Two new kateretid beetle species (Coleoptera: Kateretidae) with specialized antennal scapes in males from mid-Cretaceous Kachin amber

Kateretidae is a beetle family with 15 reported fossil species, four of them with specialized antennal scape. Specialized scape represents a rare form of sexual dimorphism in Kateretidae. Here we report two new species with a special scape in males of Protokateretes Zhao, Huang and Cai, 2023, and one female individual of an unnamed species of Protokateretes. The discovery of new species provides a supplementary diagnosis of Protokateretes, and increases the biodiversity of the fossil genus. The high diversity of species in Protokateretes provides new insights into sexual dimorphism of Kateretidae in mid-Cretaceous, enriching the knowledge of potential courtship strategy of kateretid beetles in the late Mesozoic.