Calamosaurus (meaning "reed lizard") was a genus of small theropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation of the Isle of Wight, England. It is based on two cervical vertebrae (BMNH R901), collected by Reverend William Fox.

History and taxonomy  Edit

Richard Lydekker ran across these bones when cataloguing the Fox collection and named them Calamospondylus, noting their similarity to those of Coelurus. Unfortunately, Calamospondylus had already been coined in 1866 (ironically by Reverend Fox himself, the very man honored in Lydekker's species name). Lydekker renamed it in 1891 to its present title. He also at this time provisionally referred to it a tibia, BMNH R186, which may be from a basal coelurosaurian like a compsognathid.Because of its sparse remains, it has received little attention. Often, it has been synonymized with Calamospondylus as part of a long, confusing taxonomic tangle, although there is no comparable material between the two genera. Modern reviews have regarded it as a dubious theropod, although potentially a valid coelurosaurian.


As a possible basal coelurosaur, Calamosaurus would have been a small, agile, bipedal carnivore. Naish et al. (2001) estimate the living animal would have been around 3–5 meters long (9.8-16.4 feet), with a small head given the build of the neck vertebrae.

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