Streptospondylus

Meyer, 1832 STREP-to-SPON-di-lus

From Ancient Greek streptós, "twisted", combined with Greek spóndulos, "vertebra" — means "twisted vertebra"

165.3–154.8 million years ago Callovian–Oxfordian, Middle Jurassic–Late Jurassic

Middle Jurassic and Late Jurassic stages

Streptospondylus is a genus of megalosaurid theropod dinosaur known from the Late Jurassic period of France, 161 million years ago. It was a medium-sized predator with an estimated length of 6 meters (19.5 ft) and a weight of 500 kg (1,100 lbs).

Under dispute

Streptospondylus altdorfensis, stabilized as a valid theropod by the lectotype designation of Allain (2001), is a fragmentary taxon recovered as Megalosauria incertae sedis by Carrano and colleagues (2012) — unresolved between Megalosauridae and Spinosauridae, and possibly a basal member of either. Benson (2010) recovered it more basally, as Tetanurae incertae sedis.

Diagnosis

Two hypapophyses on the anterior dorsal vertebrae
Anterior dorsal centra strongly opisthocoelous and flattened ventrally; posterior dorsal centra platycoelous
Centra of the middle and posterior dorsal vertebrae elongate
Osseous ridge overhanging the dorsomedial edge of the astragalar ascending process not extending laterally to the middle of the distal tibia
Broad depression at the base of the ascending process of the astragalus
Astragalus lacking a posteromedial process

Species

Streptospondylus altdorfensis Meyer, 1832

Type species

Named for Altdorf, a locality where associated teleosaurid remains had also been found.

Lectotype: MNHN 8605, MNHN 8606, MNHN 8607, MNHN 8608, MNHN 8609, MNHN 8787, MNHN 8788, MNHN 8789, MNHN 8793, MNHN 8794, MNHN 8907 , Muséum national d'Histoire naturelle
Material: A series of cervical, dorsal, sacral, and caudal vertebrae, plus the distal left pubis, distal right fibula and tibia, right astragalus, and right calcaneum.
Horizon: Marnes de Dives Formation, Callovian–Oxfordian, Middle Jurassic–Late Jurassic , 165.3–154.8 million years ago Covers every bed that may have yielded the type specimen.
Locality: Falaises des Vaches Noires, near Honfleur, Calvados, France Carrano and colleagues (2012) give the horizon as "Marnes de Dives; late Callovian–early Oxfordian", and Allain (2001) dates the material only to "the Callovo-Oxfordian of the Vaches Noires". The Marnes de Dives itself is Callovian: Lebrun and Courville (2013) note that "only the final 6-7 m (out of 20 m) of the Marnes de Dives are 'visible' at the Vaches-Noires", all upper Callovian, beneath the Marnes de Villers, which "represent all or part of the basal Oxfordian (Mariae Zone)". The Oxfordian in those two works most likely reflects uncertainty over which of the cliff's beds yielded the material, rather than an Oxfordian Marnes de Dives.

References

Cuvier, G. (1808). Sur les ossemens fossiles de crocodiles, et particulièrement sur ceux des environs du Havre et de Honfleur, avec des remarques sur les squelettes des sauriens de la Thuringe [On the fossil bones of crocodiles, and particularly those from the neighborhood of Le Havre and Honfleur, with remarks on the skeletons of the saurians of Thuringia]. Annales du Muséum d'Histoire Naturelle 12: 73-110.
In French. First scientific description of the theropod vertebrae, then interpreted as crocodilian material from the Normandy Jurassic.
cuvier1808a
Meyer, C. E. H. (1832). Palaeologica zur Geschichte der Erde. 560 pp. Verlag von Siegmund Schmerber.
In German. Erects Streptospondylus altdorfensis from Geoffroy Saint-Hilaire's (1825) Steneosaurus rostromajor; first binomial referring to a theropod.
meyer1832a
Owen, R. (1842). Report on British fossil reptiles, Part II. Report of the British Association for the Advancement of Science 11: 60-204.
Argues Meyer was incorrect in changing the original specific name and creates the combination Streptospondylus rostromajor for what Meyer had called Streptospondylus altdorfensis.
owen1842a
Walker, A. D. (1964). 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. doi:10.1098/rstb.1964.0009
Refers the entire theropod material from Cuvier's series to the new species Eustreptospondylus divesensis (later moved to Piveteausaurus by Taquet 1977).
walker1964a
Allain, R. (2001). Redescription de Streptospondylus altdorfensis, le dinosaure théropode de Cuvier, du Jurassique de Normandie [Redescription of Streptospondylus altdorfensis, Cuvier's theropod dinosaur from the Jurassic of Normandy]. Geodiversitas 23(3): 349-367.
In French. Designates the postcranial theropod material as the lectotype, confirming altdorfensis as the valid epithet and Streptospondylus as a theropod genus.
allain2001a
Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.
Source of the hip height estimate.
jones2026c
Carrano, M. T.; Benson, R. B. J.; Sampson, S. D. (2012). The phylogeny of Tetanurae (Dinosauria: Theropoda). Journal of Systematic Palaeontology 10(2): 211-300. Informa UK Limited. doi:10.1080/14772019.2011.630927
Recovered Streptospondylus as Megalosauria incertae sedis.
carrano2012a
Benson, R. B. J. (2010). A description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the relationships of Middle Jurassic theropods. Zoological Journal of the Linnean Society 158(4): 882-935. Oxford University Press (OUP). doi:10.1111/j.1096-3642.2009.00569.x
Recovered it more basally as Tetanurae incertae sedis, not confidently megalosauroid
benson2010c
Geoffroy Saint-Hilaire, É. (1825). Recherches sur l'organisation des gavials [Researches on the organization of gavials]. Mémoires du Muséum national d'Histoire naturelle 12: 97-155. geoffroysaint-hilaire1825a
Lebrun, P.; Courville, P. (2013). Le Jurassique des falaises des Vaches-Noires [The Jurassic of the Vaches-Noires cliffs]. Fossiles 16-33.
Shows that only the uppermost, upper Callovian Marnes de Dives crops out at the Vaches Noires, beneath the basal Oxfordian Marnes de Villers.
lebrun2013a