Metriacanthosaurus

 Metriacanthosaurus (meaning "moderately-spined lizard") is a genus of metriacanthosaurid dinosaur from the upper Oxford Clay of England, dating to the Late Jurassic period, about 160 million years ago (lower Oxfordian).

Metriacanthosaurus
Temporal range: Oxfordian160 Ma 
PreꞒ
O
S
D
C
P
T
J
K
Pg
N
Metriacanthosaurus.jpg
Life restoration
Scientific classificatione
Kingdom:Animalia
Phylum:Chordata
Clade:Dinosauria
Clade:Saurischia
Clade:Theropoda
Family:Metriacanthosauridae
Subfamily:Metriacanthosaurinae
Genus:Metriacanthosaurus
Walker, 1964
Type species
Megalosaurus parkeri
von Huene, 1923
Species
  • Metriacanthosaurus parkeri (von Huene, 1923)
Synonyms
  • Megalosaurus parkeri von Huene, 1923
  • Altispinax parkeri (von Huene, 1923)

History of discoveryEdit

In 1923, German paleontologist Friedrich von Huene wrote a paper on Jurassic and Cretaceous European carnivorous dinosaurs. In this paper, he examined a specimen (OUM J.12144) including an incomplete hip, a leg bone, and part of a backbone, assigning it to a new species of MegalosaurusMegalosaurus parkeri. The specific name honours W. Parker who in the nineteenth century had collected the fossils near Jordan's Cliff at Weymouth.[1]These bones were from the Oxford Clay Formation, which dates to the Upper Jurassic.[2]

In 1932, however, von Huene concluded it was a species of AltispinaxA. parkeri.[3]

In 1964, scientist Alick Walker decided these fossils were too different from Altispinax, as they lacked the long vertebral spines, and named the new genus Metriacanthosaurus.[4]The generic name is derived from Greek metrikos, "moderate", and akantha, "spine". Metriacanthosaurus thus gets its name from its vertebrae, which are taller than typical carnosaurs, like Allosaurus, but lower than other high-spined dinosaurs like Acrocanthosaurus.

DescriptionEdit

Metriacanthosaurus was a medium-sized theropod with a femur length of 80 cm (31 in). Gregory S. Paul in 1988 estimated its weight at 1 tonne (1.1 short tons).[5] Thomas Holtz gave a length of 8 meters (26.2 feet).[6]Metriacanthosaurus was named for the height of its neural spines, which are actually not overly tall for theropods.[2] They are similar to other theropods such as MegalosaurusSinraptor, and Ceratosaurus in being 1.5 times the height of the centrum.[7]

ClassificationEdit

Originally named as a species of Megalosaurus in MegalosauridaeMetriacanthosaurus has since been reclassified in Metriacanthosauridae. It is thought to be related to genera such as Yangchuanosaurus, and in 1988 Paul synonymized the two genera. However, a 2007 review of British dinosaurs by Darren Naishand David Martill defending keeping the two genera taxonomically separate.[2]Metriacanthosaurus is considered a member of the subfamily Metriacanthosaurinae.[8]

Below is a simplified cladogram of Tetanuraeby Matthew Carrano et al. (2012).[8]

Metriacanthosauridae

Yangchuanosaurus zigongensis

CV 00214

Yangchuanosaurus shangyouensis

Metriacanthosaurinae

Shidaisaurus

Metriacanthosaurus

"Sinraptor" hepingensis

Sinraptor dongi

Siamotyrannus