical view. (E) 3D reconstruction of Holotype MZSP 170630 shell through CT (voxel size = 3.25 μm), apertural view, cross-section showing extent of umbilicus (arrow indicates internal sculpture of rectangular pits). (F–H) Parviturbo cancellifer new species, Paratype MZSP 131282 (H = 2.2 mm, D = 2.5 mm): (F) apertural view; (G) apical view; (H) umbilical view. (I–K) Parviturbo rehderi Holotype ANSP 181312 under SEM (H = 1.6 mm, D = 1.7 mm): (I) apertural view; (J) apical view; (K) umbilical view; photos are courtesy of the ANSP.

ZooBank: TBD.

Type material: Holotype MZSP 170630. Paratypes: MZSP 131281, 1 sh (viii/2005); MZSP 170629, 1 sh (viii/2005).

Type locality: Brazil, Ceará state, 190 km off Fortaleza, Canopus Bank, 02°14′25″S, 38°22′50″W, 240–260 m.

Diagnosis: Shell medium-large (2.3–2.5 mm) for the genus, turbiniform-globose, ivory white, strongly sculptured, with a spiky aspect. Teleoconch sculptured by strong, intercrossed axial ribs and spiral cords with large, prominent, angular nodules at intersections from 1¼ whorl onward, and small, closely packed rectangular pits between spiral cords, becoming obsolete and vanishing shortly after 2⅛ whorls. Peristome bearing 9 inner denticles. Umbilicus narrow and deep, internally sculptured by a series of closely packed rectangular pits between two innermost spiral cords, reaching 2–3 earliest whorls.

Description: Shell (Figures 28, 29A–E) (max. width 2.5 mm), turbiniform-globose, compact, nodulose, roughly as wide as high, with 4½ very convex whorls; suture well-marked; colour uniformly ivory-white (Figure 29A–D). Spire short (∼1/5 of shell height; Figure 28B, G), prominent; spire angle ∼80–85°. Protoconch (Figure 28F) exposed with a large nucleus, smooth, glossy, with 1 whorl (diameter = ∼200 μm); transition marked by marginal rim, followed by onset of teleoconch sculpture.

Teleoconch (Figures 28A–E, 29A–E) with 3½ whorls, profusely sculptured. First whorl with three spiral cords intersected by sinuous axial cordlets of similar strength, forming large square to pentagonal pits in interspaces; upper spiral cord slightly more prominent, widely spaced from suture, forming a wide subsutural plateau (Figure 28G); plateau with faint, dispersed sinuous axial striae. Second whorl with three strong spiral cords intersected by numerous weaker, thinner sinuous cordlets, producing deeper, denser, more regular rectangular pits (Figure 28B, F, G); angular nodules appear on upper cord at ¼ whorl, becoming progressively larger, sharper, more elevated, delimiting keel; subsutural plateau with ∼10 strong, broad axial ribs connecting to keel nodules, interspersed with numerous wrinkle-like axial striae, some stronger near suture, most extending suture-to-keel (Figure 28F, G). Third whorl sculpture as in second whorl, but axial ribs and keel nodules more elevated and sharper; rectangular pits between upper and second cords obsolete, vanishing at ∼⅛ whorl (Figures 28B, C, G, 29B), those between lower cords disappearing shortly after; interspaces thereafter mostly smooth, except for strong, wide axial ribs; angular nodules developing also on lower cords, becoming larger and sharper onward; spiral cords totalling 8 from whorl 3½ onward, lower cords concealed in adult shell but visible in cross-section (Figure 29E). Body whorl with eight strong, sharp, projecting spiral cords crossed by strong, broad axial ribs, producing angular nodules at intersections (Figures 28A–C, 29A–C); interspaces smooth, except for sparse weak wrinkle-like axial riblets.

Peristome prosocline (∼25°; Figure 28C), circular, ∼2/5 shell height (Figures 28A, 29A); inner lip narrow, distinct, slightly reflected towards umbilicus (Figure 28A, E); outer lip very thick (Figure 28E), bearing nine denticles, with weak columellar and adapical denticles (Figure 28A, E). Umbilicus narrow (∼1/6 shell diameter), deep (Figures 28E, 29D–E); base with conspicuous, deep rectangular pits between periumbilical and second innermost spiral cord (Figure 28E); internal umbilical sculpture of closely packed axial threads, delimiting rectangular pits, extending internally roughly up to third shell whorl (Figure 29E). Operculum unknown.

Distribution: Known only from the type locality.

Habitat: Benthos, biogenic sediment bottoms, 240–260 m.

Etymology: The specific epithet durian is a noun in apposition, derived from the common name of the durian fruit (Durio zibethinus Murr.), which is widely known for its external surface covered with rigid, sharp spines. The name directly refers to the shell morphology of the new species, whose pointed spinose ornamentation gives the shell an overall appearance reminiscent of the durian fruit.

Material examined: Types.

Measurements (in mm): Holotype MZSP 170630, H = 2.4, D = 2.4; Paratype MZSP 131281, H = 2.5, D = 2.3; Paratype MZSP 170629, H = 2.3, D = 2.3.

Remarks: Parviturbo durian sp. nov. differs from most congeners by its conspicuous shell ornamentation of strong intercrossed axial and spiral elements forming angular nodules at the intersections, giving the shell a spiky appearance. Among congeners with a comparable nodulose sculpture, P. durian sp. nov. differs from the Caribbean species Parviturbo tuberculosus (d’Orbigny, 1842), the syntypes of which were examined via photographs (NHMUK 1854.10.4.270), by being lighter-coloured, proportionally taller, and bearing much wider axial ribs, which consequently produce fewer and larger nodules per spiral cord; additionally, it shows a much stronger peri- and intra-umbilical axial sculpture delimiting rectangular pits. It can be distinguished from Parviturbo fortius Rubio, Rolán, and Fernández-Garcés, Reference Rubio, Rolán and Fernández-Garcés2015, from Guadeloupe, by the 10% smaller and smoother protoconch, presence of eight spiral cords on the body whorl (vs. seven in P. fortius), nine apertural denticles (vs. eight in P. fortius), a proportionally larger and wider aperture with a thinner outer lip, stronger axial sculpture that delimits deep rectangular pits between the periumbilical cords and inside the umbilicus (vs. absence of rectangular pits and much weaker intra-umbilical sculpture in P. fortius), and the presence of three finely scalloped spiral bands on the upper whorls. It differs from Parviturbo rectangularis Rubio, Rolán, and Fernández-Garcés, Reference Rubio, Rolán and Fernández-Garcés2015, also from Guadeloupe, by its broader axial sculpture producing larger and blunter nodules on the spiral cords, the presence of apertural denticles, and stronger axial sculpture delimiting rectangular pits at the base and within the umbilicus. Based on these characters, P. durian sp. nov. is probably assignable to the P. weberi group sensu Rubio et al. (Reference Rubio, Rolán and Fernández-Garcés2015), although whether this reflects relationships beyond conchological similarity remains to be verified with further data and analyses.

Family Solariellidae Powell, 1951

General remarks: Solariellidae is a diverse, mostly deep-water group with a circumglobal distribution. The family’s fossil record possibly dates back to the Campanian (83.6 to 72.1 Ma) of Torallola, Spain (Kiel and Bandel, Reference Kiel and Bandel2001). Species in this family are usually small (5–20 mm) and live on fine sediment to unconsolidated substrates in tropical and extra-tropical seas (Hickman, Reference Hickman, Beesley, Ross and Wells1998b; Williams et al., Reference Williams, Smith, Herbert, Marshall, Warén, Kiel, Dyal, Linse, Vilvens and Kano2013). The name was initially introduced as a subfamily of Trochidae, but was subsequently raised to the family level based on molecular analyses (Bouchet et al., Reference Bouchet, Rocroi, Fryda, Hausdorf, Ponder, Valdés and Warén2005; Williams et al., Reference Williams, Karube and Ozawa2008). The evolutionary relationships among solariellids have been widely investigated based on morphological and molecular evidence, but a comprehensive taxonomic revision that reflects recent discoveries is still lacking (Williams et al., Reference Williams, Donald, Spencer and Nakano2010; Cavallari et al., Reference Cavallari, Salvador and Simone2016b). Currently, Solariellidae includes 14 genera (Gofas, Reference Gofas2009b), and at least 5 are present in Brazilian waters, pending recent new combinations and synonyms: Bathymophila Dall, Reference Dall1881; Lamellitrochus Quinn, 1991; Microgaza Dall, Reference Dall1881; Solariella Wood, 1842; and Suavotrochus Dall, 1924 (Pimenta and Cavallari, Reference Pimenta and Cavallari2025).

Genus Solariella Wood, 1842

Synonymy see Marshall (Reference Marshall1999: 6).

Type species: Solariella maculata Wood, 1842, by monotypy; Pliocene, England.

Solariella carvalhoi Lopes & Cardoso, 1958

(Figure 30A–F)

Figure 30.

Solariella spp.: (A–F) Solariella carvalhoi: (A–C) Holotype MZSP 18446: (A) umbilical view (H = 4.9 mm, D = 5.8 mm); (B) apical view; (C) apertural view; (D–F) MZSP 122247, from Canopus; (D) umbilical view; (E) apical view; (F) apertural view (H = 3.3 mm, D = 3.75 mm). (G–N) Solariella quinni: (G–J) Holotype MZSP 77083: (G) umbilical view; (H) apical view; (I) protoconch detail; (J) apertural view (H = 6.1 mm, D = 6.2 mm); (K) MZSP 70352, from Canopus Bank, apertural view (H = 3.8 mm, D = 3.9 mm); (L–M) MZSP 93523, from Canopus: (L) umbilical view; (M) apical view; (N) apertural view (H = 4.5 mm, D = 4.2 mm).

Solariella carvalhoi Lopes and Cardoso, Reference Lopes and Cardoso1958: 59, figs. 1–3; Rios, Reference Rios1970: 23; Abbott, Reference Abbott1974: 41; Rios, Reference Rios1975: 21, pl. 4, fig. 45; Reference Rios1985: 23, pl. 10, fig. 95; Calvo, Reference Calvo1987: 59, fig. 24; Rios, Reference Rios1994: 35, pl. 10, fig. 105; Miyaji, Reference Miyaji, Amaral and Rossi-Wongtschowski2004: 78; Barros, Santos, and Francisco, Reference Barros, Santos and Francisco2008: 11, figs. 8–14; Rios, Reference Rios2009: 55, text fig.; Barros, Reference Barros2010: 58, figs. 8–14; Daccarett and Bossio, Reference Daccarett and Bossio2011: 54, fig. 92; Dornellas and Simone, Reference Dornellas and Simone2011a: 10, figs. 41–43; Cavallari et al., Reference Cavallari, Salvador and Simone2016b: 96, figs. 1–23; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021: 67, figs. A–C.

Solariella sp. 2: Leal, Reference Leal1991: 47, pl. 3, figs. E–G.

Solariella quadricincta Quinn, Reference Quinn1992: 50, figs. 1–4; Barros, Santos, and Francisco, Reference Barros, Santos and Francisco2008: 9, figs. 1–7; Barros, Reference Barros2010: 56, figs. 1–7; Miloslavich et al., Reference Miloslavich, Díaz, Klein, Alvarado, Díaz, Gobin, Escobar-briones, Cruz-motta, Weil, Cortés, Bastidas, Robertson, Zapata, Martín, Castillo, Kazandjian and Ortiz2010: table S6.

Solariella staminea Quinn, Reference Quinn1992: 53, figs. 11–12; Benkendorfer and Soares-Gomes, Reference Benkendorfer and Soares-Gomes2009: 147.

Distribution: From Venezuela to Santa Catarina state in southern Brazil (Cavallari et al., Reference Cavallari, Salvador and Simone2016b; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021).

Habitat: Sandy and calcareous bottoms, biogenic sediment, from 0 to 350 m (Cavallari et al., Reference Cavallari, Salvador and Simone2016b; Dornellas et al., Reference Dornellas, Amaral, Simone, Steiner, Amaral and Borges2021).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240 m, MZSP 122247, 8 sh (viii/2005); 240–260 m, MZSP 88203, 1 sh (viii/2005), MZSP 170762, 3 sh (viii/2005). Additional material: Holotype MZSP 18446, Moreira col. (11/xi/1956).

Measurements (in mm): Largest adult specimen (MZSP 122247), 5¼ whorls, H = 4.2, D = 5.2.

Remarks: The Canopus specimens agree well with the holotype of S. carvalhoi. They generally exhibit a lighter ground colour, ranging from white to light cream (Figure 30D–F), but otherwise conform to the complementary description provided by Cavallari et al. (Reference Cavallari, Salvador and Simone2016b), who emphasised the marked conchological variation of this species. Some individuals examined herein are also strikingly similar to the holotype (Figure 30A–C), particularly in their relatively broader shell outline (Figure 30F). Moreover, S. carvalhoi can be readily distinguished from its local congener S. quinni Barros and Pereira, 2008 (Figure 30G–N) by its larger and proportionally wider shell, much broader umbilicus, which was already highlighted as diagnostic by Lopes and Cardoso (Reference Lopes and Cardoso1958), as well as by its more delicate axial and more strongly developed spiral sculpture. The other two congeners reported from the region, S. quadricincta Quinn, Reference Quinn1992, and S. staminea Quinn, Reference Quinn1992, overlap in distribution with S. carvalhoi and are currently regarded as junior synonyms of the latter (Cavallari et al., Reference Cavallari, Salvador and Simone2016b). Accordingly, the occurrence of S. carvalhoi in Canopus falls within the species’ known range. Finally, it is worth noting that the only designated paratype of S. carvalhoi, originally intended to be housed in the Paulo de Sá Cardoso Private Collection, is now considered probably lost (J. Heise, pers. comm.).

Solariella quinni Barros & Pereira, 2008

(Figure 30G–N)

Solariella quinni Barros and Pereira in Barros, Santos, and Francisco, Reference Barros, Santos and Francisco2008: 13, figs. 15–21; Barros, Reference Barros2010: 60, figs. 15–21; Cavallari et al., Reference Cavallari and Simone2016: 44.

Distribution: Known only from the type locality at Pernambuco, northeastern Brazil (Barros et al., Reference Barros, Santos and Francisco2008); expanded herein to north-westward to Canopus, off the state of Ceará.

New records: Northeastern to southeastern Brazil, off Ceará and Espírito Santo states.

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 240 m, MZSP 70352, 1 sh (xi/2005); 240–260 m, MZSP 170763, 1 sh; 260 m, MZSP 93523, 1 sh (viii/2005). Additional material: Holotype MZSP 77083, Brazil, Pernambuco, 08°09′S, 34°34′W, gravel bottom, 69–71 m (19.XII.2004). Paratypes: Brazil, Pernambuco, MZSP 77082, 08°11′S, 34°34′W, 66–71 m (18/xii/2004); MZSP 77084, 08°11′S, 34°36′W, 69–71 m (19/xii/2004); MZSP 77085, 08°11′S, 34°36′W, 69–71 m (19/xii/2004). BRAZIL; Espírito Santo: off São Mateus, Abrolhos Slope, MD55 sta. DC73, 18°59′S, 37°48′W, 607–620 m, MNHN, 17 sh (Bouchet, Leal and Métivier col., 27/v/1987); MD55, sta. CB80, 18°59′S, 37°49′W, 290–315 m, MNHN, 2 sh (Bouchet, Leal and Métivier col., 28/v/1987).

Measurements: Largest specimen (MZSP 93523), 5 whorls, H = 4.5 mm, D = 4.3 mm.

Remarks: The present specimens agree well with the type material of S. quinni (Figure 30G–I), although all individuals from Canopus are juveniles (Figure 30K–N). The species can be readily diagnosed by the characteristic sculpture of the whorl shoulder and base, and by the narrow, internally smooth umbilicus (Figure 30G, L), as stressed by Barros et al. (Reference Barros, Santos and Francisco2008). Solariella quinni was originally described by Barros et al. (Reference Barros, Santos and Francisco2008); a subsequent paper by the same senior author (Barros, Reference Barros2010) reproduces the earlier description verbatim and is considered herein a republication, despite lacking explicit reference to the original work.

This species closely resembles S. lacunella (Dall, Reference Dall1881) from the Caribbean, but may be distinguished by its smaller size (maximum H = 5 mm, compared with 8.5 mm in S. lacunella); the stronger axial sculpture with prominent ribs on the whorl shoulder (Figure 30H, M); weaker spiral cords, particularly on the base; a more convex base; and a much narrower umbilicus.

The new records provided here considerably extend the species’ distribution, ca. 670 km northward from off Pernambuco to Ceará, and nearly 1,200 km southward to Espírito Santo, in southeastern Brazil (MD55 specimens). The bathymetric range is also expanded from a previous maximum depth of 71 to 620 m, based on the MD55 material comparatively examined herein.

Family Turbinidae Rafinesque, 1815

General remarks: Turbinidae is a large family occurring in virtually all oceans, from the high intertidal zone to deep-sea habitats, predominantly in tropical and subtropical waters, and more rarely in temperate regions (Williams and Ozawa, Reference Williams and Ozawa2006; Williams, Reference Williams2007). The family has a rich fossil record extending back to the Permian (Hickman and McLean, Reference Hickman and McLean1990). Traditionally, turbinids have been defined by shell morphology and by the presence of a calcareous operculum (as in Turbinacea Rafinesque, 1815). Subsequent studies incorporated radular characters and additional morphological traits, providing a more comprehensive characterisation of the group (Hickman and McLean, Reference Hickman and McLean1990; Williams and Ozawa, Reference Williams and Ozawa2006). Nonetheless, molecular analyses demonstrated that the family is polyphyletic (Williams and Ozawa, Reference Williams and Ozawa2006). Williams et al. (Reference Williams, Karube and Ozawa2008) subsequently redefined the group, recognising five subfamilies: Margaritinae Thiele, Reference Thiele1924; Prisogasterinae Hickman and McLean, Reference Hickman and McLean1990; Skeneinae Clark, 1851; Tegulinae Kuroda, Habe, and Oyama, 1971; and Turbininae. In a subsequent classification based on further molecular data and a larger assemblage of species, Williams (Reference Williams2012) elevated some of these subfamilies to the family level, and only Prisogasterinae and Turbininae remained in Turbinidae. More recently, Dornellas et al. (Reference Dornellas, Couto and Simone2020) recovered Tegulinae (elevated to family status by Williams, Reference Williams2012) as a monophyletic subfamily within Turbinidae based on morphological characters. The genus Turbo within Turbininae is currently represented in Brazil by three species: Turbo castanea Gmelin, 1791; Turbo canaliculatus Germann, 1781; and Turbo heisei Prado, Reference Prado1999 (Dornellas APS, Reference Dornellas2025).

Genus Turbo Linnaeus, 1758

Type species: Turbo petholatus Linnaeus, 1758, by subsequent designation (Montfort, Reference Montfort1810); Recent, Indian Ocean, Red Sea.

Turbo heisei Prado, 1999

(Figure 31)

Synonymy see Cavallari and Simone (Reference Cavallari and Simone2016). Complement:

Turbo heisei: Cavallari and Simone, 2016: 10, fig. 1A–K, fig. 2A.

Distribution: Brazil, from Ceará to Espírito Santo, including regional oceanic Islands (Cavallari and Simone, Reference Cavallari and Simone2016).

Habitat: Benthos, from 0–92 m depth (live specimens); down to 620 m (empty shells only; Cavallari and Simone, Reference Cavallari and Simone2016).

Material examined: BRAZIL; Ceará: off Camocim, MZSP 85519, 5 sh (Monteiro col., 2007); 190 km off Fortaleza, Canopus Bank, 60 m, MZSP 53748, 1 sh (viii/2005), MZSP 66563, 1 sh (viii/2005), MZSP 67308, 1 sh (viii/2005), MZSP 70220, 1 sh (viii/2005); MZSP 72084, 1 sh (xi/2005); 240–260 m, MZSP 122842, 23 sh (viii/2005), MZSP 170764, 14 sh + fragments (viii/2005). Comparative material: Turbo canaliculatus: BRAZIL: Rio Grande do Norte: off Touros, 10–15 m, MZSP 70119, 1 sh (viii/2006).

Measurements (in mm): Holotype MORG 40998, 6 whorls, H = 20.2, D = 17.7; Paratype MZSP 131294, 6 whorls, H = 20.2, D = 17.2. Non-types: Largest individual (MZSP 70220), 5½ whorls, H = 16.9, D = 17.3.

Remarks: The sculpture and colouration of the examined specimens closely match both the paratype and the original description (Prado, Reference Prado1999). Ground colouration is variable, ranging from intense yellowish-orange to reddish brown, sometimes with a faint greenish hue. The lighter axial stripes described by Prado (Reference Prado1999) are present in most specimens, usually more conspicuous in apical view (Figure 31B, F, G). In addition, the basal region of the shell is often marked by a distinct lighter stripe extending from the outer lip attachment to the umbilicus, a feature not mentioned by Prado but frequently observed in the present material (Figure 31H, I). Further variation includes scattered white spots and darker, spirally elongated markings in some individuals (Figure 31H, J). Such colour variation does not appear to be geographically structured, as the full spectrum of patterns can be observed within single assemblages. A similar degree of variation applies to shell proportions: although both broader and taller forms occur, the latter are more common in the present sample (Cavallari and Simone, Reference Cavallari and Simone2016).

Figure 31.

Turbo heisei: (A–D) paratype MZSP 131294: (A) protoconch detail, apical view; (B) apical view (D = 17.2 mm); (C) umbilical view; (D) apertural view (H = 20.2 mm); (E) MZSP 85519, off Camocim, Ceará state, apertural view (H = 16.2 mm); (F) MZSP 122842, juvenile specimen, off Fortaleza, Canopus Bank, Ceará state, apertural view (H = 7.1 mm); (G–H) MZSP 70220, same locality: (G) apical view (D = 17.3 mm); (H) apertural view (H = 16.9 mm).

Turbo heisei resembles the Caribbean species Turbo cailletii Fischer and Bernardi, 1857, but differs in having a proportionally taller and smaller shell, a blunt apex, absence of a wide subsutural plateau (Tunnell et al., Reference Tunnell, Andrews, Barrera and Moretzsohn2010: 126; Redfern, Reference Redfern2013: 19, fig. 52), a more strongly impressed and channelled suture, stronger axial sculpture imparting a rougher surface, narrower and more delicate spiral cords with shallower interspaces, and an overall thinner shell. The known range of T. heisei, originally restricted to southeastern Brazil, was considerably expanded northward into northeastern Brazil by Cavallari and Simone (Reference Cavallari and Simone2016).

Superfamily Seguenzioidea Verrill, 1884

Family Seguenziidae Verrill, 1884

General remarks: Seguenziidae is a globally distributed family of deep-water snails, typically occurring between 200 and 1,000 m depth, most often on fine sedimentary substrates. The family has a comparatively rich fossil record, with the oldest known representatives dating to the Middle Palaeocene (66–56 Ma) of Greenland (Kollmann and Peel, Reference Kollmann and Peel1983). Owing to a mosaic of plesiomorphic and apomorphic traits, their phylogenetic placement, either within Vetigastropoda or in an intermediate position between Vetigastropoda and Caenogastropoda, was long debated (Haszprunar, Reference Haszprunar and Ponder1988a, Reference Haszprunar1988b; Hickman, Reference Hickman, Beesley, Ross and Wells1998a; Sasaki, Reference Sasaki1998). For decades, classification relied almost entirely on shell morphology (Quinn, Reference Quinn1983), largely because soft-part anatomy was rarely available, resulting in considerable taxonomic inconsistency. In the past decades, molecular studies have begun to clarify their phylogenetic position (Kano et al., Reference Kano, Chikyu and Warén2009; Aktipis and Giribet, Reference Aktipis and Giribet2012), though additional sampling and sequencing across taxa remain necessary to resolve relationships within the family. Currently, Seguenziidae comprises more than 20 genera (Bouchet, Reference Bouchet2010), 7 of which occur in Brazilian waters. To date, 12 seguenziid species have been recorded from Brazil (Salvador et al., Reference Salvador, Cavallari and Simone2014; Pimenta et al., Reference Pimenta, Salvador and Cavallari2025).

Genus Ancistrobasis Dall, 1889

Type species: Basilissa costulata Watson, Reference Watson1879, by subsequent designation (Dall, Reference Dall1889); Recent, Atlantic.

Ancistrobasis costulata (Watson, 1879)

(Figure 32)

Figure 32.

Ancistrobasis costulata: (A–D) MZSP 70312, from Canopus Bank: (A) apertural view (H = 3.4 mm, D = 5.0 mm); (B) apical view; (C) umbilical view; (D) protoconch detail. (E) MZSP 93485, from Canopus, apertural view (H = 3.5 mm, D = 4.8 mm). (F) MNHN, MD55 specimen from Espírito Santo, apertural view (H = 4.0 mm, D = 5.0 mm). (G) MZSP 70313, from Canopus, apertural view (H = 3.5 mm, D = 4.1 mm); (H–J) same, specimen #2: (H) apertural view (H = 3.4 mm, D = 4.2 mm); (I) apical view; (J) umbilical view; (K) same, specimen #3, apertural view (H = 3.4 mm, D = 3.7 mm); (L) same, specimen #4, protoconch detail under SEM.

Synonymy see Quinn (Reference Quinn1979), Salvador et al. (Reference Salvador, Cavallari and Simone2014). Complement:

Basilissa (Ancistrobasis) costulata var. depressa Dall, Reference Dall1889: 384, pl. 23, figs. 4, 4a. [syn. nov.]

Basilissa (Ancistrobasis) costula depressa [sic]: Boss et al., Reference Boss, Rosewater and Ruhoff1968: 103.

Basilissa (Ancistrobasis) costulata: Abbot, Reference Abbott1974: 37, fig. 241; Quinn, Reference Quinn1979: 51, figs. 85, 86.

Ancistrobasis depressa: Quinn, Reference Quinn1983: 729, fig. 39; Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009: 622.

Basilissa costulata: Absalão, Reference Absalão1989: 2.

Calliostoma frumari García, Reference García2007: 128, figs. 1–4.

Ancistrobasis costulata: Salvador et al., Reference Salvador, Cavallari and Simone2014: 537, figs. 1–3; Cavallari and Salvador, 2022: 97, figs. 1, 2.

Distribution: From Georgia, USA, to southern Brazil (Quinn, Reference Quinn1979; Rios, Reference Rios2009; Salvador et al., Reference Salvador, Cavallari and Simone2014).

Habitat: Benthos, biogenic sediment, 27–1,170 m (Quinn, Reference Quinn1979; present work).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 200 m, MZSP 93485, 2 sh (2005), MZSP 131041, 2 sh (2005); 240 m, MZSP 122375, 2 sh (2005), MZSP 122376, 1 sh (2005); 240–260 m, MZSP 88200, 1 sh (viii/2005), MZSP 88206, 1 sh (viii/2005), MZSP 88210, 3 sh (viii/2005), MZSP 170765, 6 sh; 260 m, MZSP 70312, 2 sh (viii/2005), MZSP 70313, 9 sh (viii/2005), MZSP 94233, 2 sh (xi/2005), MZSP 112575, 1 sh (2005), MZSP 121947, 2 sh (2005).

Measurements (in mm; n = 7): 6¼ whorls, H = 3.4 ± 0.3, D = 4.5 ± 0.5.

Remarks: Watson’s (Reference Watson1879) description of A. costulata was based on three empty shells, and thus, the limited material available prevented any meaningful assessment of variability in shell outline or sculpture (Cavallari and Salvador, Reference Cavallari and Salvador2022). Salvador et al. (Reference Salvador, Cavallari and Simone2014) examined a larger sample from the MD55 expedition (off southeastern Brazil). Although they provided little discussion on intraspecific variability (apart from colouration, see below), their two illustrated specimens (Salvador et al., Reference Salvador, Cavallari and Simone2014: figs. 1–3) already showed differences in rib and cord spacing, as well as in height/width ratio. The Canopus assemblage further demonstrates the conchological variation in A. costulata. Shell proportions range from distinctly broader than tall (H/D = 0.69) with more convex whorls (Figure 32A) to nearly as tall as wide (H/D = 0.86) with straighter whorl profiles (Figure 32K). Sculpture also varies: in some specimens it consists of numerous, delicate ribs with angular nodules at the intersections (Figure 32A, F), while in others it is reduced to fewer, broader ribs and cords with large, rounded nodules (Figure 32H, K). One specimen illustrated by Salvador et al. (Reference Salvador, Cavallari and Simone2014) represents an intermediate condition between these extremes (cf. Figure 32F). The protoconch morphology appears to be constant (Figure 32D, L). Still, the first teleoconch whorls may be sculptured either exclusively by axial ribs (Figure 32D) or by a combination of ribs and spiral cordlets producing a reticulate pattern (Figure 32L). Colouration also shows variability. While Watson (Reference Watson1879) described the species as pure white with a nacreous sheen (Figure 32A), cream-coloured forms are also present (Figure 32E), as already noted by Salvador et al. (Reference Salvador, Cavallari and Simone2014).

Family Chilodontidae Wenz, 1938

General remarks: Chilodontidae is a diverse family of marine snails inhabiting tropical, subtropical, and warm-temperate waters of the Atlantic and Indo-Pacific, from the intertidal zone to bathyal depths of up to 2,000 m. Based primarily on molecular evidence, the group has recently been treated as a distinct and well-supported lineage within Seguenzioidea Verrill, 1884 (Kano, Reference Kano2008; Williams et al., Reference Williams, Karube and Ozawa2008; Kano et al., Reference Kano, Chikyu and Warén2009; Aktipis and Giribet, Reference Aktipis and Giribet2012). External morphological features of chilodontids have been summarised in earlier works (Hickman and McLean, Reference Hickman and McLean1990; Hickman, Reference Hickman, Beesley, Ross and Wells1998b), but comparative morphological analyses between chilodontids and other seguenzioidean taxa remain lacking and are necessary to clarify their evolutionary affinities. The fossil record of the family extends back to the Early Mesozoic (Herbert, Reference Herbert2012). At present, Chilodontidae comprises at least 18 genera, both extant and extinct (Gofas, Reference Gofas2009a), 3 of which are known from Brazilian waters, namely Euchelus Philippi, 1847; Mirachelus Woodring, Reference Woodring1928; and Velutonia Dall, 1913 (Pimenta, Reference Pimenta2025a).

Genus Dentistyla Dall, 1889

Synonymy see Quinn (Reference Quinn1979: 34). Complement:

Antillachelus Woodring, Reference Woodring1928: 433 [fide Clench and Turner, Reference Clench and Turner1960].

Type species: Margarita asperrima Dall, Reference Dall1881, by subsequent designation (Keen, Reference Keen and Moore1960); Recent, Caribbean.

Dentistyla dentifera (Dall, 1889)

(Figures 33A–D, 35)

Figure 33.

Dentistyla types: (A–D) Dentistyla dentifera Lectotype USNM 95059: (A) apertural view (H = 6.1 mm, D = 5.6 mm); (B) umbilical view; (C) apical view; (D) protoconch. (E–H) Dentistyla sericifila Lectotype USNM 95060: (E) apertural view (H = 4.8 mm, D = 4.6 mm); (F) umbilical view; (G) apical view; (H) protoconch; photos by Barbara V. Romera. (I–L) Dentistyla asperrima paralectotype MCZ 7569: (I) apertural view (H = 4.5 mm, D = 3.9 mm); (J) lateral view; (K) apical view; (L) umbilical view; photos are a courtesy of the MCZ.

Synonymy see Quinn (Reference Quinn1979). Complement:

Dentistyla dentiferum: Quinn, Reference Quinn1979: 35, figs. 47–48 [incorrect termination].

Dentistyla dentifera: Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009: 621.

Distribution: North Carolina to Barbados (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009); expanded herein to northeastern Brazil, off the state of Ceará.

Habitat: Benthos, biogenic sediment, 70–311 m (Rosenberg et al., Reference Rosenberg, Moretzsohn, García, Felder and Camp2009; present study).

Material examined: BRAZIL; Ceará: 190 km off Fortaleza, Canopus Bank, 60 m, MZSP 53725, 1 sh (viii/2005); 240–260 m, MZSP 88201, 3 sh, MZSP 88205, 1 sh; MZSP 170766, 2 sh; 260 m, MZSP 68860, 1 sh (viii/2005), MZSP 70310, 17 sh (viii/2005; with operculae), MZSP 72004, 1 sh, MZSP 121946, 1 sh (viii/2005). Additional material: Lectotype, USNM 95059, Barbados, R/V Blake sta. 299, 13°05′N, 59°39′40″W, 256 m (10/iii/1879). Comparative material: Dentistyla asperrima: Lectotype MCZ 7568, USA, Florida, West of Dry Tortugas, R/V Blake sta. 12, 24°34′N, 83°16′W, 323 m (type locality; 1877). Paralectotypes: NMNH 95055, 1 sh, from type locality; NMNH 95096, 2 sh, MCZ 7569, 2 sh, Cuba, off Honda Bay, R/V Blake sta. 20, 23°2′30″ N, 83°11′0″W, 402 m (i/1878); NMNH 95097, 2 sh, MCZ 7570, 2 sh, Caribbean, off Barbados, 183 m (1877). Dentistyla sericifila: Lectotype USNM 95060, GRENADA, R/V Blake sta. 262, 12°01′45″ N, 61°47′25″W, 168 m (01/iii/1879).

Measurements (in mm; n = 10): 6½ whorls, H = 6.3 ± 0.5, D = 5.9 ± 0.2.

Remarks: The present specimens agree well with the original description and with the lectotype of D. dentifera (NMNH 95059; Figure 33A–D), exhibiting the characteristic conical shell (Figure 35A, D–F) with well-marked sculpture of nodulose spiral cords (Figure 35D–F, I). They also conform to Quinn’s (Reference Quinn1979) redescription, showing a spiral sculpture of two major nodulose cords (Figure 35I), the lower one forming a conspicuous keel; one to three weaker intercalary cords; a moderately large, axially striate umbilicus with one to three strong nodulose spiral cords; and an overall coarse, spiny sculpture. The Canopus specimens are also very similar to those illustrated by Quinn (Reference Quinn1979: figs. 47–48) and by Dall (Reference Dall1889).

Nearly eight years after the description of D. asperrima (Dall, Reference Dall1881; originally M. asperrima), Dall (Reference Dall1889) introduced the name dentifera as a variation, referring to it as Calliostoma (Dentistyla) asperrimum var. dentiferum. Because D. asperrima was not illustrated in the original description, comparisons were problematic, and Dall himself apparently had difficulty separating the morphotypes (Quinn, Reference Quinn1979). Woodring (Reference Woodring1928), however, understood dentifera as a distinct taxon and transferred it to his newly erected genus Antillachelus (as Antillachelus dentiferum). Clench and Turner (Reference Clench and Turner1960) likewise considered the species valid but treated Antillachelus as a synonym of Dentistyla (then ranked as a subgenus of Solariella), recombining the species as Solariella (Dentistyla) dentifera. Quinn (Reference Quinn1979) subsequently elevated Dentistyla to full generic rank and maintained D. asperrima and D. dentifera as separate species. According to him, they are very similar taxa distinguished by subtle conchological differences, such as a wider umbilicus with strong internal spiral sculpture, finer beading, more numerous basal cords, and apertural lirations in D. dentifera.

The lectotype of D. asperrima (MCZ 7568; Figure 34B–E) is considerably eroded and has a broken apex. Nevertheless, it closely matches Dall’s (Reference Dall1881) original description, particularly the ‘turreted, higher than wide’ and ‘dull white’ shell ‘with no visible nacre’; the presence of ‘four strong, simple revolving threads, not nodulated’ between the peripheral carina and the bounding rib of the umbilicus; and the ‘transverse sculpture consisting of threads following the lines of growth, rising into lamellae between the ribs, and in passing over them (except the basal ones) forming squarish projections’. Shell proportions and especially the shape of the nodules (‘projections’) emerge as some of the most distinctive differences between D. dentifera and D. asperrima: the former has a proportionally shorter and wider shell, with angular, spiky nodules, whereas in D. asperrima the nodules are squarish. Additionally, D. dentifera exhibits a coarser basal sculpture, with wider and more widely spaced axial elements, in contrast to the more delicate basal sculpture of D. asperrima, composed of very thin, closely packed threads. The examined paralectotype (MCZ 7569; Figure 33I–L) is juvenile and heavily damaged, and therefore uninformative, though it also shows the characteristic squarish nodules.

Figure 34.

Dentistyla illustrations and type: (A) Dall’s (Reference Dall1889) illustration of Calliostoma (Dentistyla) sericifilum, figs. 1 and 1a, from his plate 24. (B–E) Lectotype of Dentistyla asperrima, MCZ 7568: (B) lateral view (H = 8.2 mm, D = 7.5 mm); (C) apertural view; (D) umbilical view; (E) apical view; photos are courtesy of the MCZ.

Regarding the lectotype of D. asperrima, it is very likely the same specimen illustrated by Dall (Reference Dall1881) as D. sericifila, which he later introduced together with D. dentifera in his 1889 report on the Blake dredgings. The measurements, proportions, and overall outline of the shell correspond closely to the drawings (Figure 34A), except for the apex, which was probably damaged later. This suggests an error by Dall, since the actual holotype of D. sericifila examined herein (Figure 33E–H) agrees with the written description and measurements, but differs markedly from the published illustrations. Dentistyla dentifera can be distinguished from D. sericifila by its wider, more closely packed axial sculpture with more conspicuous nodules, and by lacking the reticulate aspect described by Dall (Reference Dall1889).

The Canopus specimens provide additional insights into intraspecific variation. In the material studied herein, the sculpture is variable: some specimens exhibit coarser ornamentation with spiky, angular nodules (Figure 35A–C), whereas others display a smoother profile with blunter nodules, resembling the lectotype of D. dentifera (Figure 33A–C). Intermediate forms are also present, with some specimens showing both conditions and even squarish nodules (Figure 35D–F), suggesting a continuum of conchological variation. In contrast to Quinn’s (Reference Quinn1979) observations, the umbilical width is highly variable, ranging from relatively wide (Figure 35C) to imperforate (Figure 35H). Based on the material examined, this variability appears to be ontogenetic, as individuals with a greater number of whorls tend to show a more obstructed or completely capped umbilical region. This suggests that the lectotypes of D. dentifera (Figure 33B) and D. sericifila (Figure 33F) may actually represent subadult individuals.

Figure 35.

Dentistyla dentifera from Canopus Bank: (A–C) MZSP 70310: (A) apertural view (H = 5.7 mm, D = 5.8 mm); (B) apical view; (C) umbilical view; (D–I) MZSP 170766, 3D reconstruction of shell through CT (voxel size = 6.7 μm): (D) apertural view (H = 6.0 mm, D = 5.2 mm); (E) abapertural view; (F) left lateral view; (G) apical view; (H) umbilical view; (I) apertural view, cross-section showing extent of umbilicus.

The basal sculpture (Figure 35C, H) is variable, both in the presence and in the strength of the spiral cords, ranging from four to five. The cords may also vary considerably: they can be smooth and lacking nodules (as noted in the original description), densely nodulose, or exhibit a combination of both conditions (Figure 35C, H). They are, however, consistently crossed by axial sculpture. The intraumbilical sculpture consists of axial lamellae. The outer lip lirations mentioned by Dall (Reference Dall1889) and Quinn (Reference Quinn1979) are indeed present in most adult specimens and appear to correspond with the external sculpture (Figure 35A, D).

Based on the number of specimens available, D. dentifera appears to be relatively abundant in Canopus. This record represents a range extension of more than 3,000 km south-eastward, from the Antillean Arc to northeastern Brazil, and marks the first occurrence of the genus in the Southwestern Atlantic.