Two new species of the extinct subfamily Alitrepaninae (Coleoptera: Bostrichidae) from the Upper Cretaceous (Cenomanian) Kachin amber in northern Myanmar

Abstract

Bostrichidae is commonly referred to as auger beetles. Of them, the subfamily Alitrepaninae is the only extinct subfamily of the family Bostirichidae. Here, based on detailed characterization analysis and comparisons with other species of the Alitrepaninae subfamily, we identified two new species of the genus Poinarinius in well-preserved Upper Cretaceous (Cenomanian) amber from northern Myanmar, along with a key to Poinarinius genus. Our new species can be clearly distinguished through the feature of head visible from above, dorsal plate of the pronotum, elytra performance and length of each tarsomere. Our study deepens insight into the adaptive evolution of the subfamily Alitrepaninae regarding feeding habits and resistance, as well as discussed the ecological habits of this taxon in Cretaceous. In summary, our findings will contribute to the understanding of the diversity and evolutionary origin of Bostirichidae.