Open Paleo

Sarcosaurus

Andrews, 1921 SAHR-ko-SAWR-us

From Greek 'sarx'/'sarkos' (flesh, meat) + 'sauros' (lizard), meaning 'flesh lizard'.

199.5–192.9 million years ago Sinemurian, Early Jurassic
Early Jurassic stages

Sarcosaurus is a genus of basal neotheropod dinosaur, roughly 3.5 meters (11 ft) long. It lived in what is now England and maybe Ireland and Scotland during the Hettangian-Sinemurian stages of the Early Jurassic, about 199-196 million years ago. Sarcosaurus is one of the earliest known Jurassic theropods, and one of only a handful of theropod genera from this time period. Along with Dracoraptor hanigani it is one of the two described neotheropods from the lowermost Jurassic of the United Kingdom.

Under dispute

Sarcosaurus woodi has been referred to Coelophysoidea or basal Ceratosauria but is recovered as a non-coelophysoid neotheropod on the stem leading to Averostra by Ezcurra and colleagues (2020), followed by Jones (2026).

Diagnosis

  1. Ilium with the main axis of the preacetabular process strongly anteroventrally oriented in lateral view (also in Eoabelisaurus).
  2. Ilium with an only slightly posteriorly projecting ischiadic peduncle (autapomorphy).
  3. Ilium without a laterally exposed ventromedial margin of the brevis fossa, only a short portion of its base exposed (also in Cryolophosaurus).
  4. Ilium with a poorly transversely expanded brevis fossa (also in non-coelophysid neotheropods).
  5. Femur with a dorsolateral trochanter on the proximal end (also in the referred WARMS G667-690 and other non-averostran neotheropods).
  6. Femoral fourth trochanter poorly posteriorly expanded, raised as a low ridge (also in WARMS G667-690, coelophysids, and early ceratosaurians).

Species

Sarcosaurus woodi Andrews, 1921

Type species

Named for S. L. Wood, who found the partial skeleton near Barrow-on-Soar in the Scunthorpe Mudstone of England.

Holotype
BMNH R4840/1 , Natural History Museum
Material
A posterior dorsal vertebra, partial left and right ilia each fused to the proximal portion of their respective pubis, and a left femur missing most of the femoral head and with a severely damaged distal end.
Horizon
Scunthorpe Mudstone Formation, Sinemurian, Early Jurassic , 199.5–192.9 million years ago
Locality
Barrow upon Soar, Leicestershire, United Kingdom

Synonyms

  • Sarcosaurus andrewsi junior subjective

    Erected by von Huene (1932) on NHMUK PV R 3542, a right tibia; Ezcurra and colleagues (2020) regarded it as a subjective junior synonym of Sarcosaurus woodi.

Synonyms of the genus

Name Type Reason
Liassaurus nomen nudum Informal name given to a specimen thought to be Sarcosaurus woodi in 1995; nomen nudum due to lack of overlapping material with the Sarcosaurus woodi holotype.

References

  1. Andrews, C. W. (1921). LVI.—On some remains of a Theropodous dinosaur from the Lower Lias of Barrow-on-Soa. Annals and Magazine of Natural History 8(47): 570-576. Informa UK Limited. doi:10.1080/00222932108632620 andrews1921a
  2. Ezcurra, M. D.; Butler, R. J.; Maidment, S. C. R.; Sansom, I. J.; Meade, L. E.; Radley, J. D. (2020). A revision of the early neotheropod genus Sarcosaurus from the Early Jurassic (Hettangian-Sinemurian) of central England. Zoological Journal of the Linnean Society 191: 113-149. Oxford University Press (OUP). doi:10.1093/zoolinnean/zlaa054

    Redescription and revision of Sarcosaurus; affirms S. woodi as valid (overturning its nomen dubium status), synonymizes S. andrewsi, and recovers it as a non-averostran neotheropod close to Averostra.

    ezcurra2020a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026c
  4. Huene, F. V. (1932). Die fossile Reptil-Ordnung Saurischia, ihre Entwicklung und Geschichte [The fossil reptile order Saurischia, their development and history]. Monographien zur Geologie und Palaeontologie, serie 1 4(1-2): 1-361.

    Erected Sarcosaurus andrewsi on referred material.

    huene1932a