Cretoleptochromus archaicus gen. et sp. nov., a new genus of ant-like stone beetles in Upper Cretaceous Burmese amber (Coleoptera, Staphylinidae, Scydmaeninae)

A new genus and species of the ant-like stone beetle supertribe Mastigitae, Cretoleptochromus archaicus gen. et sp. nov., is described and figured based on an exceptionally well-preserved individual in the Upper Cretaceous (lowermost Cenomanian, ca. 99 Ma) amber from Myanmar. Cretoleptochromus is undoubtedly placed in Mastigitae based on its distinctly geniculate antennae with strongly elongate antennal scape, and pointed labial palpomere III. Cretoleptochromus is most likely the sister taxon to the extinct Palaeoleptochromus O'Keefe from the Late Cretaceous Canadian amber. Cretoleptochromus shares with Clidicini the distinct posterior collar of pronotum; with Leptomastacini the presence of mesocoxal lateroventral bristles. The new discovery may help to elucidate the relationships among the Recent three tribes, particularly for Leptomastacini and Clidicini.