20th century was the disputation of its existence, performed by the likes of Romer, Lapparent, Lavocat, Colbert, and Charig amongst others. Ceratosauria's fortune changed in 1986 when Jacques Gauthier, in an attempt to clarify the evolution of birds, grouped the majority of theropods into either Ceratosauria or Tetanurae. In Ceratosauria, he placed the ceratosaurs and coelophysoids. Gauthier's paper brought Ceratosauria's use back in vogue, and by the early 1990s, Abelisauridae had also been included under Ceratosauria. The triumvirate model of ceratosaurs, coelophysoids, and abelisaurids would go unchallenged until the early 2000s. Beginning at the turn of the millennium, a large number of paleontologists began excluding coelophysoids from Ceratosauria. This view is now widely held thanks to several similarities between Ceratosauria and Tetanurae not found in coelophysoids. Current phylogeny Most paleontologists have postulated that Ceratosauria split off from other theropods in the Late Triassic or earliest Jurassic. Despite this, no ceratosaurs have been discovered prior to the Early Jurassic, and even in the Middle Jurassic, species are sparse. Many scientists, such as Carrano and Sampson, have postulated the lack of specimens is due to a poor fossil record, rather than an indictment on the abundance of ceratosaurs at the time. A similarly large gap of specimens exist in the lower Cretaceous, particularly for Abelisauridae. Several recent discoveries of possible ceratosaurs have begun reshaping the phylogeny of Ceratosauria by filling in some of these gaps. Specifically, this has allowed paleontologists to begin altering the sub-groups inside Ceratosauria, in an attempt to find their most basal members. Currently, most paleontologists agree that Ceratosauria divides into two sub groups, Ceratosauridae and Abelisauroidea, with some variance as to which taxa are placed into basal polytomy. Abelisauroidea is further divided into the Abelisauridae and Noasauridae, with Abelisauridae, including Carnotaurinae. Recently, Rauhut and Carrano have placed Elaphrosaurinae inside Noasauridae while simultaneously moving the previous noasaurs into Noasaurinae. Into their new Noasauridae, they have uniquely included Deltadromeus and Limusaurus. The oldest known ceratosaur currently described is Saltriovenator zanellai which is dated to the Early Sinemurian, 199-197 Ma. The origin of Ceratosauria could have been in Northern Pangea where Saltriovenator, its close relative Berberosaurus, and Carmelopodus footprints have been found. The following cladogram follows an analysis by Diego Pol and Oliver W. M. Rauhut, 2012. A different conclusion was reached in a 2017 paper on Limusaurus ontogeny. Unlike other analyses, Noasauridae was placed more basal than Ceratosaurus, with the