Bipogonia Li, Kundrata & Cai, 2022

Li, Yan-Da, Kundrata, Robin, Huang, Di-Ying & Cai, Chen-Yang, 2022, First Artematopodidae from mid-Cretaceous amber of northern Myanmar (Coleoptera: Elateroidea), Zootaxa 5129 (2), pp. 257-271 : 259

Genus Bipogonia Li, Kundrata & Cai gen. nov.

Type species. Bipogonia trivialis sp. nov., here designated.

Etymology. The generic name combines the prefix “ bi- ” referring to its bidentate mandibles (with both apical and subapical teeth) and the name Allopogonia . The name is feminine in gender.

Diagnosis. Antennomeres 5–10 distinctly serrate, less than twice as long as wide ( Figs 3H , 7F ). Anterior edge of frontoclypeus dentate ( Figs 3G , 7G ). Mandibles with subapical tooth ( Figs 3G , 7G ). Apical maxillary palpomere not clearly expanded apically ( Figs 4C , 7A ). Prosternum in front of coxae without paired longitudinal ridges ( Figs 3B , 7B ). Elytra with 10 puncture rows ( Fig. 3I ). Inner posterobasal angle of radial cell almost right ( Fig. 6E ).

Description. Body moderately broad to broad, 2.1–2.6 times as long as wide, surface punctate.

Antennal insertions dorsally exposed. Subantennal groove absent. Frontoclypeal suture absent; anterior clypeal margin multidentate. Antennomeres 2–4 simple, moderately slender; antennomere 5 moderately serrate; antennomeres 6–10 strongly serrate, about as long as wide. Mandibles with one apical and one subapical teeth. Maxillary palps 4-segmented; apical palpomere not clearly expanded apically. Mentum subtriangular, apically broadly rounded.

Pronotal disc subtrapezoidal, widest at base; anterior margin weakly trisinuate; anterior angles somewhat produced; surface without transverse groove. Prosternum in front coxae transverse, without paired ridges or deep pits. Prosternal process with subparallel sides, apically broadly rounded, fitting into mesoventral cavity.

Scutellar shield widely pentagonal. Elytra elongate; surface with puncture rows; epipleura developed only in anterior third. Mesoventrite short, anteriorly with well-developed mesoventral cavity. Mesocoxal cavities separated by about twice or more the shortest diameter of coxal cavity. Metaventrite more than half as long as wide, with sides widest posteriorly. Metacoxae strongly transverse, almost contiguous, extending laterally to epipleura; metacoxal plate weakly developed but complete to lateral edge.

Legs slender; tibiae slightly longer than respective femora, with two tibial spurs; tarsomeres 1 and 5 elongate; tarsomeres 3 and 4 with well-developed, bilobed membranous ventral process. Pretarsal claws simple.

Abdominal ventrites with margins denticulate. Sutures between all ventrites complete and distinct; suture between ventrites 4 and 5 only weakly curved. Ventrites 1–4 subequal in length; ventrite 5 about 1.6–1.7 times as long as ventrite 4.

Remarks. Among previously reported genera of Artematopodidae , only Allopogonia is known to possess strongly serrate antennae and prosternum without paired ridges ( Lawrence 2005; Fig. 11A, B ). In other genera, the antennae are more filiform (if slightly serrate, antennomere more than twice as long as wide), and there is a pair of longitudinal ridges on the prosternum in front of coxae continuous with the lateral margins of prosternal process. Bipogonia gen. nov. is similar to Allopogonia in having strongly serrate antennae and lacking prosternal ridges. Allopogonia , however, differs from Bipogonia in mandibles without a subapical tooth ( Fig. 11L ), which is a unique character state in Artematopodidae ( Lawrence 2005) . Bipogonia has the anterior edge of frontoclypeus dentate, while in most other artematopodids the anterior clypeal margin is rounded. Extant artematopodids have 11 or 12 puncture rows on each elytron ( Lawrence 2005; fig. 3G in Wang & Liu 2021). However, there are probably only 10 elytral puncture rows in Bipogonia gen. nov. (as seen in B. trivialis ), as well as Carinibipogonia gen. nov.

Figures

FIGURE 3. Details of Bipogonia trivialis Li, Kundrata & Cai gen. et sp. nov., holotype, NIGP179428, under confocal microscopy. A, Head, ventral view. B, Prothorax, ventral view. C, Mesothorax, ventral view. D, Mid leg. E, Metathorax and abdominal base, ventral view. F, Elytral and abdominal apices, showing the interlocking tongue (arrowhead). G, Head, dorsal view. H, Pronotum and antenna, dorsal view. I, Elytron, dorsal view.Abbreviations: a1–11, antennomeres 1–11; cl, clypeus; ep, elytral epipleuron; ey, compound eye; md, mandible; mstb, mesotibia; msts, mesotarsus; msv, mesoventrite; mt, mentum; mtc, metacoxa; mttc, metatrochanter; mtv, metaventrite; pn, pronotum; ps, prosternum; ptb, protibia; pts, protarsus; v1–5, ventrites 1–5. Scale bars: 300 μm.

FIGURE 4. Bipogonia trivialis Li, Kundrata & Cai gen. et sp. nov., paratypes. A, B, NIGP179429, under incident light. A, Dorsal view. B, Ventral view. C, D, NIGP179430, under widefield fluorescence. C, Head, dorsal view. D, Elytral apices, dorsal view. Scale bars: 1 mm.

FIGURE 6. Details of Bipogonia fortis Li, Kundrata & Cai sp. nov., holotype, NIGP179431, under widefield fluorescence. A, Head and prothorax, dorsal view. B, Head and prothorax, ventral view. C, Elytron, dorsal view. D, Posterior body, ventral view. E, Elytron and hind wing, ventral view. F, Abdominal apex, dorsal view. Abbreviations: an, antenna; el, elytron; md, mandible; mtv, metaventrite; mxp, maxillary palp; pn, pronotum; ps, prosternum; R, radial cell; v1–5, ventrites 1–5. Scale bars: 500 μm.

FIGURE 7. Details of Bipogonia fortis Li, Kundrata & Cai sp. nov., holotype, NIGP179431, under confocal microscopy. A, Head, ventral view. B, Prothorax, ventral view. C, Mesothorax, ventral view. D, Meso- and metatarsi. E, Elytral apex, showing the interlocking tongue (arrowhead). F, Antenna. G, Head, dorsal view. H, Scutellar shield, dorsal view. I, Abdominal apex, dorsal view. Abbreviations: a1–11, antennomeres 1–11; cl, clypeus; el, elytron; md, mandible; msts, mesotarsus; msv, mesoventrite; mtc, metacoxa; mtts, metatarsus; mtv, metaventrite; mxp, maxillary palp; pn, pronotum; ps, prosternum; pts, protarsus; sc, scutellum; t8, tergite VIII; v5, ventrite 5. Scale bars: 300 μm.

FIGURE 11. Details of extant Allopogonia villosa (Horn), NHMUK010189601, dissection prepared by R. A. Crowson. Photo credit: ©The Trustees of the Natural History Museum, London, licensed under CC BY 4.0. A, Head. B, Prothorax. C, D, Fore legs. E, Mesothorax. F, Elytron. G, Metathorax. H, Abdomen. I, J, Hind wings. K, Hind leg. L, Mandible. M, Labium. N, Maxilla.Abbreviations: msf, mesofemur; mstb, mesotibia; mtf, metafemur; mttb, metatibia; mtv, metaventrite; pf, profemur; ps, prosternum; ptb, protibia; pts, protarsus; v2–5, ventrites 2–5. Scale bars: 500 μm.