The first record of mayflies (Ephemeroptera: Leptophlebiidae) from Cambay amber suggests a Gondwanan mayfly fauna in Early Eocene India

Abstract

Insect inclusions in Early Eocene Indian Cambay amber represent the fauna of the drifting Indian plate just prior to its collision with Asia, which led to the uplift of the Himalayas. Despite the fact that India represented a fragment of Gondwana, taxa with Gondwanan affinities are nearly absent in Cambay amber. This phenomenon is caused by extinctions on the drifting Indian plate triggered by extensive volcanism on the one hand, and, on the other, the subcontinent’s relative proximity to neighbouring landmasses, which facilitated faunal exchange as early as during India’s northward passage. Here, we present a description of the first mayfly fossils from Cambay amber, consisting of two male imagoes from the family Leptophlebiidae, clade Atalophleboculata. We describe one of the studied specimens as Aikahika veta gen. et sp. nov. This record represents the oldest unambiguous occurrence of Atalophleboculata, reaching its highest extant diversity in the fragments of former Gondwana, where it most likely originated. The mayfly fossils reported herein thus probably constituted one of the few Gondwanan survivors on the drifting Indian plate.