Contribution to the knowledge of the false click beetles from the mid-Cretaceous Kachin amber (Coleoptera, Eucnemidae), with description of a new species and a paleobiodiversity analysis

A new false click beetle species of Cenomana Otto, 2019 embedded in mid‐Cretaceous (Cenomanian, ca. 99 Ma) amber of Myanmar is described: C. annieae sp. nov.; this new species can be differentiated from its congeners based on the shape of antennal flagellomeres, antennae extending to the base of elytra at rested position, robust habitus, rugose surfaces, elytra with apical fifth narrowing posteriorly, relatively shorter elytra and flat surface of elytra, with interstices only slightly elevated. Morphological studies reveal that C. annieae possesses a primitive form of protibiae, with two apical spurs, indicating that Cenomana may represent an early stage of evolution of Eucnemidae. In addition, we performed taxonomic diversity analyses of Burmite Eucnemidae at generic level including all the documented eucnemids in Burmese amber, highlighting the first attempt to estimate the palaeobiodiversity of Eucnemidae. Despite the potential bias due to the incomplete sampling data, our results reveal that current studies have sampled 67.5% eucnemid genera in Burmese amber biota and show an increase of sample coverage after the inclusion of C. annieae. The sample coverage also suggests that our knowledge of paleobiodiversity of Mesozoic false click beetles remains insufficient and more works are needed.