An Eocene fossil scarab beetle (Coleoptera: Scarabaeoidea) from Tanzania

Abstract

A fossil scarabaeoid (Coleoptera: Scarabaeoidea) Mahengea mckayi new genus, new species – the only well-preserved insect fossil and one of only a few insects found at the site – is described from an otherwise rich Eocene (~ 45.6 mya) maar Lagerstätte at Mahenge in central northern Tanzania. Numerous fossil fishes and plants have been recovered from this site and described. The dearth of insect fossils is surprising considering their richness in other deposits of similar origin and age. We suggest that the rich fish fauna present in the oxygen-rich parts of the water in the former volcanic crater lake may have scavenged most of the terrestrial insects that fell into the water. Although the fossil described here is undoubtedly that of a member of the Scarabaeoidea, the family placement remains unsure.