The description of Prototrichalus gen. nov. and three new species from Burmese amber supports a mid-Cretaceous origin of the Metriorrhynchini (Coleoptera, Lycidae)

Abstract

Despite the many substantial advances and progress in understanding the internal evolutionary relations of several Lycidae groups, the divergence time estimation of the family within Elateroidea remains subject of debate, with estimates to as early as the mid-Jurassic. Herein we describe Prototrichalus gen. nov., and three new species: Prototrichalus sepronai sp. nov., Prototrichalus meiyingae sp. nov. and Prototrichalus milleri sp. nov., from Burmese amber of the Cenomanian Age (mid-Cretaceous), supporting an age for the tribe of at least 100 Ma. The new taxa belong to the tribe Metriorrhynchini and are the oldest recognizable beetles from this lineage, indeed, among the oldest known representatives of the Lycidae. The discovery and description of Prototrichalus and its three species provides direct evidence of the group's as a recognizable group in the mid-Cretaceous, much earlier than the recent predictions in the Late Cretaceous.