Dacentrurus

Dacentrurus ("very sharp tail"), originally known as Omosaurus, was a large stegosaur of the late Jurassic Period (154 - 150 mya). This dinosaur measured around 6 - 10 m (20 - 33 ft) in length. It had paired triangular plates down its spine, with four pairs of spikes on the end of the tail. This configuration closely resembles that of its relative, Kentrosaurus (see also: thagomizer). For unknown reasons, many books claim that Dacentrurus was a small stegosaur, when in fact finds such as a 1.5 m pelvis (measured at the acetabula) suggest that Dacentrurus was among the largest of them.

Discovery and species
When it was described by Richard Owen in 1875 as Omosaurus armatus, it was the first stegosaur ever discovered, although the genus name had to be changed as the name Omosaurus was preoccupied.

Species
Other claimed species of Dacentrurus include D. durobrivensis (included with Lexovisaurus durobrivensis), D. phillipsi (sometimes mistakenly included with Priodontognathus phillipsi, due to having the same species name and a confused history), and D. vetustus (included with Lexovisaurus vetustus).

Distribution
Fossil evidence has been found in Wiltshire and Dorset (including a vertebra ascribed to D. armatus in Weymouth ) in southern England, France and Spain and five more historically recent skeletons from Portugal.


 * Argiles d'Octeville
 * Camadas de Alcobaca
 * El Collado Formation
 * Kimmeridge Clay
 * Unidade Amoreira-Porto Novo
 * Unidade Bombarral
 * ?Unidade Castehanos
 * Unidade Sobral