Anthodon serrarius (Owen 1876) Late Permian ~255 mya, 1.2-1.5 m long was a basal pareiasaur. Derived from a sister to Procolophon and Diadectes Anthodon phylogenetically preceded Stephanospondylus and the toothed turtle, Odontochelys.
Distinct from Procolophon and Diadectes, the skull of Anthodon had anterior-facing nares on a broader skull. Very large quadratojugal "horns" expanded below the orbit. The mandible developed ventral protrusions. The teeth were all smaller and more uniform in size, each with 8 to 15 cusps. The postparietals were fused and, along with the tabulars, were located on the skull roof, as in more primitive diadectomorphs.
More vertebrae were cervicalized. The tail was further shortened.
The scapula developed an acromion process. The manus and pes were smaller with shorter, disc-like phalanges. The ilium was much taller which dropped the pubis and ischium providing a deeper gut. The tarsus was fused.
Small dermal ossicles covered the body. |
