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 (Rhaetian), over 200 million years ago, followed by several other species from Europe and Asia until after O. attenuatum from the Lower Cretaceous (lower Aptian), the genus then reappears in the Burmese amber during the Cenomanian, then disappears from the fossil record for the remaining 100 million years until today, with one species endemic to Australia, three other extant species that were formerly part of this genus were moved to the separate genus Beutelius in 2020. The extant Omma stanleyi is strongly associated with wood, being found under Eucalyptus bark and exhibiting thanatosis when disturbed. Its larval