Jurassic olisthaerine rove beetles (Coleoptera: Staphylinidae): 165 million years of morphological and probably behavioral stasis

• A remarkable olisthaerine rove beetle is described from the Middle Jurassic of China.
• The discovery suggests 165 million years of morphological and probably behavioral stasis in Olisthaerinae.
• The Recent monogeneric Olisthaerinae were diverse and widespread in the Jurassic.

With only two modern species within a sole genus Olisthaerus Dejean, the extant rove beetle subfamily Olisthaerinae is one of the most poorly known groups of Staphylinidae. The only olisthaerine fossil, Anicula inferna Ryvkin, is known from the Early–Middle Jurassic of Russian Transbaikalia (Novospasskoe), but its exact systematic position needs further confirmation. The direct fossil evidence elucidating the origin and early evolution of Olisthaerinae is, not surprisingly, lacking. Here we present a new olisthaerine rove beetle, Protolisthaerus jurassicus gen. et sp. nov., from the Middle Jurassic at Daohugou in northeastern China, some 165 million years old. The exceptionally well-preserved specimen displays a remarkably similar appearance to the Recent species Olisthaerus substriatus Paykull, a modern peculiar olisthaerine beetle typically living beneath the bark of coniferous trees. With considerable resemblances to extant species in habitus, the new species possesses a few differences, including a relatively long antennomere 2, regularly striate elytra, larger size, and more importantly, a normal pronotal postcoxal process, not separated from the rest of the hypomeron by a thin suture as in modern species. The new find provides direct evidence that Olisthaerinae originated at least by the Middle Jurassic, representing one of the oldest staphylinid lineages. The remarkable morphological similarities probably suggest that P. jurassicus had the same subcortical lifestyle as its modern counterparts. The continuous presence of coniferous trees and the specific subcortical lifestyle are probably responsible for the long time morphological stasis in Olisthaerinae.

Figure optionsDownload as PowerPoint slide