Temporal range: Early Jurassic–Present, 199–0 Ma
Possible Late Triassic record
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauria
Clade: Neotheropoda
Clade: Averostra
Paul, 2002

Averostra, or "bird snouts", is a clade that includes most theropod dinosaurs that have promaxillary fenestrae, an extra opening in the bone that makes up the upper jaw.


Averostra was named by Gregory S. Paul in 2002 as an apomorphy-based clade defined as all theropods with a promaxillary fenestra.[1] It was later re-defined by Ezcurra and Cuny in 2007 at a node-based clade containing Ceratosaurus nasicornis, Allosaurus fragilis, their common ancestor and all its descendants.[2]


  1. ^ Paul, 2002. Dinosaurs of the Air. The John Hopkins University Press, Baltimore and London. 460 pp.
  2. ^ Ezcurra and Cuny, 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.

Various dinosaurs This article is part of Project Dinosaur Taxonomy, a All Birds project that aims to write comprehensive articles on every order, family and other taxonomic rank related to dinosaurs.
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