From Wikipedia, the free encyclopedia
Lystrosaurus (meaning 'shovel reptile', pronounced list-row-sore-uss) was an early Triassic therapsid. It was a common synapsid, a group of animals with mixed mammalian and reptilian traits. More specifically, it was a dicynodont (which means "having two dog-teeth"). Lystrosaurs were medium-sized (about a meter long) herbivorous creatures roughly the size of pigs, with very stout limbs. They had two long teeth protruding from their upper jaws. Originally they were thought to be amphibious, a sort of small reptilian hippopotamus, but some more recent evidence indicates that they lived in arid environments.
Lystrosaurus is notable for dominating land during the early Triassic Period, found on every continent to the exclusion of other vertebrates, for millions of years. Due to presumably little more than good fortune, the genus survived the end-Permian extinction and went on to thrive on land. While it is possible that adaptations, such as an ability to survive on little food, aided its survival, the reason may be no more than sheer luck. Whatever the circumstances, it became the most common (indeed only common) land vertebrate of the early Triassic, in a very unusual ecology, not seen again until the arrival of agricultural monocultures.
