Data about Mecoptera and Diptera from the Early Jurassic of Germany were published by Geinitz (Reference Geinitz1883, Reference Geinitz1884, Reference Geinitz1887), Bode (Reference Bode1905, Reference Bode1953), Handlirsch (Reference Handlirsch1906–1908, Reference Handlirsch and Schröder1920, Reference Handlirsch1939), Willmann (Reference Willmann and Westphal1978, Reference Willmann1984a, Reference Willmannb, Reference Willmann1989), Krzemiński & Kovalev (Reference Krzemiński and Kovalev1988), Krzemiński & Zessin (Reference Krzemiński and Zessin1990), Ansorge & Krzemiński (1994, Reference Ansorge and Krzemiński1995, Reference Ansorge and Krzemiński2002), Evenhuis (Reference Evenhuis1994), Krzemiński & Ansorge (Reference Krzemiński and Ansorge1995, Reference Krzemiński and Ansorge2000, Reference Krzemiński and Ansorge2005), Ansorge (Reference Ansorge1996, Reference Ansorge2007) and Lukashevich et al. (Reference Lukashevich, Krzemiński, Ansorge and Krzemińska1998). The best studied localities are Dobbertin and Grimmen (Mecklenburg–Vorpommern, Germany) (Handlirsch Reference Handlirsch1906–1908, Reference Handlirsch and Schröder1920, Reference Handlirsch1939; Ansorge Reference Ansorge1996, Reference Ansorge1999, Reference Ansorge2003). Comparably diverse and abundant specimens were found in the vicinity of Braunschweig (Bode Reference Bode1905, Reference Bode1953; Ansorge Reference Ansorge2003).
Less well known are temporary outcrops that were exposed during the 1970s and 1980s at the locality of Große Kley in Wolfsburg (Lower Saxony, Germany, Fig. 1) from which insects have only been recorded by Kierst & Wiesner (Reference Kierst and Wiesner1974). Most Early Jurassic insect localities of Germany are dated as early Toarcian and originate from the Posidonia shale or “Green series” clay. These localities are characterised by a high abundance of fossils in a varying state of preservation. More sclerotised wings with thick veins are generally much better preserved. Due to the fine-grained rock matrix of the carbonate nodules, the insects of the Grimmen site are the best preserved. Specimens are very often fragmented. Exceptionally rare are specimens with the whole body preserved. Therefore, it is extremely difficult to ascribe particular, separate parts to one species. Additionally, rudaceous sediment often deforms preserved fragments, which are thus too poorly preserved for determination.
Map of early Toarcian insect localities in Northern Germany.
The present material comprises six specimens of the order Mecoptera belonging to two families: Orthophlebiidae (five specimens) and Bittacidae (one specimen). Six other fossils represent the order Diptera, belonging to the following families: Ptychopteridae (two specimens); Limoniidae (two specimens); Anisopodidae (one specimen); and Mycetophiloidea (one specimen). The available fauna of Mecoptera and Diptera is similar to that of other early Toarcian localities of Germany. Two of the fossil dipterans are described here as new species.
1. Material and methods
The locality Große Kley is located in Mörse, an urban district of the city of Wolfsburg, Lower Saxony, Germany. During house building activities in the 1970s and 1980s, temporary outcrops revealed rich invertebrate and vertebrate faunas in the Posidonia shale, as well as in calcareous nodules in certain horizons. The known insect remains were found within the nodules, originating from the early Toarcian Harpoceras falciferum Zone, formed during the Toarcian Oceanic Anoxic Event (ca.181.5 Ma; Gradstein et al. Reference Gradstein, Ogg and Hilgen2012).
The material of fossil Mecoptera and Diptera described within the present study was collected by Ulrich Conrady between the years 1981 and 1984, and donated in October 1997 to one of the authors (AG) who, in 2015, deposited the material in the collections of the Geoscience Centre of the Georg-August University of Göttingen, Germany (GZG). From the collected material, six fossils have been identified as Mecoptera and six as Diptera. Most of them are sufficiently well preserved to be studied in detail. Additionally, three specimens from Grimmen, collected by Jörg Ansorge, are used for the description of a new species Archipleciomima germanica sp. nov. The redescriptions of some species were made based on the re-examination of the holotypes.
The fossil specimens were examined and photographed under alcohol using a Keyence VHX 5000 with camera VHX 5020 (in Göttingen) and a Nicon Coolpix 4500 mounted on a Carl Zeiss Jena Lumipan with a Mikrotar macro lens and a Leitz Periplan eyepiece (in Greifswald).
The Diptera wing venation terminology used in this paper is based on the system proposed by Krzemiński & Krzemińska (Reference Krzemiński and Krzemińska2003) and Krzemińska et al. (Reference Krzemińska, Krzemiński and Dahl2009), with four medial, one cubital and two anal veins. The terminology of the wing venation for Mecoptera follows Willmann (Reference Willmann1989) with some modifications made by Soszyńska-Maj et al. Reference Soszyńska-Maj, Krzemiński, Kopeć and Coram2017 (this volume).
2. Systematic palaeontology
Order Mecoptera Packard, Reference Packard1886 Infraorder Raptipedia Willmann, Reference Willmann1987 Family Bittacidae Handlirsch, Reference Handlirsch1906 (Fig. 2)
Bittacidae det., new specimen from Große Kley, GZG.INV.92007 (photograph by Alexander Gehler). Scale bar = 1 mm.
Material examined. GZG.INV.92007, Große Kley in Wolfsburg, Lower Saxony (Germany), housed in Göttingen.
Remarks. The single specimen is too poorly preserved for determination to the genus and species level. It belongs to the Bittacidae, according to following characters: elongated, narrow wing and four radial veins in radial sector.
Family Orthophlebiidae Handlirsch, Reference Handlirsch1906 Genus Orthophlebia Westwood in Brodie, Reference Brodie1845
Type species. Orthophlebia liassica (Mantell, Reference Mantell1844).
Orthophlebia is the most speciose and most commonly encountered genus of Jurassic Mecoptera. About 35 species were described from the Lias (Early Jurassic) of Germany (Bode Reference Bode1905, Reference Bode1953; Handlirsch Reference Handlirsch1906–1908, Reference Handlirsch1939; Willmann Reference Willmann and Westphal1978). Most specimens are poorly preserved and the reconstruction of the wing venation is sometimes difficult and not always explicit. According to Willmann (Reference Willmann1989) and Ansorge (Reference Ansorge1996), many species were described based on false interpretations of wing venation. Several of them were synonymised by those authors. However, the entire collections of Handlirsch and Bode have not been restudied and redescribed; further investigations are essential and are being carried out by the present authors. Additional difficulty is caused by species described only from hind wings, as they could well belong to species described only from forewings.
Orthophlebia elongata Handlirsch, Reference Handlirsch1939 (Fig. 3)
Orthophlebia elongata Handlirsch, Reference Handlirsch1939: (a) holotype 123/55, part; (b) holotype 123/55, counterpart. (Photographs by Jörg Ansorge); (c) drawing of new specimen from Große Kley, GZG.INV.92006. Scale bars = 2 mm.
Material examined. Holotype No 123/55 from Dobbertin (Mecklenburg, Germany), early Toarcian, housed in the Institute of Geography and Geology, Ernst-Moritz-Arndt University Greifswald, Germany; and five specimens from Große Kley in Wolfsburg, Lower Saxony (Germany), housed in Göttingen: No. GZG.INV.92006 – forewing, with veins well visible, distal part of the wing is missing; No. GZG.INV.92008 – distal part of the wing, wing venation well preserved; No. GZG.INV.92009a, GZG.INV.92009b, GZG.INV.92010 – wing venation less preserved, but visible characters indicate that it belongs to this species.
Emended Diagnosis. Wing dark, with spots; Rs forks into six longitudinal single veins, forkings of Rs2+3, Rs4+5 and Mb almost perfectly aligned.
Redescription. Holotype No 123/55 – forewing 12 mm long; Sc reaches the costa opposite fork of Rs1c; in costal area, one cross-vein c-sc lies opposite mid R1+2; R1 reaches costa almost opposite mid Rs1a; Rs almost equal in length to Rs2+3 and Rs2a and 1.3 times as long as R4+5; forks of Rs2+3, Rs4+5 and Mb lie almost on one line (Fig. 2); five medial veins present, Mb is free to the base of the wing, M1 more than twice as long as M1+2; three anal veins present.
Remarks. The specimens from Wolfsburg (wing length 10.9–11.8 mm; width 3.4–3.5 mm) are concordant with the holotype of Orthophlebia elongata described from Dobbertin by Handlirsch (Reference Handlirsch1939) and differ slightly in the ratio of some veins: R1 reaches outer margin slightly before mid Rs1a; Rs is 1.25 times as long as Rs1a; vein M1 only 1.75 times as long as M1+2. In our opinion, these differences are within the range of wing venation variability in this species.
Order Diptera Linnaeus, Reference Linnaeus1758 Family Ptychopteridae Osten Sacken, Reference Osten Sacken and Loew1862 Subfamily Eoptychopterinae Handlirsch, Reference Handlirsch1906 Genus Eoptychoptera Handlirsch, Reference Handlirsch1906
Type species. Eoptychoptera simplex (Geinitz, Reference Geinitz1887) – Dobbertin (Mecklenburg, Germany), Lower Toarcian.
Eoptychoptera simplex (Geinitz, Reference Geinitz1887) (Fig. 4)
Eoptychoptera simplex (Geinitz, Reference Geinitz1887), GZG.INV.92000, drawing of new specimen from Große Kley. Scale bar = 1 mm.
Material examined. No GZG.INV.92000 and GZG.INV.91999, Große Kley in Wolfsburg, Lower Saxony (Germany), housed in Göttingen.
Remarks. Two isolated wings (length 5.2–5.3 mm; width 1.6–1.7 mm) belong to this, the most common species of the family Ptychopteridae from the early Toarcian of Germany. The species was originally described by Geinitz (Reference Geinitz1887) as Phryganidium (Polycentropus) simplex in the order Trichoptera. Handlirsch (Reference Handlirsch1906) transferred it to Diptera: Eoptychopteridae. All species described by Handlirsch (Reference Handlirsch1906, Reference Handlirsch1939) and Bode (Reference Bode1953) were revised by Lukashevich et al. (Reference Lukashevich, Krzemiński, Ansorge and Krzemińska1998) and transferred to Eoptychoptera simplex. Specimens are well preserved, with clearly visible and preserved veins (Fig. 4); dark wing spots hardly visible.
Family Limoniidae Speiser, Reference Speiser1909 Subfamily Architipulinae Handlirsch, Reference Handlirsch1906 Genus Architipula Handlirsch, Reference Handlirsch1906
Type species. Architipula seebachi (Geinitz, Reference Geinitz1884) – Dobbertin (Mecklenburg, Germany), Early Jurassic (Toarcian).
Architipula bodei Handlirsch, Reference Handlirsch1939 (Fig. 5)
Architipula bodei Handlirsch, Reference Handlirsch1939: (a) photograph of holotype (by Jörg Ansorge); (b) drawing of holotype; (c) drawing of GZG.INV.92001. Scale bars = 1 mm.
Phryganidium arculiferum Bode, Reference Bode1905, p. 244, plate 6, fig. 21; Architipula bodei n. sp. Handlirsch, Reference Handlirsch1939, p. 112.
Material examined. Holotype Inst. Geol. S, Gr A.42 Nr 45, housed in Berlin in the collections of the Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), partially preserved, basal part is missing; No. GZG.INV.92001(+, −) from Große Kley in Wolfsburg, Lower Saxony (Germany), housed in Göttingen.
Emended diagnosis. Vein Sc reaching the outer margin opposite 2/3 length of vein R2+3+4; R3 almost half longer than R2+3+4; R4 slightly more than three times longer than R2+3+4.
Redescription. The preserved wing fragment 7.1 mm long, width at mid-length 2.7 mm; new specimen 7.3 mm length, 3.0 mm width; Sc reaching the costa at two thirds of length of vein R2+3+4; sc–r ending at twice its length before end of Sc; R1 ending opposite one third point of R3; cross-vein r–r (R2) at 1/5 R2+3 and R3 combined; Rs long, only partly preserved in holotype; d-cell strongly cut-off in lower part; cross-vein m–m oblique; upper margin of d-cell twice as long as its base; M1 almost 1.5 times as long as length of upper margin d-cell; cross-vein m–cu situated in fork of M3+4. Well-developed pterostigma.
Remarks. The specimen from the Wolfsburg locality is almost identical to the holotype of A. bodei Handlirsch, Reference Handlirsch1939 figured by Bode (Reference Bode1905). Slight differences in venation are within intraspecific variability.
Architipula clara Handlirsch, Reference Handlirsch1939 (Fig. 6)
Architipula clara Handlirsch, Reference Handlirsch1939, No 123/114: (a) photograph of holotype (by Jörg Ansorge); (b) drawing of holotype; (c) drawing of GZG.INV.91997. Scale bar = 1 mm.
Material examined. Holotype No 123/114 – Dobbertin (Mecklenburg, Germany), early Toarcian, housed in Institute of Geography and Geology, Ernst-Moritz-Arndt University Greifswald, Germany; No. GZG.INV.91997(+, −) Große Kley in Wolfsburg, Lower Saxony (Germany), housed in Göttingen.
Emended diagnosis. Vein Sc reaching outer margin opposite Rs forking; R3 almost 2.5 times longer than R2+3+4; R4 four times longer than R2+3+4.
Redescription. Wing length 7–7.1 mm, width 2.1–2.2 mm; Sc ending opposite forking of Rs; sc–r ending at twice its length before end of Sc; R1 long, reaching the outer margin almost opposite around one-seventh of length of vein R3; R2+3+4 very short; Rs 10 times as long as R2+3+4 and equal to veins R2+3 and R3 combined; base of d-cell deeply notched, upper margin of d-cell twice as long as its base; d-cell twice as long as stem; M1 1.25 times as long as d cell and almost twice as long as stem; cross-vein m–cu situated almost in fork of M3+4, in mid d-cell base.
Remarks. Specimen No. GZG.INV.91997 from Große Kley is most similar to A. clara, described by Handlirsch (Reference Handlirsch1939). Differences in proportions of veins are very small and considered to fall within intraspecific variability. Also similar to A. clara are A. intermedia and A. obliqua, described by Handlirsch (Reference Handlirsch1939). All these specimens and species may belong to one taxon, but this requires further research, which is ongoing (Kopeć et al. Reference Kopeć, Krzemiński, Skowron and Coram2017).
Family Anisopodidae Knab, Reference Knab1912 Genus Mesorhyphus Handlirsch, Reference Handlirsch and Schröder1920
Type species. Mesorhyphus nanus Handlirsch, Reference Handlirsch and Schröder1920; Dobbertin (Mecklenburg, Germany), early Toarcian.
The genus Mesorhyphus is a Jurassic representative of the family Anisopodidae and comprises seven species described from Asia and Europe (Rohdendorf Reference Rohdendorf1962; Kovalev Reference Kovalev1990; Ansorge & Krzemiński Reference Ansorge and Krzemiński1995; Ansorge Reference Ansorge1996; Lukashevich Reference Lukashevich2012).
Mesorhyphus ulrichi Kopeć & Gehler sp. nov. (Fig. 7)
Mesorhyphus ulrichi Kopeć & Gehler sp. nov., holotype GZG.INV.92002: (a) photograph (by Alexander Gehler); (b) drawing. Scale bars = 1 mm
Diagnosis. Vein Sc and R2+3 extraordinary long, distinguishing the new species from all other known recent and fossil Anisopodidae; cross-vein m–cu situated just before the half of d-cell base. This is by far the biggest Toarcian species of Mesorhyphus, twice as large than Mesorhyhus nanus Handlirsch, Reference Handlirsch and Schröder1920 and more than three times larger than M. nanus Ansorge, Reference Ansorge1996.
Etymology. Named to honour the collector Ulrich Conrady, who donated the specimen.
Material examined. Holotype No GZG.INV.92002(+, −) from Große Kley in Wolfsburg, Lower Saxony (Germany). Only one fore wing preserved with veins very well visible, basal part of wing is missing.
Description. Wing length 6.6 mm, width 3.5 mm; vein Sc very long, reaching costa opposite end of d-cell; R1 ends opposite one third of vein M1; R2+3 very long, 0.75 times length of R4+5; cell m2 long and narrow; cross-vein r–m situated at one-third of distance along upper edge of d-cell; M1 about 1.3 times as long as M1+2; d-cell about one quarter of length of wing; cross-vein m–cu just before mid d-cell base; Cu strongly wavy in distal part.
Superfamily Mycetophiloidea Stemgroup of Pleciofungivoridae and Pleciomimidae sensu Ansorge, Reference Ansorge1996.
Remarks: These have a reduced (faint and desclerotised) M stem (Mb) and a set of plesiomorphic characters of the superfamily. In contrast to their closest relatives Pleciofungivoridae and Pleciomimidae, they retain from a protopleciid-like ancestor with well-developed Mb, a rather long Rs and a long sigmoidally waved R2+3+4. A considerably short Sc is an apomorphic character in comparison with Protopleciidae.
Genus Archipleciomima Rohdendorf, Reference Rohdendorf1962
Type species. Archipleciomima obtusipennis, Rohdendorf, Reference Rohdendorf1962, pp 321, 1017, erroneously labeled in captions fig. 1019 – Issyk-kul (Kyrgizstan), Early Jurassic (Sinemurian).
The genus contains to date six species described from Jurassic localities of Asia (Kalugina & Kovalev Reference Kalugina and Kovalev1985; Blagoderov Reference Blagoderov1996). Ansorge (Reference Ansorge1996) reported one new representative of the genus Archipleciomima from the early Toarcian locality of Grimmen, Germany.
Archipleciomima germanica Krzemiński & Ansorge, sp. nov. (Figs 8, 9)
Archipleciomima germanica Krzemiński & Ansorge sp. nov., holotype LGA 1550: (a) drawing; (b) photograph (by Jörg Ansorge). Scale bar = 1 mm.
Archipleciomima germanica Krzemiński & Ansorge sp. nov., paratype GZG.INV.91998: (a) drawing; (b) photograph (by Alexander Gehler). Scale bar = 1 mm.
Diagnosis. New species differs from the other species in the following combination of characters: Sc short, reaching the costa beyond the half of Rs; Rs only slightly shorter than R2+3+4+5; R5 is almost 2.3 times longer than R2+3+4; cross-vein r–m in half of M1+2.
Etymology. The species is named after Germany, the country of its locality.
Material examined. Holotype No. LGA 1550 – Toarcian, Lower Jurassic, from J. Ansorge collection, Grimmen, Germany, housed in the Museum für Naturkunde, Berlin. Paratypes: LGA 1803, LGA 2282 from J. Ansorge collection, Grimmen, housed in the Museum für Naturkunde, Berlin; and GZG.INV.91998(+, −) from Große Kley in Wolfsburg, Lower Saxony (Germany); wing well preserved, with veins clearly visible.
Description. Wing length 3.4–3.5 mm, width 1.2–1.3 mm, with well-preserved veins; only anal part of wing is obscure. Vein Sc short, reaching costa beyond half of Rs; R1 almost straight on its entire length; Rs only slightly shorter than R2+3+4+5; R5 almost three times longer than Rs and 2.25 longer than R2+3+4; cross-vein r–m situated almost before mid M1+2; M1 2.75 times longer than M1+2; cross-vein m–cu situated just behind fork of Mb into M1+2 and M3+4; CuA very strongly curved in two thirds of its length. Faint pterostigma at R1 termination, bordered by the wing margin and R2+3+4.
Remarks. The new species A. germanica sp. nov. is considerably larger than a specimen of Archipleciomima sp. described by Ansorge (Reference Ansorge1996) from Grimmen, and differs from other representatives of this genus in the details of the proportions of the wing venation. The taxonomical status of the genus Archipleciomima at the family level is debatable. Kovalev (1985, in Kalugina & Kovalev Reference Kalugina and Kovalev1985) transferred this genus from the family Pleciofungivoridae into the family Protopleciidae. However, Ansorge (Reference Ansorge1996) queried whether this decision was correct. He (Ansorge Reference Ansorge1996) suggested that faint vein Mb in the genus Archipleciomima excluded this genus from the family Protopleciidae.
3. Summary
The fauna of the locality of Große Kley is generally quite similar to the fauna of the early Toarcian known from other localities in Germany, especially from the vicinity of Braunschweig, Dobbertin and Grimmen. The description of two new species, Mesorhyphus ulrichi sp. nov. (Anisopodidae) and Archipleciomima germanica sp. nov. (Mycetophiloidea), enriches our knowledge of this fauna.
4. Acknowledgements
We would like to thank Lena Lukashevich for her thorough revision and Rob Coram for his valuable comments on the first version of the manuscript. The research was fully supported by the Polish National Science Center (grant no. 2013/09/B/NZ8/03270).
