A nyctitheriid insectivore (Eulipotyphla, Mammalia) of Asian affinity from the early Eocene of India

Abstract

ABSTRACT A new nyctitheriid (Indonyctia cambayensis gen. et sp. nov.) is described from an early Eocene (~55 Ma) marginal marine sequence (Cambay Shale) at Vastan Lignite Mine, Gujarat, western India. The new taxon is diagnosed by a unique combination of several characters including a single-rooted p2; a p4 with a tiny paraconid at the base but without a metaconid; weakly developed talonid basin; reduced p3 relative to p2 and p4; molar trigonid wider and much higher than talonid; hypoconulid nearly on midline; entoconid positioned anterolingual to hypoconulid; presence of precingulid and a larger and taller protoconid than metaconid. The Asian affinities of the Indian nyctitheriid are indicated by its structurally reduced, premolariform p4 with a weakly developed unicuspid talonid. In several respects, the Indian nyctitheriid is similar to Voltaia, a late Palaeocene taxon from Kazakhstan originally assigned to the Palaeoryctidae but later classified as a nyctitheriid. The presence of a nyctitheriid in the basal Eocene of India suggests a wider palaeogeographic distribution and complex dispersal of this Holarctic family. The Asian affinities of the Indian nyctitheriid suggest faunal exchanges between India and the Mainland Asia possibly via the Dras-Kohistan island arc around the Palaeocene-Eocene boundary (~56 Ma).