Proterosuchus is a proterosuchid reptile from the Early Triassic of South Africa and China. It was named in 1903 by Robert Broom. It was one of the earliest archosaurs, a clade of reptiles that includes crocodilians and dinosaurs.
Physiology
Proterosuchus had a build very similar to modern crocodylomorphs, with a broad body, short legs, a long tail, and a head with large jaws. Perhaps the most defining trait of this reptile was its notched, hook-like upper jaw. Its body would have been covered in scaly skin.
Diet
Proterosuchus was a predator, feeding on anomodonts (as well as any other mid-sized creature that got near the water). Its conical teeth were used for getting a hold of struggling prey, and its notched upper jaw would have helped in capturing them as well.
Ecology
Like the crocodylomorphs it was convergent upon, Proterosuchus is thought to have been an aquatic ambush predator, lying in wait near the surface of the water before speeding towards its prey (using its tail to propel itself through the water), biting them, dragging them into the water, and drowning them. This hunting method means that it would have spent its time in one environment for most of its life; this serves as a great energy conservation method. As well as this, its stout limbs allowed for terrestrial locomotion (which was usually done in a similar manner to the high walk of many modern crocodilians); in fact, this amphibious style allowed for many thermoregulatory benefits, as the animal could either sunbathe or cool off in the water. A comparison of its sclerotic rings (large rings in the eye sockets that determine eye size) to those of modern reptiles and birds indicates that it was cathemeral (active throughout the day and night during short intervals); this sort of lifestyle benefitted the animal, as it lived somewhat close to the South Pole, and would have experienced different lighting conditions than others.
In popular culture
Proterosuchus was featured in the 3rd episode of the 2005 documentary Walking with Monsters, where it was shown as behaving similarly to Nile crocodiles, hunting Lystrosaurus that were crossing a large river. As well as this, it was referred to as "Chasmatosaurus", which was recognized as a different genus of proterosuchid, right before being lumped into the Proterosuchus genus.