An unusual lineage of Helotidae in mid-Cretaceous amber from northern Myanmar (Coleoptera: Nitiduloidea)

Abstract

Helotidae is a small and morphologically uniform family in Nitiduloidea. In this study, we report an unusual form of helotids, represented by Lobatihelota lescheni Li, Liu & Cai gen. nov., sp. nov. and L. iridescens Li, Liu & Cai sp. nov. from mid-Cretaceous Burmese amber. Lobatihelota is unique within the family in having a leg morphology typical of some Nitidulidae and Kateretidae (tibia widened distally, tarsomeres 1–3 bilobed, tarsomere 4 shortened). Additionally, new diagnostic characters are suggested for Trihelota from the same deposit (prosternum and mesoventrite with paired carinae, metanepisterna short, metacoxae meeting elytra laterally), and the morphological divergence of representative genera of the superfamilies Erotyloidea, Nitiduloidea and Cucujoidea is visualised using a phylomorphospace approach. ZooBank: urn:lsid:zoobank.org:pub:FE0E4D6A-8157-4E14-9240-7B87F285AEA5