Open Paleo

Megalosauridae

Fitzinger, 1843 Type genus Megalosaurus

Its genera lived 170.9–143.1 million years ago Middle Jurassic–Late Jurassic
Middle Jurassic and Late Jurassic stages

Megalosauridae is a family of large-bodied carnivorous theropod dinosaurs, among the first major radiation of big predatory dinosaurs, appearing in the Middle Jurassic and persisting into the Late Jurassic. These relatively primitive basal tetanurans comprise Megalosaurinae and a second subfamily, called Afrovenatorinae by Carrano and colleagues (2012) and Eustreptospondylinae by Rauhut and colleagues (2016), who place Eustreptospondylus at its base; Benson (2010) instead recovers Eustreptospondylus as the sister taxon of all other megalosaurids once Magnosaurus is removed. Long recognized mainly from Europe on the strength of fossils from France and the United Kingdom, the group is now known from North America and Africa, and possibly Asia (Carrano and colleagues, 2012). Megalosauroids and allosauroids were the first theropods to regularly reach giant sizes, with members weighing more than a tonne (Carrano and colleagues, 2012). Afrovenator has a long, low skull with little ornamentation (Carrano and colleagues, 2012). Within the broader group Megalosauria, the family is closely allied to the spinosaurids.

Diagnosis

  1. Humeral deltopectoral crest extending at least 0.52 of the way down the humeral shaft
  2. Absence of a fibular anterolateral tubercle
  3. Absence of the quadrate foramen
  4. Paroccipital processes directed dorsolaterally to laterally
  5. Well-defined longitudinal groove for neurovascular foramina on the lateral surface of the dentary
  6. Ischial shaft curving anteroventrally, with the antitrochanter absent and the symphysis expanded as an apron

Clades within Megalosauridae

Genera placed directly in Megalosauridae

  • Eustreptospondylus Walker, 1964 Callovian (165.3–161.5 Ma)United Kingdomunder dispute
  • Poekilopleuron Eudes-Deslongchamps, 1837 Bathonian (168.2–165.3 Ma)Franceunder dispute

References

  1. Fitzinger, L. (1843). Systema Reptilium. Fasciculus Primus. Amblyglossae. 106 pp. Braumüller und Seidel.

    Listed the family as "Megalosauri", attributed to Meyer; Carrano and colleagues (2012) credit Megalosauridae to this work.

    fitzinger1843a
  2. 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

    Redescribed Megalosaurus, listed the synapomorphies of Megalosauridae, and, with Magnosaurus removed, recovered Eustreptospondylus as the sister taxon of all other megalosaurids.

    benson2010c
  3. 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

    Named Afrovenatorinae as a new megalosaurid subfamily.

    carrano2012a
  4. Rauhut, O. M.; Hübner, T.; Lanser, K. (2016). A new megalosaurid theropod dinosaur from the late Middle Jurassic (Callovian) of north-western Germany: Implications for theropod evolution and faunal turnover in the Jurassic. Palaeontologia Electronica 19(2): 26A. Coquina Press. doi:10.26879/654

    Described Wiehenvenator; recovered Eustreptospondylus at the base of the second megalosaurid subfamily, which it calls Eustreptospondylinae for priority over Afrovenatorinae.

    rauhut2016a