Page:The Osteology of the Reptiles.pdf/46

28 figures (16–18) and do not require a detailed description. The dentary (d) is always present and dentigerous, except in all Chelonia (Fig. 31, ), some Anomodontia (Fig. 44 ) and Dromasauria, some Theropoda, and the late Pterosauria (Fig. 71 ), Saphaeosaurus, etc.



. 14. Trimerorhachis alleni Case. Temnospondyl skull and mandible: A, right mandible, inner side; B, the same, outer side; C, D, E, sections of mandible as designated; F, skull and mandible, left side; psp, postsplenial; cor, coronoid; icor, intercoronoid; pcor, precoronoid.

The coronoid (cor), extending along the inner margin of the teeth from near the symphysis to the hind end of the dentary on the inner side, possibly composed of two bones in some of the earliest reptiles (Fig. 18), has been restricted to a place at the posterior end of the dentary in later forms (e.g., Fig. 55 ), and may in some cases be absent. In the Plesiosauria (Fig. 25 ) it still retains its ancient character, even entering into the symphysis in some cases. In the Dinosauria, or some of them at least, it also extends far forward, or there may perhaps be a distinct bone in front, the intercoronoid