Chelonarium Fabricius, 1801

Alekseev, Vitalii I., Mitchell, Jerit, McKellar, Ryan C., Barbi, Mauricio, Larsson, Hans C. E. & Bukejs, Andris, 2021, The first described turtle beetles from Eocene Baltic amber, with notes on fossil Chelonariidae (Coleoptera: Byrrhoidea), Fossil Record 24 (1), pp. 19-32 : 20

Genus Chelonarium Fabricius, 1801

Remarks

The studied amber specimens possess the combination of characteristics unequivocally corresponding to the family Chelonariidae : biconvex body shape (i.e. fusiform in lateral view), head declined under semicircular pronotum and not visible in dorsal view, tarsomere 3 of the pentamerous tarsi with long membranous lobe, pronotum and scutellum distinctly crenulate basally, pro- and mesosternum with deep groove-like excavation for reception of the basal antennomeres, ventral side of body with depressions for reception of legs, and anterior edge of pronotum curving downwards and posteriad.

Based on the presence of the above-mentioned characteristics and the following set of characteristics, both chelonariid specimens under consideration from Baltic amber are similar to Chelonarium representatives from the Recent fauna and can be considered as congeneric: (1) pronotum margined anteriorly and laterally with complete sharp carina (in contrast to pronotum without such completely surrounding sharp carina in Brounia Sharp or Pseudochelonarium Pic ), (2) hypomera with depressions for reception of forelegs (absent in Brounia , only weakly developed in Eochelonarium Kirejtshuk ), and (3) protibiae flattened (narrow in Eochelonarium and Brounia ) and with spinose outer margin.