A Cretaceous sap beetle with specialized mandibles (Coleoptera : Nitidulidae)

Sap beetles (Nitidulidae) are species-rich, highly diverse, widely distributed and exhibit varied food habits. However, studies on nitidulids in Kachin amber are scarce, particularly those involving nitidulids with specialized mandibles. Here, we report a new genus and species of Nitidulidae, Vetunitidula mandibulata gen. et sp. nov., from mid-Cretaceous Kachin amber (approx. 99 Ma). This species is characterized by distinctly enlarged mandibles and a loose three-article antennal club, suggesting it as a stem-group nitidulid. The enlarged mandibles may be a manifestation of sexual dimorphism, as in some extant species. Together with previous studies of fossil nitidulids, our discovery highlights the remarkable diversity and morphological disparity of sap beetles during the late Mesozoic.