Ceratosaurs are members of the clade Ceratosauria, a group of dinosaurs defined as all theropods sharing a more recent common ancestor with Ceratosaurus than with birds. The oldest known ceratosaur, Saltriovenator, dates to the earliest part of the Jurassic, around 199 million years ago. Ceratosauria includes three major clades: Ceratosauridae, Noasauridae, and Abelisauridae, found primarily in the Southern Hemisphere. Originally, Ceratosauria included the above dinosaurs plus the Late Triassic to Early Jurassic Coelophysoidea and Dilophosauridae, implying a much earlier divergence of ceratosaurs from other theropods. However, most recent studies have shown that coelophysoids and dilophosaurids do not form a natural group with other ceratosaurs, and are excluded from this group.
Carnosauria is an extinct group of carnivorous theropod dinosaurs that lived during the Jurassic and Cretaceous periods.
Carcharodontosauridae is a group of carnivorous theropod dinosaurs. In 1931, Ernst Stromer named Carcharodontosauridae as a family, which, in modern paleontology, indicates a clade within Carnosauria. Carcharodontosaurids include some of the largest land predators ever known: Giganotosaurus, Mapusaurus, Carcharodontosaurus, and Tyrannotitan all rivaled Tyrannosaurus in size. Estimates give a maximum weight of 8–10 metric tons for the largest carcharodontosaurids, while the smallest carcharodontosaurids were estimated to have weighed at least 500 kilograms (1,100 lb).
Rugops is a monospecific genus of basal abelisaurid theropod dinosaur from Niger that lived during the Late Cretaceous period in what is now the Echkar Formation. The type and only species, Rugops primus, is known only from a partial skull. It was named and described in 2004 by Paul Sereno, Jeffery Wilson and Jack Conrad. Rugops has an estimated length of 4.4–5.3 metres (14–17 ft) and weight of 410 kilograms (900 lb). The top of its skull bears several pits which correlates with overlaying scale and the front of the snout would have had an armour-like dermis.
Abelisauridae is a family of ceratosaurian theropod dinosaurs. Abelisaurids thrived during the Cretaceous period, on the ancient southern supercontinent of Gondwana, and today their fossil remains are found on the modern continents of Africa and South America, as well as on the Indian subcontinent and the island of Madagascar. Isolated teeth were found in the Late Jurassic of Portugal, and the Late Cretaceous genera Tarascosaurus, Arcovenator and Caletodraco have been described in France. Abelisaurids possibly first appeared during the Jurassic period based on fossil records, and some genera survived until the end of the Mesozoic era, around 66 million years ago.
Bahariasaurus is an enigmatic genus of large theropod dinosaur. The genus is known to have included at least 1 species, Bahariasaurus ingens, which was found in North African rock layers dating to the Cenomanian and Turonian ages of the Late Cretaceous. The only fossils confidently assigned to Bahariasaurus were found in the Bahariya Formation of the Bahariya oasis in Egypt by Ernst Stromer but were destroyed during a World War II bombing raid with the same raid taking out the holotype of Spinosaurus and Aegyptosaurus among other animals found in the Bahariya Formation. While there have been more fossils assigned to the genus such as some from the Farak Formation of Niger, these remains are referred to with much less certainty. Bahariasaurus is, by most estimations, one of the largest theropods, approaching the height and length of other large bodied theropods such as Tyrannosaurus rex and the contemporaneous Carcharodontosaurus. The aforementioned estimations tend to put it at around 11–12.2 metres in length and 4-4.8 tonnes in overall weight.
Deltadromeus is a genus of theropod dinosaur from the Aoufous Formation of Morocco.
Megaraptor is a genus of large theropod dinosaur that lived in the ages of the Late Cretaceous. Its fossils have been discovered in the Patagonian Portezuelo Formation of Argentina, South America. Initially thought to have been a giant dromaeosaur-like coelurosaur, it was classified as a neovenatorid allosauroid in previous phylogenies, but more recent phylogeny and discoveries of related megaraptoran genera has placed it as either a basal tyrannosauroid or a basal coelurosaur with some studies still considering it a neovenatorid.
Spinostropheus is a genus of carnivorous neotheropod theropod dinosaur that lived in the Middle Jurassic period and has been found in the Tiouraren Formation, Niger. The type and only species is S. gautieri.
Noasauridae is an extinct family of theropod dinosaurs belonging to the group Ceratosauria. They were closely related to the short-armed abelisaurids, although most noasaurids had much more traditional body types generally similar to other theropods. Their heads, on the other hand, had unusual adaptations depending on the subfamily. 'Traditional' noasaurids, sometimes grouped in the subfamily Noasaurinae, had sharp teeth which splayed outwards from a downturned lower jaw.
Orkoraptor is a genus of medium-sized megaraptoran theropod dinosaur from the late Cretaceous Period of Argentina. It is known from incomplete fossil remains including parts of the skull, teeth, tail vertebrae, and a partial tibia. The specialized teeth resemble those of some maniraptoriform theropods, namely the deinonychosaurs and compsognathids. This and other anatomical features led the authors who described it to suggest that it was a maniraptoran coelurosaur. However, subsequent studies found it to be a megaraptoran. Found in the Cerro Fortaleza Formation of Southern Patagonia, it is one of the southernmost carnivorous dinosaurs known from South America.
Aerosteon is a genus of megaraptoran dinosaur from the Late Cretaceous period of Argentina. Its remains were discovered in 1996 in the Anacleto Formation, which is from the late Campanian. The type and only known species is A. riocoloradensis. Its specific name indicates that its remains were found 1 km north of the Río Colorado, in Mendoza Province, Argentina.
The Kem Kem Group is a geological group in the Kem Kem region of eastern Morocco, whose strata date back to the Cenomanian stage of the Late Cretaceous. Its strata are subdivided into two geological formations, with the lower Ifezouane Formation and the upper Aoufous Formation used for the strata on the eastern side of the Atlas Mountains (Tinghir), with the Gara Sbaa Formation and Douira Formation used in the southern Tafilalt region. It is exposed on an escarpment along the Algeria–Morocco border.
Megaraptora is a clade of carnivorous theropod dinosaurs with controversial relationships to other tetanuran theropods. Its derived members, the Megaraptoridae are noted for their large hand claws and powerfully-built forelimbs, which are usually reduced in size in other large theropods.
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.
Aoniraptor is a genus of possibly megaraptoran or bahariasaurid theropod dinosaur from the Late Cretaceous of Argentina.
Gualicho is a genus of theropod dinosaur. The type species is Gualicho shinyae. It lived in what is now northern Patagonia, on what was then a South American island continent split off from the supercontinent Gondwana. The fossils were found in the Huincul Formation, dating to the late Cenomanian-early Turonian age of the upper Cretaceous Period, around 91 million years ago.
Tralkasaurus is a genus of abelisaurid dinosaur from the Huincul Formation from Río Negro Province in Argentina. The type and only species is Tralkasaurus cuyi, named in 2020 by Mauricio Cerroni and colleagues based on an incomplete skeleton. A medium-sized abelisaurid, Tralkasaurus exhibits a conflicting blend of characteristics found among the early-diverging abelisauroids with others that characterize the highly specialized clade Brachyrostra, and thus its position within the clade is poorly-resolved.
