The Dinosaurs - Aristosuchus, an Isle of Wight tyrannosauroid?

Aristosuchus, an Isle of Wight tyrannosauroid?

Meaning

Superior Crocodile

Length

2m (6 feet)

Classification

Theropoda,
Coelurosauria,
Tyrannosauroidea Osborn, 1906 (vide Walker, 1964)

Aristosuchus pusillus (Owen, 1976)

Locations

Known from the Wessex Formation, so try Brighstone bay.

A small theropod, Aristosuchus probably hunted the smaller animals in the Wessex Formation.

Aristosuchus is known from a sacrum, a pubis, a femur and a few vertebrae. There is a pair of unguals, BMNH R179 and R899, which may be from Aristosuchus.

The sacrum is 120 mm long, and the five sacral vertebrae are unfused, indicating that the specimen had yet to reach full maturity. The centra are concave ventrally when viewed laterally: a low median ridge is present on the ventral surface of the fourth centrum. Intervertebral foramina, 6 mm in width, are present between some of the vertebra.

The femur of Aristosuchus has a wing-like anterior trochanter and an incredibly reduced fourth trochanter.

Although Aristosuchus is usually referred to as a compsognathid, those alleged compsognathid characters () are also present in tyrannosaurids, which are well represented on the Isle of Wight by Calamosaurus and Eotyrannus, so we’re placing it in that group here.

Material is rare, so please report it if you find some…

NAISH, D., HUTT, S. and MARTILL, D. M. 2001. Saurichian (sic) dinosaurs 2: theropods. In MARTILL, D. M. and NAISH, D (eds). Dinosaurs of the Isle of Wight. The Palaeontological Association. Field Guide to Fossils 10, 242-309.

NAISH, D. 2002. The historical taxonomy of the Lower Cretaceous theropods (Dinosauria) Calamospondylus and Aristosuchus from the Isle of Wight. Proceedings of the Geologists’ Association, 113, 153–163​

NAISH, D. 2011. Theropod dinosaurs. In Batten, D. J. (ed.) English Wealden Fossils. The Palaeontological Association (London), pp. 526-559.