Lystrosaurus is a lystrosaurid therapsid synapsid from the Lopingian-Early Triassic of South Africa, Antarctica, and India. It was named in 1870 by Edward Drinker Cope. It was the most common anomodont therapsid synapsid in the Early Triassic, and it was one of the most notable disaster taxa, surviving the cataclysmic extinction event of the Permian.
Physiology[]
Lystrosaurus was an anomodont with 4 legs, a regularly-shaped body, a short tail, and a big head with a small beak and two downwards-facing tusks. Its body would have been covered in smooth skin.
Diet[]
Lystrosaurus was an herbivore, feeding on seeds, leaves, roots, and tubers. Behind its horny beak, it had a horny secondary mouth roof used for grinding up food; as well as this, its tusks were used for digging up roots and tubers.
Ecology[]
Due to having very little pelvic vertebrae, Lystrosaurus assumed a semi-sprawling gait; however, its forelimbs were massive, and so, it is thought to have been able to burrow into the ground. As well as this, once it sheared off pieces of vegetation, it would chew with its jaw moving back and forth, grinding up its food. Why it managed to survive the Permian extinction has remained a mystery for a long time; possible (and plausible) theories included having anatomical features leaving it capable of coping with stale air, being relatively unspecialized, having barely any large predators to prey on it, being semi-aquatic (which was disproved, as it was a primarily terrestrial anomodont, and contemporary Early Triassic amphibians weren't as common as it), or just being extremely lucky. Now, recent findings have put forth the most accepted theory; it had a short lifespan (15 years), so it bred as quickly and as commonly as possible, procreating lots of individuals.
In popular culture[]
Lystrosaurus was featured in the 3rd episode of the 2005 documentary Walking with Monsters, where it is shown as evolving from Diictodon over a course of 9.8 (or 4.8) million years. As well as this, it is shown as a herd animal capable of not getting completely destroyed by dangerous events such as Euchambersia ambushes or Proterosuchus attacks; it is only later in the Triassic that it, along with all other large dicynodonts, gets outcompeted by the later dinosaurs.