Occurrence of the genus Eoconuloides Cole and Bermudez 1944 in Rajasthan, India and its paleobiogeographic significance

摘要

The two known species of the genus Eoconuloides Cole and Bermudez are recorded and described for the first time from Eocene strata of the Indian subcontinent. Hitherto, the genus Eoconuloides represented by Eoconuloides parvulus (Cushman) and E. wellsi Cole and Bermudez was believed to be restricted to the Caribbean region. The presence of E. parvulus in the Jaisalmer basin and E. wellsi in the Bikaner basin of Rajasthan, northwestern India, is significant, as it negates the endemism of these larger foraminiferal species within the American province. The age determination of the Eocene rocks of Rajasthan was based on the ranges and assemblages of planktonic foraminifers and the presence and distribution of larger foraminifera. In Rajasthan, the first appearance datum of E. parvulus and E. wellsi is approximately three to four million years later than the Caribbean region. The paleobiogeographic implication of the occurrence of Eoconuloides in the Caribbean and northwestern India is discussed and localities where Eoconuloides may be found in the future are indicated.