On Cervical and Dorsal Vertebræ of Crocodilus cantabrigiensis (Seeley) from the Cambridge Upper Greensand

Abstract

At rare intervals remains of a procœlous Crocodile have been found in the Cambridge Greensand, which, in cranial bones, smaller limb-bones, and vertebræ, approximates so closely to the living crocodilian type as only to indicate a distinct species. This species was recorded in the index to the Secondary Reptiles in the Woodwardian Museum as Crocodilus cantabrigiensis ; and I now offer some account of its characters. A cervical vertebra shows the centrum to be inclined slightly forward, like the vertebræ of Lizards; the narrowness and small size of the parapophysis shows it to have been an early cervical, probably the third or fourth. The centrum is ⅝ inch long, and is divided from the neural arch by a distinct suture, which runs parallel to the base of the centrum, and so is inclined to the articular faces. In front the centrum has a quadrate aspect (fig. 1), the two neurapophyses widening inward to make the upper corners of the articular face angular, while the parapophyses form corresponding lower angles. The articular face of the centrum is about seven-sixteenths inch broad, widest in the upper part, and about six-sixteenths inch high. Around the margin is a narrow flattened articular area, within which is a moderately excavated cup, which only differs from that of other Crocodiles in being less deep. The neurapophyses rise vertically above the centrum, and terminate back and front in the zygapophysial facets at a height