At the dawn of the great rise: †Ponomarenkia belmonthensis (Insecta: Coleoptera), a remarkable new Late Permian beetle from the Southern Hemisphere

Abstract

The first complete beetle body fossil from the Australian early Late Permian fossil site Belmont is described here, †Ponomarenkia belmonthensis sp. nov., attributed to a new extinct family †Ponomarenkiidae. Shortly before a dramatic biodiversity crisis at the end of the Palaeozoic, it documents profound transitions in the evolution of Coleoptera, today by far the most species-rich group of insects and the largest order of organisms. †Ponomarenkia displays transitional states of several important characters, excluding it from the ancestral earliest stem-group coleopterans (e.g. †Tshecardocoleidae), but also from the four ‘modern’ extant suborders. In contrast to †Tshecardocoleidae, †Permocupedidae and †Rhomboleidae, it lacks the ancestral very broad and apically truncated prosternal process and a broad prothoracic postcoxal bridge, features suggesting a position in Coleoptera sensu stricto, i.e. the crown group of beetles. However, it does not share apomorphic features with extant Archostemata (e.g. narrowed neck region), Polyphaga (e.g. internalized propleura), Adephaga (e.g. elongated metacoxae with strongly developed metacoxal plates) or Myxophaga (broadly separated mesocoxae). †Ponomarenkia likely belongs in the stem group of one of the extant suborders or in the stem group of a clade comprising more than one of them.http://zoobank.org/urn:lsid:zoobank.org:pub:BEC74A0C-C902-4326-8549-7F5D5E99E0C3