Ceratosauria

Ceratosaurs are members of a group of theropod dinosaurs defined as all theropods sharing a more recent common ancestry with Ceratosaurus than with birds. There is presently no universally agreed upon listing of species or diagnostic characters of Ceratosauria, though they were less derived anatomically than the more diverse Tetanurae. According to the latest and most accepted theory, Ceratosauria includes the Late Jurassic to Late Cretaceous theropods Ceratosaurus, Elaphrosaurus, and Abelisaurus, found primarily (though not exclusively) in the Southern Hemisphere. Originally, Ceratosauria included the above dinosaurs plus the Late Triassic to Early Jurassic Coelophysoidea (Coelophysis, Dilophosaurus, etc.), implying a much earlier divergence of ceratosaurs from other theropods. However, most recent studies have shown that coelophysoids do not form a clade with other ceratosaurs, and should be excluded from this group. Those analysis also imply that the Ceratosauria is probably a sister clade to the Tetanurae and thus shares a common ancestor.

Taxonomy

 * Infraorder Ceratosauria
 * Chuandongocoelurus
 * Elaphrosaurus
 * ?Lukousaurus
 * Family Ceratosauridae
 * Ceratosaurus
 * Genyodectes
 * Superfamily Abelisauroidea
 * Genusaurus
 * Ozraptor
 * Spinostropheus
 * Tarascosaurus
 * Family Abelisauridae
 * Family Noasauridae