Anoplosaurus

Taxobox|
name = "Anoplosaurus"
status = fossil
fossil_range = Lower Cretaceous
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Dinosauria
ordo = Ornithischia
subordo = Thyreophora
infraordo = Ankylosauria
familia = ?Nodosauridae
genus = "Anoplosaurus"
binomial = "Anoplosaurus curtonotus"
binomial_authority = Seeley, 1879

"Anoplosaurus" (meaning "unarmored or unarmed lizard") was a genus of possible nodosaurid dinosaur, from the late Albian-age Lower Cretaceous Cambridge Greensand of Cambridgeshire, England. It has been classified with the armored dinosaurs and ornithopods, but current thought has been in agreement with the "armored dinosaur" interpretation.

History

Harry Govier Seeley named this genus in 1879 for a partial postcranial skeleton, composed of dentary fragments, numerous vertebra from the neck, back, and sacrum, parts of the pectoral girdle, humerus fragments, part of the left femur, left tibia, foot bones, ribs, and other fragments. He regarded it as possibly juvenile, due to its small size.Seeley, H.G. (1879). On the Dinosauria of the Cambridge Greensand. "Quarterly Journal of the Geological Society of London" 35:591-635.] Other workers began to see it as an armored dinosaur,Zittel, K.A. (1893). "Traité de Paléontologie III, Paléozoologie, Vertebrata (Pisces, Amphibia, Reptilia, Aves)." Paris:Doin, xii-894. [French] ] Hennig, E. (1915). "Kentrosaurus aethiopicus". Die Stegosaurier-Funde von Tendaguru Deutsch-Ostravrika. II. Historisch-systematische Einführung. "Palaeontographica Supplement" 7:103-253. [German] ] until 1923 when Franz Nopcsa suggested that some of the remains belonged to a camptosaur, and other remains, which he removed from the genus, belonged to "Acanthopholis".Nopcsa, F. (1923). Notes on the British dinosaurs, Part IV: "Acanthopholis". "Geological Magazine" 60193-199.] This suggestion was followed (with modifications as iguanodontian taxonomy changed over the years),Norman, D.B., and Weishampel, D.B. (1990). Iguanodontidae and related ornithopods. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). "The Dinosauria." University of California Press:Berkeley, 510-533. ISBN 0-520-06727-4.] Suberbiola and Barrett reexamined the material. They wrote that the material all belonged to a primitive nodosaurid, the lack of armor possibly due to the young age of the animal at death.Suberbiola, X.-P., and Barrett, P.M. (1999). A systematic review of ankylosaurian dinosaur remains from the Albian of England. "Special Papers in Palaeontology" 60:177-208.] Reviews since then have followed this interpretation of the genus as an armored dinosaur.Carpenter, K. (2001). Phylogenetic analysis of the Ankylosauria. In: Carpenter, K. (ed.). "The Armored Dinosaurs." Indiana University Press:Bloomington 455-483. ISBN 0-253-33964-2 ( [https://scientists.dmns.org/sites/kencarpenter/PDFs%20of%20publications/Anki%20Phylogenetics.pdf PDF is 1744 kb] )] Vickaryous, M.K., Maryańska, T., and Weishampel, D.B., (2004). Ankylosauria. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria (second edition). University of California Press:Berkeley 363-392. ISBN 0-520-24209-2]

A second species, "A. major", was named by Seeley in 1879 for a neck vertebra and three partial caudal vertebrae he removed from "Acanthopholis stereocercus", from the same formation as the type species. This species now appears to be chimeric, the neck vertebra coming from an ankylosaur, the caudals from an indeterminate iguanodont.Norman, D.B. 2004. Basal Iguanodontia. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria (second edition). University of California Press:Berkeley, 413-437. ISBN 0-520-24209-2.]

Palaeobiology

As a possible nodosaurid, "Anoplosaurus" would have been a quadrupedal, low-slung herbivore, with armour on its body for protection.

References