Erythrosuchus

Erythrosuchus (from ἐρυθρός , 'red' and σοῦχος , 'crocodile') is an extinct genus of archosauriform reptiles from the Triassic of South Africa. Remains have been found from the Cynognathus Assemblage Zone of the Beaufort Group in the Karoo of South Africa. In the Late Triassic, the ecological niche left by Erythrosuchus was filled by archosaurs including Saurosuchus and Postosuchus. Erythrosuchus was the largest predator of its time, and was around long. It walked on all fours and had limbs positioned semivertically under its body, unlike the more sprawling gait of most earlier reptiles. Its head was large and theropod-like, reaching a length of , and had sharp, conical teeth. Erythrosuchus was the largest erythrosuchid, but apart from its size, was largely similar in appearance to other related genera. It had a large head and comparatively short neck. One of the few distinguishing features of Erythrosuchus other than its size is the smoothness of the margin of the squamosal, a bone at the rear of the skull. In other erythrosuchids, the margin of this bone projects backward from the skull, giving it a hook-like appearance. In Erythrosuchus, the margin is convex and lacks a hook. Erythrosuchus is known from many specimens, most of which are fragmentary. The holotype, described by Robert Broom in 1905 and known as SAM 905, is poorly preserved. Only small pieces of the limbs, pectoral and pelvic girdles, skull, and a few vertebrae are present in this specimen. A thorough description of the genus was given by German paleontologist Friedrich von Huene in 1911. The fossil material that served as the basis for the description is now housed in the Natural History Museum in London. Like the holotype, it is very fragmentary, and some specimens may even belong to the same individual as SAM 905. One specimen, known as BMNH R 3592, is relatively more complete, with much of the postcranial skeleton intact. Early restorations of the skull of Erythrosuchus depicted it as being tall, similar in appearance to the theropod genus Tyrannosaurus.