CLADYODON, Ow.
Sp. Cladyod,on Lloydii.—In the Memoir on the Triassic Red Sandstones of Warwick, by Murchison and Strickland, published in 1840, in the 2d series of the Geological Transac tions, voL v., a tooth, which is an extremely rare fossil in those English formations, was figured in pl. xxviii., fig. 6.
Having had the opportunity of studying the original speci men and fragments of some others of seemingly the same species from the new red sandstones of Warwick and Leaming ton, the writer recognized the affinity of the reptile possessing those teeth to the thecodont reptiles of the Bristol conglomerate, and indicated what appeared to be a generic modification of dental form by the term Cladyodon.t He subsequently received other specimens of the teeth characterizing this genus, which may be described as being two-edged, sub-compressed ; the sides more or less convex ; the edges more or less sharp, and frequently finely serrate ; the crown slightly bent sideways, the inner side towards the mouth-cavity. The teeth are
sometimes lancet-shaped, through convergence of the edges towards point ; sometimes through one edge being convex and the other concave, the crown is slightly curved or sickle shaped ; sometimes through use, the point is blunted. The enamel is very thin, smooth, showing under the lens a slight longitudinal striation, forming wrinkles. The dentine is dis posed in concentric layers ; it is not labyrinthic ; the base of the tooth shows a conical pulp-cavity. These teeth indicate a Saurian about ten feet in length.
The writer cannot discern any generic, or even good specific distinctions, between the teeth from the Warwickshire keuper, on which in 1840 he founded the genus Cladyodon, and those from the Wirtemberg keuper, on which M. Von Meyer in 1844 founded the genus Belodon. Both are nearly allied to Palmosaurus.
The two following genera are referred provisionally and with doubt to the present order :—