New Burmese Amber Rove Beetle Fossils Assigned to the Rare Extant Subfamily Coomaniinae (Coleoptera: Staphylinidae)

SIMPLE SUMMARY: The rove beetle subfamily Coomaniinae is incredibly rare, currently comprised of one described and several undescribed species of the genus Coomania in Southeast Asia and Northern Australia. Contrary to most rove beetle groups, the subfamily is only known based on a handful of specimens. Coomaniinae is the sister group to the subfamily Staphylininae, which, in contrast, is mega-diverse and abundant in terrestrial habitats globally. In this paper we describe three new species of Coomania preserved as fossils from Upper Cretaceous Burmese amber (ca. 99 million years old). ABSTRACT: The Mesozoic, ca. 99-million-year-old Burmese amber is an incredible source of fossil beetles that have been very actively studied in recent times and have already significantly improved our knowledge about the evolution of the large family of Staphylinidae, the rove beetles. Nevertheless, new extinct taxa of high phylogenetic interest are being discovered, among which the following three rove beetle species are described here: Coomania megistos sp. nov., Coomania enkarsios sp. nov. and Coomania yini sp. nov. These fossils preserved enough morphological characters to be identified as members of the rove beetle lineage formed by Staphylininae and allied subfamilies. Based on the fragments of morphology available for observation, they are hypothesized to be the extinct members of the extant rare monobasic subfamily Coomaniinae, sister to the recently mega-diverse and abundant Staphylininae. Limitations of the available fossil material prompted us to place the new species in the extant, monobasic genus Coomania Cameron, 1939, pending a more refined generic placement when more characters become available via additional material or advanced examination techniques. The odd morphology and rarity of the extant members of Coomaniinae restricted to Southeast Asia and Northern Australia make them an enigmatic subfamily among the hyper-diverse Staphylinidae. The newly described fossils, albeit without sufficient details concealed by imperfect preservation, shed some light on the past diversity of Coomaniinae and its divergence from Staphylininae.