Selachian faunas from the earliest Cretaceous Purbeck Group of Dorset, southern England.

Abstract

Abundant selachian remains have been recovered from a number of horizons through the Purbeck Group at Durlston Bay, Lulworth Cove and Stair Hole in southern England. The remains, primarily teeth, but additionally fin spines and dermal denticles, belong to selachians from two major groups, the Hybodontoidea and the Rhinobatoidei. The assemblage of hybodont sharks is quite diverse, comprising six species from the four genera ‘Hybodus’, Egertonodus, Polyacrodus and Lonchidion. The rhinobatoid rays include two species, one belonging to the genus Belemnobatis and another, larger, indeterminate ray. Within the Purbeck fauna, two species are new: Lonchidion inflexum sp. nov. and Belemnobatis variabilis sp. nov. Within the entirely non-marine succession of the Purbeck Group, the beds containing ray teeth also contain molluscs indicative of more saline intervals. In all of the sampled beds, the hybodont faunas recovered were relatively homogenous