Proterosuchus
Proterosuchus is an extinct genus of archosauriform reptiles that lived during the Early Triassic. It contains three valid species: the type species P. fergusi and the referred species P. alexanderi and P. goweri. All three species lived in what is now South Africa. The genus was named in 1903 by the South African paleontologist Robert Broom. The well-known genus Chasmatosaurus is a junior synonym of Proterosuchus.
Proterosuchus was a mid-sized quadrupedal reptile with a sprawling stance that could reach a length of up to 3.5 meters (11 ft). It had a large head and distinctively hooked snout. It was a predator, which may have hunted prey such as Lystrosaurus. The lifestyle of Proterosuchus remains debated; it may have been terrestrial or it may have been a semiaquatic ambush predator similar to modern crocodiles.
Proterosuchus is one of the earliest members of the clade Archosauriformes, which also includes crocodilians, pterosaurs, and dinosaurs, including birds. It lived in the aftermath of the Permian–Triassic extinction event, the largest known mass extinction in Earth's history.
Proterosuchus was a quadrupedal reptile with a sprawling stance.[1] It could reach a total length of up to 3.5 meters (11 ft).[2] Like most reptiles, Proterosuchus had scaly skin.[3]
Proterosuchus had a proportionally large head and long neck compared to its body.[4][5] The most distinctive characteristic of its head was its strongly hooked snout, formed by a downturned premaxilla.[6] The premaxilla contained up to nine teeth in adults, and the teeth in the snout tip were splayed out to the sides.[6] The jaws of Proterosuchus contained numerous teeth, with up to 9 premaxillary, 31 maxillary, and 28 dentary teeth in each side.[7] The teeth of Proterosuchus were recurved, labiolingually compressed, and serrated, as in most archosauriforms. They were isodont, or all equal in size and shape, in adult individuals, but in juveniles, the teeth were less strongly curved in the back of the jaw.[7]
The skull of Proterosuchus exhibits many features characteristic of its position as a basal archosauriform. It bears a prominent antorbital fenestra, like most archosauriforms. In some specimens, the jugal and quadratojugal contact to complete the ventral margin of the lower temporal fenestra, as in other archosauriforms, but in other specimens, there is a narrow gap between the bones so that the lower temporal bar is incomplete as in non-archosauriform archosauromorphs.[2] The lower jaw bears a small external mandibular fenestra, another characteristic of archosauriforms and their closest relatives.[8]
