? Praphennium gen. nov.: Extant mite killers meet their Cenomanian relatives (Coleoptera: Staphylinidae: Scydmaeninae: Cephenniini)

摘要

?Praphenniumgen. nov. is described to include ?Praphennium carinatumsp. nov. from the Cenomanian Myanmar amber. Two other species are placed in the same genus, but they remain unnamed. This is the first known extinct genus of the large tribe Cephenniini that includes cosmopolitan extant ant-like stone beetles with uniquely modified mouthparts adapted to feed on armored mites. ?Praphenniumshares most exoskeletal characters with its extant relatives, and the structure and position of its hypognathous head suggest that the adults were also specialized predators that fed on heavily sclerotized oribatid or uropodine mites. One of the studied specimens seems to be teratological, with a reduced number of antennomeres, representing the first such a case in the fossil record of Scydmaeninae. Together with a previously known Turonian ?Hyperstenichnusof Glandulariini, the discovery of ?Praphenniumsupports early origins of acarophagy among Scydmaeninae, the only group of beetles that have adapted to feeding on this well-protected group of soil arthropods. A preliminary phylogenetic analysis suggests a close relationship between ?Praphenniumand the extant generaCephennodesandHlavaciellus, and this clade might have likely evolved within the Eurasian part of Laurasia.