Eustreptospondylus
yoo-STREP-toh-SPON-dih-lus
"well-curved vertebrae"
- Lived
- 165 to 162 million years ago, Middle Jurassic
- Diet
- Carnivore
- Length
- about 7 m (23 ft)
- Group
- Theropods, Megalosauridae
- Found in
- United Kingdom
- Named by
- Walker 1964
Size comparison
To scale
Scale in metersOutline: typical theropod shape
Where its fossils were found
The evidence
Today
165 million years ago
Habitat
Islands bordered by warm, shallow seas in Europe. Loricatosaurus and Cetiosauriscus lived on the nearby land.
Field notes
About Eustreptospondylus
What it was like
Eustreptospondylus was a two-legged meat eater about 7 meters (23 feet) long, a relative of Megalosaurus. The known skeleton seems to be a young animal, so adults were probably larger.
It had a long skull with sharp, curved teeth, short strong arms and a long tail.
Its world
It lived in the Middle Jurassic, about 165 to 162 million years ago, in what is now England. Europe was then a scatter of islands in a warm, shallow sea.
Its skeleton comes from the Oxford Clay, a rock laid down in that sea, so the animal probably washed out from a nearby shore. It shared its world with the stegosaur Loricatosaurus and the sauropod Cetiosauriscus.
How it was found
Walker named Eustreptospondylus in 1964, though the skeleton had been dug up long before and first placed in Megalosaurus. It is one of the most complete large meat eaters from Europe.
Field gallery
More views of Eustreptospondylus
Scenes reconstructed from the available fossil evidence.
1 of 3
Lived alongside
Found in the same rock formations
A rock formation can hold fossils laid down millions of years apart, so not every animal here met Eustreptospondylus.
The evidence
The science behind Eustreptospondylus
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- An incomplete skeleton preserves skull bones, vertebrae and limb bones.
- The jaw joint has an angled groove that probably let the back of the lower jaw spread outward as the mouth opened.
Borrowed from relatives
- Missing parts are restored by comparison with Megalosaurus and other megalosaurids.
Still unknown
- The size and proportions of a fully grown adult.
- Its skin covering and color.
- Whether it regularly fed along the shore.
Discovery timeline
- 1964Named itWalker
- 2006Full descriptionSadleir, Barrett & Powell
- 2010SkullMolnar
- 2012Family treeCarrano, Benson & Sampson
Key papers
The research behind what we know of Eustreptospondylus
Named it
Established Eustreptospondylus as a separate genus for a skeleton previously assigned to Megalosaurus.
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)Full description
Provided a detailed account of the skeleton and compared its anatomy and relationships with other early large theropods.
The Anatomy and Systematics of Eustreptospondylus Oxoniensis, A Theropod Dinosaur from the Middle Jurassic of Oxfordshire, England. Monographs of the Palaeontographical Society 160: 1-82
Read the paper : The Anatomy and Systematics of Eustreptospondylus Oxoniensis, A Theropod Dinosaur from the Middle Jurassic of Oxfordshire, England (opens in a new tab)Skull
Highlighted the angled jaw joint and its possible role in spreading the lower jaw as the mouth opened.
A Review of “The Anatomy and Systematics of Eustreptospondylus Oxoniensis , a Theropod Dinosaur From the Middle Jurassic Of Oxfordshire, England”, by R. Sadleir, P. M. Barrett, and H. P. Powell, 2008. Monograph of the Palaeontographical Society, London, 82 pp., 20 Pl., £110.00, ISSN 0269-3445. Journal of Vertebrate Paleontology 30: 306-306
Read the paper : A Review of “The Anatomy and Systematics of Eustreptospondylus Oxoniensis , a Theropod Dinosaur From the Middle Jurassic Of Oxfordshire, England”, by R. Sadleir, P. M. Barrett, and H. P. Powell, 2008. Monograph of the Palaeontographical Society, London, 82 pp., 20 Pl., £110.00, ISSN 0269-3445. (opens in a new tab)Family tree
Compared early large theropods and placed Eustreptospondylus within the megalosaurid branch of their family tree.
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 relatives
Other members of Megalosauridae
Sources: Wikidata