Open Paleo

Ceratosauria

Marsh, 1884 Type genus Ceratosaurus

Its genera lived 199.5–66.0 million years ago Early Jurassic–Late Cretaceous

Ceratosauria is a clade of theropod dinosaurs that ranged from the Early Jurassic through the end of the Cretaceous, reaching its greatest diversity on the southern landmasses of Gondwana. It is composed of three major groups: the Ceratosauridae, the Noasauridae, and the Abelisauridae, the last of which thrived across the southern continents until the mass extinction 66 million years ago. Earlier definitions also placed the coelophysoids and dilophosaurids within the group, but most recent work excludes them, treating ceratosaurs as a more restricted assemblage. Members are generally moderately large predators, ranging from small, lightly built noasaurs to the bulky Carnotaurus. The clade is distinguished by a robust, often heavily ornamented or tall skull and by a marked shortening of the forelimbs, features that grow more pronounced in later forms such as the abelisaurids, while basal members remain closer in build to other early theropods.

Diagnosis

  1. Camellate internal pneumatic structure of the presacral vertebrae
  2. Six sacral vertebrae, incorporating an additional dorsosacral
  3. Strongly pneumatic sacral neural spines with paired lateral fossae and foramina
  4. Very low deltopectoral crest on the humerus
  5. Continuous ridge on the lateral ilium linking the supra-acetabular crest to the brevis shelf
  6. Distal ischium expanded into a fused, anteroposteriorly elongate triangular foot
  7. Enlarged iliofibularis tubercle on the fibula
  8. Astragalar distal condyles rotated 10 to 30 degrees anteriorly
  9. Fusion of the pelvic elements and of the astragalus and calcaneum in mature individuals

Clades within Ceratosauria

Genera placed directly in Ceratosauria

  • Afromimus Sereno, 2017 Albian (113.2–100.5 Ma)Nigerincertae sedisunder dispute
  • Berberosaurus Allain et al., 2007 Pliensbachian–Toarcian (192.9–174.7 Ma)Morocco
  • Eoabelisaurus Pol & Rauhut, 2012 Aalenian–Bajocian (174.7–168.2 Ma)Argentinaincertae sedisunder dispute
  • Saltriovenator Dal Sasso et al., 2018 Sinemurian (199.5–192.9 Ma)Italy
  • Spinostropheus Sereno et al., 2004 Bathonian–Oxfordian (168.2–154.8 Ma)Nigerunder dispute

References

  1. Marsh, O. C. (1884). The classification and affinities of dinosaurian reptiles. Nature 31: 68-69.

    Established the sub-order Ceratosauria, misprinted as "Cerastosauria", for the family Ceratosauridae and its genus Ceratosaurus.

    marsh1884c
  2. Marsh, O. C. (1884). Principal characters of American Jurassic dinosaurs; Part VIII, The order Theropoda. American Journal of Science 27(160): 329-340. American Journal of Science. doi:10.2475/ajs.s3-27.160.329

    Named Ceratosaurus nasicornis and the family Ceratosauridae on a skeleton from the Atlantosaurus beds of the Upper Jurassic of Colorado.

    marsh1884a
  3. Carrano, M. T.; Sampson, S. D. (2008). The Phylogeny of Ceratosauria (Dinosauria: Theropoda). Journal of Systematic Palaeontology 6(2): 183-236. doi:10.1017/S1477201907002246

    Phylogenetic monograph rediagnosing Ceratosauria (Ceratosaurus plus Abelisauroidea) and the source of its diagnostic characters.

    carrano2008a
  4. Marsh, O. C. (1896). The dinosaurs of North America. Sixteenth Annual Report of the United States Geological Survey, 1894–1895 133-244.

    Printed the sub-order as Ceratosauria, correcting the 1884 misprint.

    marsh1896a
  5. Ezcurra, M. D.; Agnolín, F. L. (2012). An abelisauroid dinosaur from the Middle Jurassic of Laurasia and its implications on theropod palaeobiogeography and evolution. Proceedings of the Geologists' Association 123(3): 500-507. doi:10.1016/j.pgeola.2011.12.003

    Credited Ceratosauria to Marsh (1896), treating "Cerastosauria" as a typographic error that Marsh emended.

    ezcurra2012b