Image:Procolophon BW.jpgProcolophon was a genus of lizard-like procolophonid reptiles with at least eight species that persisted through the Permian–Triassic extinction event, but became extinct in the later Triassic. The vertebrae were robust with a rounded rib cage composed of many small weak ribs. Legs were short, thickly built with short phalanges; this suggests an animal that burrowed and did not run fast.