An updated generic classification of Cenozoic pleurotomariid gastropods, with new records from the Oligocene and Early Miocene of India

Although taxonomically distinct, the Cenozoic pleurotomariids are the
bottlenecked remnants of the Mesozoic members of the family in terms of
morphology, with only conical forms surviving the end-Cretaceous mass
extinction. Here, we propose an updated classification scheme for the
Cenozoic representatives of this group, based on data from the entire
Cenozoic pleurotomariid fossil record. We consider all conventional as
well as several new characters so that this scheme can readily help to
distinguish Cenozoic pleurotomariid genera. Following the new
classification scheme, a revision of the generic status of Cenozoic
species previously assigned to ‘Pleurotomaria’ Defrance, 1826 is
presented. Only a few Cenozoic pleurotomariid gastropods have been
reported from the Indian subcontinent. Here we report four species from
the Oligocene of the Kutch Basin and the Early Miocene (Burdigalian) of
the Dwarka Basin of Gujarat, western India, of which two are described as
new: Perotrochus bermotiensis n. sp. in the genus Perotrochus Fischer,
1885, and Entemnotrochus kathiawarensis n. sp., Entemnotrochus cf.
bianconii, and Entemnotrochus? sp. 1 in the genus Entemnotrochus Fischer,
1885.