Pareiasauridae

The Pareiasaurs - Family Pareiasauridae - are a clade of medium-sized to large herbivorous anapsid reptiles that flourished during the Permian period.

Their build was quite stocky, often with rather short tails and small heads. These ungainly-looking animals had very large bodies, ranging from 60 to 300 cm long, and weights of 600 kg would not been unusual. They also had strong limbs, broad feet, and short tails. They were protected with bony scutes (osteoderms) set in the skin, as a defense against predators. Their heavy skulls were ornamented with multiple knobs and ridges.

The leaf-shaped multi-cusped teeth resemble those of iguanas, caseids, and other reptilian herbivores. This dentition, together with the deep capacious body, which could have housed an extensive digestive tract, indicate that these fearsome-looking animals were herbivores.

Lee (1997) has argued that pareiasaurs evolved into turtles. They had turtle-like skull features, and in several genera the scutes had developed into bony plates, possibly the precursors of a turtle shell. However, critics have pointed out problems in this view, such as the lack of homology between pareiasaur scutes and the turtle shell.