Scythosuchus
Scythosuchus is an extinct genus of rauisuchid. Remains have been found from Olenekian-age Lower Triassic beds in Russia, hence the name meaning 'Scythian crocodile'.
Discovery
The type and only species is S. basileus, described in 1999. Scythosuchus was between 2 and 3 metres long, and relatively heavily built. It is known from a partial skull, much of the spine, a fragment of the humerus and most of the hind leg and foot. It may have been the same animal as Tsylmosuchus donensis.Features
Skull
The skull material known is fragmentary, with a few parts of the cranium, the maxilla and some of the rostrum, and several examples of teeth. The maxilla is long, as is the preorbital fenestra just above it, and has a break indicating that there was probably a large medial process. The whole snout was slightly elongated but quite narrow. The blade-like teeth are laterally compressed and serrated, with a slight backwards curve, and would have been excellent for slicing through flesh, clearly indicating that Scythosuchus was a carnivore like other rauisuchids. The cranium is relatively small, and the postorbital bone is stout and thick with some rugosities in the central area. All of the squamosal processes are heavy and well-developed. The lower jaw is thick and has very expanded articular areas, possibly indicating a powerful bite as it would have been quite difficult for a struggling prey animal to break free.Vertebrae
The cervical vertebrae are slightly elongated, with the centra constricted between the wide articular surfaces. These articular surfaces are rounded. The zygapophyses have large articular surfaces oriented obliquely. The centra are approximately 1.2 times as long as they are high, and the neural spines are also very low and poorly developed, with a slightly widened and thickened tip making them top-heavy. As the vertebrae move back from the skull, the neural spines grow thicker, heavier and more rugose at the dorsal ends until they resemble osteoderms.The thoracic vertebrae look quite similar to the cervical vertebrae, with lengthened centra and heavy rugose tips to their neural spines. However, the neural spines themselves are much longer than those on the cervical vertebrae, and by the posterior thoracic vertebrae are also relatively narrow. The centra have perfectly round articular facets and are slightly constricted in the centre.
The caudal vertebrae also have lengthened centra, especially at the posterior end of the tail, and these grow longer and longer posteriorly. The articular facets are also tall and narrow, rather than perfectly round. The neural spines are much less rugose and heavy at the tips, but are short and thick, with a slight tilt backwards, and located on the posterior part of the centra.