Open Paleo

Averostra

Paul, 2002

Its genera lived 201.4–66.0 million years ago Early Jurassic–Late Cretaceous

Averostra, meaning "bird snouts," is a clade of theropod dinosaurs within Neotheropoda that encompasses most theropods, uniting the two great branches Ceratosauria and Tetanurae. It represents the only lineage of theropods to survive beyond the Early Jurassic, and so includes nearly every theropod from the Middle Jurassic onward, from the horned ceratosaurs and abelisaurs to the megalosaurs, allosaurs, and the feathered coelurosaurs that ultimately gave rise to birds. Its members are among the most derived theropods, distinguished by the complete loss of the fifth metacarpal, a hand bone that other saurischians retained in reduced form. They also share a promaxillary or maxillary fenestra, an extra opening near the front of the upper jaw, together with fewer teeth in the maxilla, a tooth row set further back along the jaw, and a lacrimal fenestra.

Clades within Averostra

Genera placed directly in Averostra

  • Dandakosaurus Nomen dubium Yadagiri, 1982 Sinemurian–Pliensbachian (199.5–184.2 Ma)Indiaincertae sedis
  • Deltadromeus Sereno et al., 1996 Cenomanian (100.5–93.9 Ma)Moroccoincertae sedisunder dispute
  • Dornraptor Baron, 2024 Hettangian–Sinemurian (201.4–192.9 Ma)United Kingdom
  • Fosterovenator Dalman, 2014 Kimmeridgian–Tithonian (154.8–143.1 Ma)United Statesincertae sedisunder dispute

References

  1. Paul, G. S. (2002). Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds. 1-472. Johns Hopkins University Press, Baltimore.

    Coined Averostra (p. 25) as an apomorphy-based name for avepods with an accessory maxillary opening into a maxillary sinus, and their descendants, in the clade including Dromaeosauridae.

    paul2002a
  2. Ezcurra, M. D.; Cuny, G. (2007). The coelophysoid Lophostropheus airelensis, gen. nov.: a review of the systematics of "Liliensternus" airelensis from the Triassic-Jurassic outcrops of Normandy (France). Journal of Vertebrate Paleontology 27(1): 73-86. Informa UK Limited. doi:10.1671/0272-4634(2007)27[73:tclagn]2.0.co;2

    Defined Averostra as the node-based clade of Ceratosaurus nasicornis, Allosaurus fragilis and all descendants of their common ancestor, following Paul's original arrangement.

    ezcurra2007a