Temporal range: Jurassic–Cretaceous
Ceratosaurs are a group of theropod dinosaurs defined as all theropods sharing a more recent common ancestry with Ceratosaurus than with birds. Ceratosauria includes the Upper Jurassic to Upper Cretaceous theropods Ceratosaurus, Elaphrosaurus, and Abelisaurus, found mainly in the southern hemisphere.
The earlies known Ceratosaur is from the Middle Jurassic of Patagonia, Eoabelisaurus. It predates the so far oldest known secure member of this lineage by more than 40 million years. The almost complete skeleton reveals the earliest evolutionary stages of the distinctive features of abelisaurids, such as the modification of the forelimb.
Originally, Ceratosauria included the above dinosaurs plus the Upper Triassic to Lower Jurassic Coelophysis and Dilophosaurus. This implied a much earlier divergence of ceratosaurs from other theropods. However, recent studies have shown that coelophysoids and dilophosaurids do not form a natural group with other ceratosaurs, and so they are excluded from this group.
Distribution through time[change | change source]
References[change | change source]
- Pol, Diego & Rauhut, Oliver W.M. 2012. A Middle Jurassic abelisaurid from Patagonia and the early diversification of theropod dinosaurs. Proceedings of the Royal Society B: Biological Sciences.