Calamosaurus

Taxobox|
name = "Calamosaurus"
status = fossil
fossil_range = Early Cretaceous
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Dinosauria
ordo = Saurischia
subordo = Theropoda
unranked_familia = ?Coelurosauria
genus = "Calamosaurus"
genus_authority = Lydekker, 1891
species = "C. foxii"
species authority = (Lydekker, 1889) (originally "Calamospondylus")
binomial = "Calamosaurus foxi"
binomial authority = Lydekker, 1891

"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

Richard Lydekker ran across these bones when cataloguing the Fox collection and named them "Calamospondylus", noting their similarity to those of "Coelurus".Lydekker. R. (1889). On a coelurid dinosaur from the Wealden. "Geological Magazine" 6:119-121.] Unfortunately, "Calamospondylus" had already been coined in 1866 (ironically by Reverend Fox himself, the very man honored in Lydekker's species name).Fox, W.D. in Anonymous. (1866) Another Wealden reptile. "Athenaeum" 2014:740.] Lydekker renamed it in 1891 to its present title.Lydekker. R. (1891). On certain ornithosaurian and dinosaurian remains. "Quartely Journal of the Geological Society of London" 47:41-44.] He also at this time provisionally referred to it a tibia, BMNH R186, which may be from a basal coelurosaurian like a compsognathid.Naish, D., Hutt, S., and Martill, D.M. (2001). Saurischian dinosaurs 2: theropods. In: Martill, D.M., and Naish, D. (eds.). "Dinosaurs of the Isle of Wight." The Palaeontological Association:London, 242-309. ISBN 0-901707-72-2]

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,Swinton, W.E. (1936). The dinosaurs of the Isle of Wight. "Proceedings of the Geologists' Association" 47(3):204-220.] Romer, A.S. (1956). "Osteology of the Reptiles." University of Chicago Press:Chicago, 1-772. ISBN 0-89464985-X] Steel, R. (1970). Part 14. Saurischia. "Handbuch der Paläoherpetologie/Encyclopedia of Paleoherpetology." Part 14. Gustav Fischer Verlag:Stuttgart, 1-87.] although there is no comparable material between the two genera. Modern reviews have regarded it as a dubious theropod,Norman, D.B. (1990). Problematic theropoda: "coelurosaurs". In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). "The Dinosauria". University of California Press:Berkeley, 280-305. ISBN 0-520-06727-4.] Holtz Jr., T.R., Molnar, R.E., and Currie, P.J. (2004). Basal Tetanurae. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). "The Dinosauria" (second edition). University of California Press:Berkeley, 71-110. ISBN 0-520-24209-2.] although potentially a valid coelurosaurian.

Paleobiology

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.

References