New discoveries prompt reinterpretations of one of the most enigmatic echinoderm classes, the Cyclocystoidea. Exceptionally well-preserved cyclocystoids have been discovered in the Upper Ordovician (Katian) Kirkfield and Verulam formations in the Lake Simcoe region of southern Ontario, Canada. Four different cyclocystoid taxa are present, including Cyclocystoides cf. C. scammaphoris, Nicholsodiscus cf. N. anticostiensis, Zygocycloides marstoni, and Brechincycloides stanhynei new genus new species. These specimens reveal that the central disk of cyclocystoids consists largely of perforate extraxial plates and that the ever-present sutural pores are epispires surrounded by annular plates that may or may not be in lateral contact with each other. The specimens of B. stanhynei n. gen. n. sp. are significant because they are the first cyclocystoid fossils to reveal that the hydropore/gonopore and periproct are positioned on the aboral side of the central disk. The suggestively complex marginal ring, previously of undetermined origin, represents articulated floor plates in a circular arrangement supporting a circumferential water vascular system. Furthermore, the marginal ring reveals growth zones that correspond to axes of pentaradial symmetry. In the new interpretation, cupules are tube foot basins, and channels through the marginal ossicles can be explained best in the context of the axial origin as floor plates accompanied by a cover plate system. Application of the Extraxial–Axial Theory (EAT) compels a revised understanding of key anatomies comparable with other early radial echinoderms. We document evidence for cyclocystoid orientation in life with epispires facing upward and the tube foot basins in the floor plates directed towards the substrate. The new family Brechincycloididae is proposed for all cyclocystoids whose apomorphy consists of a flat, attenuated shelf tapering away from the proximal side of each floor plate.

UUID: http://zoobank.org/605fdf27-b38b-4d41-824b-d10b139f90f5

Detailed studies of upper Cisuralian (i.e., upper lower Permian) fusulinids make it possible to decipher the paleobiogeographic relations of central Iran, as part of the Cimmerian terranes, with other Paleotethyan regions. Two sections, Bagh-e Vang and Shesh Angosht, located in east-central Iran, are revised. Four local fusulinid biozones are distinguished: upper Yakhtashian Pamirina darvasica and Sakmarella spp. Zone, lower Bolorian Misellina (Brevaxina) dyrhenfurthi Zone, mid-Bolorian Cuniculinella Zone, and upper Bolorian Misellina (Misellina) cf. M. (M.) termieri Zone (probably equivalent to the traditional Misellina (Brevaxina) parvicostata Zone). Taxonomically, the main results are as follows: (1) a clarification is provided of the fusulinid genus or subgenus “Cuniculina,” the name of which is pre-occupied, and its synonymy with Cuniculinella; and (2) a lectotype is designated for Darvasites (Alpites) sinensis (Chen, 1934). The mid-Bolorian Cuniculinella Zone is recognized for the first time in Iran. Among the Bolorian fusulinids, Cuniculinella is reported in SE Pamir, Karakoram, central Afghanistan, SW Japan, central Japan, and California, confirming the faunal affinity of the study area in east-central Iran with both Paleotethyan and Panthalassan bioprovinces. Such a distribution is considered to have resulted from combined effects of global warming during the upper Cisuralian, warm oceanic currents along the Paleotethys Ocean, and the northward drift of the Iran block toward lower paleolatitudes.

Two chondrichthyan assemblages of Late Mississippian/Early Pennsylvanian age are now recognized from the western Grand Canyon of northern Arizona. The latest Serpukhovian Surprise Canyon Formation has yielded thirty-one taxa from teeth and dermal elements, which include members of the Phoebodontiformes, Symmoriiformes, Bransonelliformes, Ctenacanthiformes, Protacrodontoidea, Hybodontiformes, Neoselachii (Anachronistidae), Paraselachii (Gregoriidae, Deeberiidae, Orodontiformes, and Eugeneodontiformes), Petalodontiformes, and Holocephali. The euselachian grade taxa are remarkably diverse with four new taxa recognized here; the Protacrodontidae: Microklomax carrieae new genus new species and Novaculodus billingsleyi new genus new species, and the Anchronistidae: Cooleyella platera new species and Amaradontus santucii new genus new species The Surprise Canyon assemblage also has the youngest occurrence of the elasmobranch Clairina, previously only known from the Upper Devonian. The Surprise Canyon Formation represents a nearshore fluvial infilling of karstic channels, followed by a shallow marine bioherm reef, and finally deeper open water deposition. The early Bashkirian Watahomigi Formation represents open marine deposition and contains only two taxa: a new xenacanthiform, Hokomata parva new genus new species, and the holocephalan Deltodus. The relationship between the Surprise Canyon and Watahomigi chondrichthyan assemblages and other significant coeval chondrichthyan assemblages suggests that there may have been eastern and western distinctions among the Euamerican assemblages during the Serpukhovian due to geographic separation by the formation of Pangea.

UUID: http://zoobank.org/54a906b6-4873-4f84-92b5-ca0752de01aa

The Early Pennsylvanian Nagaiwa Formation contains fossils such as corals, fusulinids, and ostracodes, and its age and depositional environments have been determined by fusulinids and sedimentology. In this study, I describe the ostracode assemblages from the Nagaiwa Formation. Moreover, I provide a reconstruction of the paleogeography of northeastern Japan during the Early Pennsylvanian by comparing this ostracode assemblage with assemblages from other regions during the same period. Thirty ostracode species, including 12 genera, have been identified, most of which are endemic species and 10 of which are new: Jordanites michinokuensis n. sp., Thuringobolbina ikeyai n. sp., Aechmina iwatensis n. sp., Pseudobythocypris asiatica n. sp., P. zipangu n. sp., P. siveteri n. sp., Platyrhomboides tohokuensis n. sp., P. japonica n. sp., Healdia ofunatensis n. sp., and H. rikutyuensis n. sp. Two of these species are also found in central Japan. The ostracodes from the Nagaiwa Formation are unique when compared with any other similarly aged assemblages.

UUID: http://zoobank.org/c43f0787-4bb6-45d1-9c12-54a747c0b040

Twenty-six genera and 34 species of early Miocene Indian shallow-marine ostracodes were examined for taxonomy and paleobiogeography. A new genus Paractinocythereis and new species Costa ponticulocarinata were described. Early Miocene Indian ostracode fauna shows strong affinity to Eocene–Miocene Eastern and Western Tethyan ostracode faunas and Miocene–Recent Indo-Pacific ostracode fauna, supporting the Hopping Hotspot Hypothesis that the Tethyan biodiversity hotspot has shifted eastward through Arabia to Indo-Australian Archipelago (IAA) together with concomitant biogeographic shifts of the Tethyan elements. The result also indicated an inverse westward distributional shift in a genus. It is important to note that Paleogene and Miocene shallow marine ostracodes from the IAA region remain poorly investigated, and more fossil ostracode data are needed to better test the Hopping Hotspot Hypothesis.

UUID: http://zoobank.org/d1e29249-8c5b-49bf-a47a-5f18e1fc4426

Biostratigraphic characterization of the Upper Ordovician in the Cincinnati region is complicated by several issues including provincialism of conodonts and graptolites, their facies dependence, the lack of biostratigraphical resolution for conodonts, and the absence of graptolites from many sections. Our study of the MY-14-01 core from Maysville (Kentucky, USA), type area for the Maysvillian Regional Stage of the Cincinnatian Series, suggests that chitinozoan biostratigraphy has the potential to strengthen the existing biostratigraphic framework based on conodonts and graptolites. Our samples usually yielded abundant, well-preserved chitinozoans in diverse populations. Many of these taxa are present in biostratigraphic reference sections from other parts of the Laurentian paleocontinent (Quebec and Anticosti Island, Canada, and Nevada, USA) and Avalonia (England and Wales). Here we provide systematic descriptions of selected chitinozoan taxa, including those of 12 new species: Conochitina rudis, Tanuchitina hooksae, Belonechitina laciniata, Hercochitina andresenae, Hercochitina anningae, Hercochitina edingerae, Hercochitina krafftae, Hercochitina polygonia, Hercochitina tharpae, Clathrochitina mangle, Angochitina bascomae, and Nevadachitina soufianei. One new name combination is proposed: Belonechitina duplicitas (Martin, 1983). This study provides a robust starting point for further advancing the Katian chronostratigraphic framework of the U.S. midcontinent.

UUID: http://zoobank.org/dc3e7fb1-a9ad-4681-8fec-701857abec4e

Marine sedimentary rocks of the late Eocene Pagat Member of the Tanjung Formation in the Asem Asem Basin near Satui, Kalimantan, provide an important geological archive for understanding the paleontological evolution of southern Kalimantan (Indonesian Borneo) in the interval leading up the development of the Central Indo-Pacific marine biodiversity hotspot. In this paper, we describe a moderately diverse assemblage of marine invertebrates within a sedimentological and stratigraphical context. In the studied section, the Pagat Member of the Tanjung Formation records an interval of overall marine transgression and chronicles a transition from the marginal marine and continental siliciclastic succession in the underlying Tambak Member to the carbonate platform succession in the overlying Berai Formation.

The lower part of the Pagat Member contains heterolithic interbedded siliciclastic sandstone and glauconitic shale, with thin bioclastic floatstone and bioclastic rudstone beds. This segues into a calcareous shale succession with common foraminiferal packstone/rudstone lenses interpreted as low-relief biostromes. A diverse trace fossil assemblage occurs primarily in a muddy/glauconitic sandstone, sandy mudstone, and bioclastic packstone/rudstone succession, constraining the depositional setting to a mid-ramp/mid to distal continental shelf setting below fair-weather wave base but above storm wave base.

Each biostrome rests upon a storm-generated ravinement surface characterized by a low-diversity Glossifungites or Trypanites trace fossil assemblage. The erosional surfaces were colonized by organisms that preferred stable substrates, including larger benthic foraminifera, solitary corals, oysters, and serpulid annelid worms.

The biostromes comprised islands of high marine biodiversity on the mud-dominated Pagat coastline. Together, the biostromes analyzed in this study contained 13 genera of symbiont-bearing larger benthic foraminifera, ~40 mollusk taxa, at least 5 brachyuran decapod genera, and 6 coral genera (Anthemiphyllia, Balanophyllia, Caryophyllia, Cycloseris, Trachyphyllia, and Trochocyathus), as well as a variety of bryozoans, serpulids, echinoids, and asterozoans. High foraminiferal and molluscan diversity, coupled with modest coral diversity, supports the hypothesis that the origin of the diverse tropical invertebrate faunas that characterize the modern Indo-Australian region may have occurred in the latest Eocene/earliest Oligocene.

Lochriea commutata (Branson and Mehl, 1941), a senior subjective synonym of Lochriea montanaensis Scott, 1942, is the type species of Lochriea Scott, 1942, one of the first conodont genera named using bedding-plane assemblages. Lochriea commutata is both wide- and long-ranging, locally stratigraphically important, and a consistently recognized Carboniferous species, despite its taxonomic journey from Spathognathodus to Gnathodus to Paragnathodus to Lochriea.

Lochriea commutata was, as Lochriea montanaensis, initially reported to contain 22+ elements, the apparatus composition of the genus being subsequently amended to 17+ elements based on Lochriea wellsi Melton and Scott, 1973, which is an untenable hypothesis because the latter was a conodontophage. Restudy of original and new bedding-plane assemblages in the mid 1970s established that the first assemblages studied were fecal, the initial reconstruction incorporated elements of two individuals, and Lochriea commutata possessed a feeding apparatus of 2P1, 2P2, 2M, 2S1, 2S2, 2S3, 2S4, and 1S0 elements. A Lochriea sp. bedding-plane assemblage was subsequently found to have the same element composition, and restudy of type material, available bedding-plane assemblages, and new fused clusters confirms that Lochriea commutata had a 15-element ozarkodinid apparatus.

While species are still assigned to Lochriea using carminiscaphate P1 elements almost exclusively, those assignments must be considered tentative until their apparatuses are determined to be similar to that of L. commutata, and until characteristics of elements other than the P1 element, particularly the makellate M element and the bipennate S3/4 element, are also taken into account.

Lochriea bigsnowyensis Scott, 1942 is reassigned to Cavusgnathus Harris and Hollingsworth, 1933.

Calyptosuchus wellesi is an aetosaur known from the upper Blue Mesa Member and lowermost Sonsela Member of the Chinle Formation in Arizona, and the Tecovas Formation of the Dockum Group of Texas. The taxon is considered biostratigraphically informative and aids in correlating Upper Triassic strata across the southwestern United States. Our anatomical understanding of Calyptosuchus was primarily based on the holotype specimen from Texas and referred specimens, including several disarticulated elements from the Placerias Quarry in northern Arizona. We provide a re-interpretation of the holotype specimen and describe two new specimens referrable to Calyptosuchus from northern Arizona. Together these specimens provide new information on the cranial anatomy, including dentition, and the positional and intraspecific variation within the carapace and vertebral column of the taxon. This new evidence suggests that the skull anatomy of Calyptosuchus is more similar to that of Neoaetosauroides and Stagonolepis than to other aetosaurs. The dentition of Calyptosuchus supports recent hypotheses suggesting that aetosaurs were more omnivorous/faunivorous. The associated carapace expands our anatomical understanding of characters that vary among trunk paramedian osteoderms. We identify variation in the vertebral column within the trunk region, including the prominence of the centrodiapophyseal lamina and anatomy of the neural spine. Additionally, we report the first documentation of co-ossified sacral vertebrae within Calyptosuchus, which is also the first observation of this state within the Aetosauria outside of the Desmatosuchini. This suggests that co-ossification of the sacral vertebrae may be more prevalent within the Aetosauria than previously recognized.

http://zoobank.org/da3735b8-edf1-465d-820a-316174ed7bf9

Non-archosaur archosauromorphs are a paraphyletic group of diapsid reptiles that were important members of global Middle and Late Triassic continental ecosystems. Included in this group are the azendohsaurids, a clade of allokotosaurians (kuehneosaurids and Azendohsauridae + Trilophosauridae) that retain the plesiomorphic archosauromorph postcranial body plan but evolved disparate cranial features that converge on later dinosaurian anatomy, including sauropodomorph-like marginal dentition and ceratopsian-like postorbital horns. Here we describe a new malerisaurine azendohsaurid from two monodominant bonebeds in the Blue Mesa Member, Chinle Formation (Late Triassic, ca. 218–220 Ma); the first occurs at Petrified Forest National Park and preserves a minimum of eight individuals of varying sizes, and the second occurs near St. Johns, Arizona. Puercosuchus traverorum n. gen. n. sp. is a carnivorous malerisaurine that is closely related to Malerisaurus robinsonae from the Maleri Formation of India and to Malerisaurus langstoni from the Dockum Group of western Texas. Dentigerous elements from Puercosuchus traverorum n. gen. n. sp. confirm that some Late Triassic tooth morphotypes thought to represent early dinosaurs cannot be differentiated from, and likely pertain to, Puercosuchus-like malerisaurine taxa. These bonebeds from northern Arizona support the hypothesis that non-archosauriform archosauromorphs were locally diverse near the middle Norian and experienced an extinction event prior to the end-Triassic mass extinction coincidental with the Adamanian-Revueltian boundary recognized at Petrified Forest National Park. The relatively late age of this early-diverging taxon (Norian) suggests that the diversity of azendohsaurids is underrepresented in Middle and Late Triassic fossil records around the world.

UUID: http://zoobank.org/e6eeefd2-a0ae-47fc-8604-9f45af8c1147.

An assemblage of 50 species of small shelly fossils is described from Cambrian Series 2 (Stage 4) strata in North Greenland, the present day northernmost part of the paleocontinent of Laurentia. The fossils are derived from the basal member of the Aftenstjernesø Formation at Navarana Fjord, northern Lauge Koch Land, a condensed unit that accumulated in a sediment-starved outer ramp setting in the transarctic Franklinian Basin, on the Innuitian margin of Laurentia. Most other small shelly fossil assemblages of similar age and composition from North America are described from the Iapetan margin of Laurentia, from North-East Greenland south to Pennsylvania. Trilobites are uncommon, but include Serrodiscus. The Australian bradoriid Spinospitella is represented by a complete shield. Obolella crassa is the only common brachiopod. Hyoliths, including Cassitella, Conotheca, Neogloborilus, and Triplicatella, are abundant and diverse, but most are represented just by opercula. Sclerites interpreted as stem-group aculiferans (sachitids) are conspicuous, including Qaleruaqia, the oldest described paleoloricate, Ocruranus?, Inughuitoconus n. gen., and Hippopharangites. Helcionelloid mollusks are diverse, but not common; they are associated with numerous specimens of the bivalve Pojetaia runnegari. The fauna compares best with that of the upper Bastion Formation of North-East Greenland, the Forteau Formation of western Newfoundland, and the Browns Pond Formation of New York, but several taxa have a world-wide distribution. Many specimens are encrusted with crystals of authigenic albite. New species: Anabarella? navaranae, Stenotheca? higginsi, Figurina? polaris, Hippopharangites groenlandicus, Inughuitoconus borealis, and Ocruranus? kangerluk.

UUID: http://zoobank.org/160a17b1-3166-4fcf-9849-a3cabd1e04a3

Low-latitude, deep-sea faunas remain poorly understood and described. Here, we systematically describe Quaternary deep-sea ostracodes from the Ocean Drilling Program (ODP) Site 925 (Ceara Rise; 4°12.2'N, 43°29.3′W; 3040 m water depth) in the equatorial Atlantic Ocean. Twenty-six genera and 52 species were examined and illustrated with high-resolution scanning electron microscopy images. Six new species are described herein: Pseudocythere spinae, Hemiparacytheridea zarikiani, Pedicythere canis, Xylocythere denticulata, Paracytherois obtusa, and Poseidonamicus sculptus. The results show that deep-sea ostracodes have a tropical faunal element that is distinctive from higher latitude ostracodes, and that is globally distributed in low latitudes. This tropical faunal component is possibly a Tethyan legacy of a fauna that was widely distributed in tropical and extratropical latitudes in deep waters during greenhouse conditions in the Cretaceous and early Cenozoic. Global cooling thereafter shrank its distribution, limiting it to tropical latitudes, perhaps with the relatively warm uppermost bathyal area acting as the source or refuge of this faunal component. Because similar present-day biogeographic patterns (i.e., presence and wide distribution of tropical deep-sea fauna) are known in other deep-sea benthic groups, this scenario might be applicable to the deep-sea benthos more broadly.

UUID: http://zoobank.org/552d4cb2-c0db-463a-ae3f-b2efcc0985df.

Numerous species of “oliviform” gastropods have been recognized in the Paleogene of the U.S. Gulf Coastal Plain, many of which have previously been allied to the “Bullia group” in the family Nassariidae, and placed in a variety of poorly defined genera. We review these species, revise their generic and familial placement, and present a phylogenetic analysis. Of 19 species considered valid, all are assigned to Olivoidea, six to Olividae—one to Oliva, five to Agaronia—and the rest to Ancillariidae. The highly variable species Ancillaria altile Conrad is referred in the genus Ancillopsis and appears to have evolved anagenetically over an interval of perhaps 20 million years. Ancillaria tenera Conrad and Ancillaria scamba Conrad are placed in the new genus Palmoliva. Monoptygma Lea is demonstrated to belong to Ancillariidae, and to contain only a single species. Specimens assigned to Lisbonia expansa Palmer are split into adults assigned to Ancillopsis altilis and juveniles (together with several other species) in the long-lived species Anbullina elliptica (Whitfield). Coastal Plain ancillariids may have evolved from one or more species of the Cretaceous–Paleocene genus Eoancilla. We agree with previous authors who have suggested that the late Eocene species Oliva mississippiensis Conrad is the earliest known representative of this genus and the subfamily Oliviinae, perhaps derived from a species of Agaronia. The oldest Agaronia is lower Eocene (Ypresian).

UUID: http://zoobank.org/b7d9f79b-c68b-4385-aba3-bb07c6d6dc87

The study of Ordovician ostracods from eastern North America has been neglected for more than 40 years, prompting the need for taxonomic updates. Newly acquired silicified materials from the Late Ordovician Crown Point Formation of Valcour Island, northeastern New York State, are here systematically described. Fifty-two species of 42 genera are identified, including three new species: Vogdesella longidorsa n. sp., Eokloedenella duodepressa n. sp. and Aviacypris valcourensis n. sp. The combination of high diversity and dominance of both beyrichiocopids and podocopids indicates that the Valcour fauna existed in a stable, shallow-water carbonate environment. Biostratigraphical evidence supports an early Sandbian age designation for the Crown Point Formation. Comparison of the Valcour fauna with others in Laurentia as well as from adjacent paleocontinents shows shared composition at the genus level, especially with Baltica, but high endemicity at the species level. This suggests a history of frequent faunal exchange with a fast speciation rate during the early Late Ordovician in the southern region of Laurentia.

UUID: http://zoobank.org/e12dc8ce-0b2a-4f9d-aca2-bf3e298d9635

The ammonite Hybonoticeras authariformis new species [M] is erected from the lower Tithonian of Mexico, adding a new example of endemism for the genus Hybonoticeras in records from epicontinental areas. The newly described species is the first evidence of unequivocal lowermost Tithonian macroconchiate hybonoticeratines reported from the Mexico-Caribbean area. Precise biostratigraphic control based on bed-by-bed sampling is first reported for the combined record of macroconchiate Hybonoticeras Breistroffer, 1947 with Mazapilites Burckhardt, 1919 in Mexico, indicating an early but not earliest Tithonian age. A preliminary revision of the type material of species assigned to the genus Mazapilites points to an inconclusive understanding of both intraspecies diversity and the real meaning of the nominal species formulated by Burckhardt, thus revealing defective knowledge about precise biostratigraphy at both the genus and species levels. Published hybonoticeratines and mazapilitines from Mexico and Cuba are revisited to update precise interpretation of their systematics, biostratigraphy, and correlation potential, and to investigate their combined occurrence. Previous information about Cuban hybonoticeratines and mazapilitines is too limited to be conclusively interpreted; their combined record cannot be demonstrated in Cuba. Special relevance is given to a potential occurrence of Mazapilites in uppermost Kimmeridgian horizons in Cuba. The obtained results update the biostratigraphic meaning and systematic interpretation of the investigated ammonites, and signal topics for future research of interest in their paleobiological and palebiogeographic interpretation.

UUID: http://zoobank.org/References/78c89620-fa2e-4de5-985d-819421a858f9

The Emigrant Formation at Clayton Ridge, Nevada, consists of 420 m of variably interbedded shale, siltstone, and limestone representing an outer shelf environment. It ranges in age from the youngest portion of the Dyeran Stage (Laurentian Waucoban Series; Cambrian Stage 4, Series 2) to Skullrockian Stage (Ibexian Series; Tremadocian Stage, Lower Ordovician). Consequently, it is condensed compared to other localities. For example, the age-equivalent succession in the House Range and the Wendover Range of Utah and Nevada, respectively, is seven times thicker.

The 100 m thick lower limestone and siltstone member of the Emigrant Formation at Clayton Ridge ranges in age from the Bolbolenellus euryparia/Nephrolenellus multinodus Zone (Laurentian Dyeran Stage) to the Cedaria brevifrons Zone (Laurentian Marjuman Stage; Drumian Stage; this study). The 40 trilobites described herein from two closely spaced sections of the lower member belong to the Glossopleura walcotti/Ptychagnostus praecurrens Zone (Laurentian Delamaran Stage; Stage 5), Ehmaniella Zone (Laurentian Topazan Stage; Stage 5), and Cedaria selwyni to C. brevifrons zones (Laurentian Marjuman Stage; Drumian Stage) zones. The lower Emigrant Formation is <10% as thick as age-equivalent age strata elsewhere in Nevada, California, and Utah. This condensed nature of the lower Emigrant Formation began with the flooding event at the beginning of the Oryctocephalus indicus biochron and the subsequent build-ups of the thick carbonate platforms to the south and northeast.

New species are Pagetia aspinosa, P. claytonensis, and Syspacephalus mccollumorum.

Devonian stromatoporoid collections have been added to the Natural History Museum, London (UK) for over 100 years. The characteristics and systematic position of these specimens, however, have received little attention. In this study, 297 Devonian stromatoporoid specimens comprising material documented by H. A. Nicholson from the UK, Germany, United States, and Canada, plus specimens described by E. A. Ripper from Australia, were re-examined. Overall, 50 species belonging to 29 genera were systematically redescribed based on recent progress, mainly including Actinostroma, Petridiostroma, Stictostroma, Pseudotrupetostroma, and Parallelopora. Three-dimensional reconstructions reveal stromatoporoid architectural patterns, crucial for enhancing understanding and revision of stromatoporoid identification. This study underscores the significance of three-dimensional reconstruction in taxonomic research on stromatoporoids. The NHMUK material is combined with data from publications and the Paleobiology Database (PBDB) to perform a network analysis of the global occurrence of Devonian stromatoporoids at the generic level; this reveals a close relationship of the global stromatoporoid fauna during the Early Devonian, indicating a widespread distribution, despite this interval being regarded as a time of global stromatoporoid contraction. The Middle Devonian assemblage shows a much higher cosmopolitan occurrence in the context of the subsequent Eifelian–Givetian global stromatoporoid proliferation, consistent with the known pattern from other studies of Middle Devonian stromatoporoids. Overall, the NHMUK collections are a valuable resource to help understand the global occurrence of Devonian stromatoporoids.

Lower and middle Cambrian strata of the eastern Mackenzie Mountains, Northwest Territories, Canada, were deposited in a semi-enclosed basin along the eastern flank of the Mackenzie Arch. The Mount Clark Formation is predominantly composed of nearshore sandstone and is overlain by deeper water siltstone, mudstone, and carbonates of the Mount Cap Formation. The contact between these formations is interpreted as a flooding surface. Trilobite biostratigraphy indicates the presence of the traditional upper Olenellus through Glossopleura zones (Cambrian Series 2, Stage 4–Miaolingian, Wuliuan) and suggests the flooding surface is diachronous, spanning the Dyeran-Delamaran boundary. Above the Olenellus Zone, the Amecephalus arrojosensis-Eokochaspis nodosa Zone, the new Aitkenaspis keelensis Zone, the new Albertelloides mischi Zone, and the Glossopleura walcotti Zone are recognized. Whereas the older zones are comparable to those in other areas of Laurentia, the trilobite faunas in the Albertelloides mischi and Glossopleura walcotti zones show a greater abundance of zacanthoidids and dolichometopids. They also have a lower diversity of ptychoparioids and oryctocephalids, and lack agnostoids, eodiscoids, dorypygids, and ogygopsidids. This suggests that zacanthoidids and dolichometopids were able to tolerate conditions that were unfavorable to the other groups, probably related to semi-restricted conditions in the basin. Four endemic species exhibit characteristics that are considered paedomorphic. This developmental process took place in three separate lineages, suggesting that heterochrony was also environmentally provoked.

New taxonomic names are authored by Handkamer and Pratt. New genera are Eobathyuriscus, Sahtuia, Mexicaspidella Aitkenaspis, Dodoella, and Mackenzieaspis. New species are Bolbolenellus dodoensis, Eobathyuriscus mackenziensis, E. macqueeni, Glossopleura youngi, Sahtuia carcajouensis, Aitkenaspis keelensis, Albertelloides eliasi, Dodoella kobayashii, Mackenzieaspis parallelispinosa, and M. divergens.

UUID: http://zoobank.org/a10a2470-853c-4ce8-bf62-7de1d2c99fab.

The Lakeview Limestone is one of the westernmost Cambrian exposures in the northwestern United States and occurs on the western edge of the Montania paleotopographic high. These deposits occur between the deeper water deposits to the west and carbonate banks and intracratonic basins to the east and provide critical link between the regions. A re-investigation of the Cambrian trilobite faunas from the lower portion of the Lakeview Limestone, Pend Oreille Lake, Idaho, is undertaken due to the inadequate illustrations and descriptions provided by Resser (1938a). Resser's type specimens and additional material are figured and described. The trilobite assemblages represent the Ptychagnostus praecurrens Zone, Wuliuan Stage, Miaolingian Series and including two new taxa: Itagnostus idahoensis n. sp., and Utia debra n. sp. Because of the similarity between some species of Amecephalus from the Lakeview Limestone to specimens from the Chisholm Shale, Nevada, the type specimens of Amecephalus piochensis (Walcott, 1886) and Am. packi (Resser, 1935), Walcott's and Resser's type specimens are re-illustrate and their taxonomic problems are discussed. Utia curio Walcott, 1924 from the Spence Shale, Utah, have never been re-illustrated since Walcott (1925), these type specimens are also re-illustrated and compared to Utia debra n. sp.

UUID: http://zoobank.org/5ef6ee5e-bddc-4395-becf-9bcea54c679c

This contribution identifies biogenic structures created by modern birds foraging in marginal aquatic settings and provides descriptions to facilitate their identification in the rock record. Biogenic structures related to foraging can be separated into those created by bills, such as peck marks, probe marks, gape marks, dabble marks, sweep marks, and bill-stir marks. Biogenic structures created by feet include stir tracks and paddle pits. Peck marks are created during visual foraging and result in shallow, solitary or paired, random or clustered, circular to subcircular pits and grooves. Probe marks are created during tactile foraging but are similar to peck marks, differing solely in their greater depth of penetration. Gape marks are formed when birds open their bill in the sediment resulting in elongated grooves. Dabble marks are larger ovoid divots emplaced by broad-billed waterbirds in subaqueous settings. Bill stirring occurs when a bird swishes its bill in a narrow trend on the sediment surface. Sweep marks are arcuate grooves emplaced in the sediment when long-billed birds forage by sweeping their bill side-to-side across the sediment–water interface.

Birds shuffling their feet in soft sediment is termed ‘foot-stirring’ and results in overprinted, side-by-side trackways. Foot-paddling dewaters the sediment and produces various pit morphologies with massive fill. Trackways emplaced during foraging are commonly characterized by variable stride length, stutter steps, and sudden changes in direction. ‘Trample grounds’ are produced by gregarious foraging flocks of birds. It is anticipated that illustrating and describing the structures produced by these behaviors will facilitate recognition of these commonly overlooked traces.