Bipogonia fortis 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 : 262-264

Bipogonia fortis Li, Kundrata & Cai sp. nov.

( Figs 5–7 )

Material. Holotype, sex unknown NIGP179431 ( NIGP).

Etymology. The specific name refers to the robust appearance of the species.

Locality and horizon. Amber mine located near Noije Bum Village, Tanai Township, Myitkyina District, Kachin State, Myanmar; unnamed horizon, mid-Cretaceous, Upper Albian to Lower Cenomanian.

Diagnosis. Body approximately 2.1 times as long as wide (versus 2.6 times as long as wide in Bipogonia trivialis sp. nov.). Prosternum moderately broad, about 1.7 times as wide as long (versus 1.2–1.3 times as wide as long in B. trivialis sp. nov.). Metaventral discrimen (almost) complete ( Fig. 6D ).

Description. As for the genus, except for the following characters: Body broad, 5.2 mm long, 2.5 mm wide. Prosternum broad. Elytral surface with puncture rows (their number cannot be counted due to visibility problems). Mesocoxal cavities separated by more than two times the shortest diameter of coxal cavity. Metaventral discrimen (almost) complete. Hind wing well-developed. Radial cell moderately elongate, about 2.3 times as long as wide; inner posterobasal angle almost right. Abdominal ventrite 5 about 1.6 times as long as ventrite 4.

Remarks. Extant Artematopodidae may display some degree of sexual dimorphism in body robustness, antennal length/serration, or pronotal shape (sinuation of lateral pronotal margin) ( Hopping 1936; Sakai 1982; Lawrence; 2005; Yoshitomi 2018). Usually, the body is slightly more thickened in females than males. However, the specimen of B. fortis here is distinctly wider than B. trivialis . Besides, no dimorphic prosternum or metaventral discrimen as seen in our fossils has been reported before. Thus, we believe that B. fortis is more likely to represent a separate species, rather than a specimen of the opposite sex of B. trivialis .

Figures

FIGURE 5. General habitus of Bipogonia fortis Li, Kundrata & Cai gen. et sp. nov., holotype, NIGP179431, under incident light. A, Dorsal view. B, Ventral view. Scale bars: 1.5 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.