Dacentrurus

Animalia

Dacentrurus Temporal range: Late Jurassic, 154–150 Ma PreЄ Є O S D C P T J K Pg N ↓
Holotype specimen, London
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Superorder:	Dinosauria
Order:	†Ornithischia
Suborder:	†Stegosauria
Family:	†Stegosauridae
Genus:	†Dacentrurus Lucas, 1902
Species:	†D. armatus
Binomial name
Dacentrurus armatus (Owen, 1875 [originally Omosaurus])
Synonyms
Omosaurus armatus Owen, 1875 (preoccupied)

Dacentrurus ("very sharp tail"), originally known as Omosaurus, was a large stegosaur of the Late Jurassic Period (154 - 150 mya).

Description

Life restoration of Dacentrurus armatus

This dinosaur measured around 8 metres (26 ft) in length.^[1] 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). Many books claim that Dacentrurus was a small stegosaur, when in fact finds such as a 1.5 metres (4.9 ft) pelvis (measured at the acetabula) suggest that Dacentrurus was among the largest of them. Although Dacentrurus is considered to have the same proportions as a Stegosaurus, Dacentrurus' plate and spike configuration is known to be rather different, as Dacentrurus has both two rows of small plates and two rows of longer spines along its back.^[2] Its closest relative within Stegosauria is Miragaia, and the two are united in the subfamily Dacentrurinae.

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

Holotype of Dacentrurus armatus, from Owen's 1875 monograph

Other proposed 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^[3]) in southern England, France and Spain and five more historically recent skeletons from Portugal.

• Argiles d'Octeville^[4]
• Camadas de Alcobaça^[4]
• Villar del Arzobispo Formation^[4]
• Kimmeridge Clay^[4]
• Unidade Amoreira-Porto Novo^[4]
• Unidade Bombarral^[4]
•  ?Unidade Castehanos^[4]
• Unidade Sobral^[4]

Eggs attributed to Dacentrurus have also been discovered in Portugal.

Footnotes

1. ^ Holtz, Thomas R. Jr. (2008) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages Supplementary Information
2. ^ Lessem, Don (2003). Scholastic Dinosaurs A-Z. Scholastic Inc.. pp. 67. ISBN 0-439-16591-1. 
3. ^ Galton PM.(1985)"British plated dinosaurs (Ornithischia, Stegosauridae) Journal of Verebrate Paleontology, 5, 211-254
4. ^ ^{a b c d e f g h} Galton, Peter M.; Upchurch, Paul (2004). "Stegosauria (Table 16.1)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 344-345. ISBN 0-520-24209-2.

References

• Benton MJ, Spencer PS (1995). Fossil Reptiles of Great Britain. Chapman & Hall. ISBN 0-412-62040-5. 

External links

Dinosaurs portal

• Natural History Museum site on Dacentrurus
• dulops.net on Dacentrurus (Spanish)
• Discussion on the claimed small size of Dacentrurus