Omma


Omma is a genus of beetles in the family Ommatidae. Omma is an example of a living fossil. The oldest species known, O. liassicum, lived during the final stage of the Triassic, over 200 million years ago, though the placement of this species in Omma has been questioned. Numerous other fossil species are known from the Jurassic and Cretaceous of Europe and Asia. The only living species is Omma stanleyi, which is endemic to Australia. Three other extant species endemic to Australia that were formerly part of this genus were moved to the separate genus Beutelius in 2020. ''Omma stanleyi is strongly associated with wood, being found under Eucalyptus bark and exhibiting thanatosis when disturbed. Its larval stage and many other life details are unknown due to its rarity. Males are typically 14–20 mm in length, while females are 14.4-27.5 mm. Omma stanleyi'' occurs throughout eastern Australia from Victoria to Central Queensland.

Description

According to Li, Huang & Cai, 2021, Omma is distinguished from other ommatid beetles by the following characters:

Species, temporal and spatial distribution

The following extinct and extant species have been described.
Taxa labelled are considered questionable by Kirejtshuk, 2020
Omma stanleyi, recent, Australia

Fossil species