Vertebrae and ribs of various reptile groups, Samuel Wendell Williston, 1925

Illustration of vertebrae and ribs of various reptile groups from the osteology of the reptiles (1925) fig. 86. Vertebrae and ribs: a, clidastes (mosasauria), posterior cervical vertebra, from behind; b, cymbospondylus (ichthyosauria), anterior dorsal vertebra, from the side, after merriam; c, ichthyosaurus (ichthyosauria), middle dorsal vertebra, from the side (after broili); d, dimetrodori (theromorpha), anterior dorsal rib; e, diadectes (cotylosauria), anterior dorsal rib. Date: 1925. The Osteology of the Reptiles p112