met-ree-a-kan-tho-sore-us
Pronunciation guide: Natural History Museum
"moderately spined lizard"
To scale
Scale in metersOutline: typical theropod shape
The evidence
Today
160 million years ago
It probably hunted on land near the shallow sea that laid down the Oxford Clay. Dinosaurs from these rocks include Eustreptospondylus, Cetiosauriscus and Loricatosaurus.
Field notes
Metriacanthosaurus was a large two-legged predator estimated at about 8.2 meters (27 feet) long. It is known from an incomplete skeleton, so its total length is a reconstruction rather than a measurement of a complete animal. Its name refers to the spines on its backbones; these were not unusually tall compared with many other theropods.
It lived in the Late Jurassic in what is now England. Its bones come from the Oxford Clay.
Its bones were first placed in Megalosaurus. Walker gave it its own genus in 1964. It gave its name to the metriacanthosaurids, a family that also includes Sinraptor and Yangchuanosaurus.
From the specimen
The name Metriacanthosaurus parkeri is anchored to a holotype, the reference specimen for the species. The partial skeleton, OUMNH J.12144, is held at Oxford University Museum of Natural History. It includes vertebrae, pelvic bones and hindlimb bones, rather than a complete skeleton with a skull. Oxford specimen record
The Oxford specimen record places a tail vertebra from that skeleton at Jordan Cliff, Overcombe, near Weymouth in Dorset. Research identifies the rocks as the Weymouth Member of the Oxford Clay. The bones were first assigned to Megalosaurus; Walker established Metriacanthosaurus as a separate genus in 1964. That is a naming date, not a discovery date. Research review, pp. 495, 502
All three were large meat-eating theropods. Family relationships and the completeness of their fossils are more useful comparisons than a precise size ranking.
An allosaurid from the Late Jurassic, especially well known from North America. Its skull preserves distinctive horns above the eyes. Metriacanthosaurus belongs to a different family, Metriacanthosauridae, and its missing skull cannot show whether it had similar ornaments.
A fellow metriacanthosaurid from China. Nearly complete specimens of Yangchuanosaurus shangyouensis give a much fuller picture of its anatomy. These fossils help with comparisons, but do not establish the exact shape of the missing parts of Metriacanthosaurus.
Sources: Natural History Museum: Allosaurus; Zou and colleagues, 2025. Relationships within the family remain under study; similarity does not make these animals the same genus.
Field gallery
Scenes reconstructed from the available fossil evidence.
Found in the same rock formations
A rock formation can hold fossils laid down millions of years apart, so not every animal here met Metriacanthosaurus.
The evidence
Which parts of the picture come from its own bones, and which come from its relatives.
The research behind what we know of Metriacanthosaurus
Named it
Separated the partial skeleton from Megalosaurus and established Metriacanthosaurus as its own genus.
Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 248: 53-134
Read the paper : Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs (opens in a new tab)Family tree
Placed Metriacanthosaurus in the same family as Sinraptor and Yangchuanosaurus through a broad comparison of theropod skeletons.
The phylogeny of Tetanurae (Dinosauria: Theropoda). Journal of Systematic Palaeontology 10: 211-300
Read the paper : The phylogeny of Tetanurae (Dinosauria: Theropoda) (opens in a new tab)Close relative
Described Yuanmouraptor, an early member of the same family, and tested how the family's members fit into the theropod family tree.
A new metriacanthosaurid theropod dinosaur from the Middle Jurassic of Yunnan Province, China. PeerJ 13: e19218
Read the paper : A new metriacanthosaurid theropod dinosaur from the Middle Jurassic of Yunnan Province, China (opens in a new tab)Other members of Metriacanthosauridae
Sources: Wikidata
