A new caenogastropod assemblage from the early Eocene of the Cambay Basin, western India, and its palaeoenvironmental implications

Abstract

In this report we describe 32 species belonging to 26 genera of Caenogastropoda from the early Eocene Cambay Shale of the Cambay Basin, western India. This is the first report of gastropod fossils from this basin, and introduces 24 new species, 2 new subgenera and 3 new genera. The new genera, Eopreangeria, Indobatillaria and Pachycerithium, include new species Eopreangeria mangrolensis, Indobatillaria ismatae and Pachycerithium richardi. The new subgenera are Lyrispina in the genus Lyria and Carinotoma in the genus Apiotoma, including new species Apiotoma (Carinotoma) rammohani. The remaining new species are: Amaurellina cambayensis, Ampullina vastanensis, Amp.? eocenica, Ptychocerithium shamukum, Bittium purnimae, Bi. kamalae, Pseudobellardia sitae, Serratocerithium indicum, Potamides mosaliensis, Pot. shahensis, Sandbergeria khanae, Benthonella prosoclinata, Teinostoma maryae, Natica naroliensis, Involuta? ishwari, Rimella rokeyae, Siphonalia kalpanae, Si. pritilatae, Strepsidura reticulata and Amalda bibhae. A palaeoenvironmental analysis and the diversity–abundance pattern of this fossil fauna provide evidence of an overall marginal marine environment that experienced the Ypresian marine transgression and a gradual increase in marine influence.