page_title: Timeline of ceratosaur research
section_title: 1990s
hierarchical_section_title: Timeline of ceratosaur research / 20th century / 1990s
caption_attribution_description: Velocisaurus unicus life restoration. Based on figures of skeletal remains[1] and skeletal reconstructions of related genera.
context_page_description: This timeline of ceratosaur research is a chronological listing of events in the history of paleontology focused on the ceratosaurs, a group of relatively primitive, often horned, predatory theropod dinosaurs that became the apex predators of the southern hemisphere during the Late Cretaceous. The nature and taxonomic composition of the Ceratosauria has been controversial since the group was first distinguished in the late 19th century. In 1884 Othniel Charles Marsh described the new genus and species Ceratosaurus nasicornis from the Late Jurassic Morrison Formation of the western United States. He felt that it belonged in a new family that he called the Ceratosauridae. He created the new taxon Ceratosauria to include both the Ceratosauridae and the ostrich-like ornithomimids. The idea of the Ceratosauria was soon contested, however. Later that same decade both Lydekker and Marsh's hated rival Edward Drinker Cope argued that the taxon was invalid.
  The idea of the Ceratosauria would regain some support more than thirty years later when Gilmore argued in its favor in 1920.
context_section_description: 1990
  Rowe and Gauthier published a node-based definition of Ceratosauria.
  1991
  Jean Le Loeuff and Eric Buffetaut described the new genus and species Tarascosaurus salluvicus.
  Bonaparte described the new genus and species Velocisaurus unicus.
  Novas regarded the Ceratosauria as consisting of two sister groups, the Coelophysoidea and their sister group, the Neoceratosauria.
  1994
  Thomas Holtz named the Coelophysoidea, then thought to be ceratosaurs. He defined them as all theropods more closely related to Coelophysis than to Ceratosaurus. Holtz defined the Neoceratosauria as all theropods closer to Ceratosaurus than to Coelophysis. He also defined the ceratosaur subclade Abelisauroidea as all theropods closer to Carnotaurus sastrei than to Ceratosaurus nasicornis.
  1995
  Hugues Accarie and others described the new genus and species Genusaurus sisteronis.
  1996
  Bonaparte described the new genus and species Ligabueino andesi.
  Sankar Chatterjee and Dhiraj Kumar Rudra observed that abelisaur teeth had lower crowns than other carnivorous dinosaurs either within or outside of Ceratosauria.
  1998
  Coria and Leonardo Salgado described the new genus and species Ilokelesia aguagrandensis.
  Sereno redefined Ceratosauria as all neotheropods closer to Coelophysis bauri than to birds. However, this definition never received broad acceptance by the scientific community because the Rowe had already defined the group in 1989, and therefore had priority. He also split the Abelisauridae into two subfamilies; the Abelisaurinae (all abelisaurids more closely related to Abelisaurus than to Carnotaurus) and Carnotaurinae (all abelisaurids more closely related to Carnotaurus than to Abelisaurus).
  Sampson and others described a more complete specimen of Majungatholus atops. They performed an X-ray CT scan of the skull of Majungatholus atopus. They found that the dome on the animal's skull formed of its frontal bone was actually hollow. This suggests that this structure was purely for display rather than used in fights between Majungatholus.
caption: Artistic restoration of Velocisaurus unicus
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