The Dinosaurs - Calamosaurus, an Isle of Wight tyrannosauroid


an Isle of Wight tyrannosauroid

Calamosaurus material


Reed lizard




Osborn, 1906 (vide Walker, 1964)

‘Calamosaurus foxi’ Lydekker, 1891


Known from the Wessex Formation, so try Brighstone bay.

Calamosaurus is known from two articulated cervical vertebrae, with well-developed zygapophyses and laterally projecting diapophyses that are square in cross section, which may be the diagnostic feature of the species. The articular faces of the vertebrae are angled so that the ventral border of the posterior end of the vertebrae is lower than the anterior end. There are no epipophyses and there are excavations on the neural arch, dorsal to the neural canal, on both the anterior and posterior ends of the vertebra, and on the lateral sides of the neural arch. The prezygapophyses have dorsomedially facing flat facets, while the postzygapophyses have flat facets ventrolaterally.

Dinosaur Farm Museum (now Dinosaur Expeditions) ran a dig to excavate some Calamosaurus material a number of years ago, but information has yet to appear. Otherwise, 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. 2011. Theropod dinosaurs. In Batten, D. J. (ed.) English Wealden Fossils. The Palaeontological Association (London), pp. 526-559.