Timeline of ceratosaur research

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Skeletal mount of Ceratosaurus nasicornis Kelvingrove Art Gallery Ceratosaurus.jpg
Skeletal mount of Ceratosaurus nasicornis

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. [1] In 1884 Othniel Charles Marsh described the new genus and species Ceratosaurus nasicornis from the Late Jurassic Morrison Formation of the western United States. [2] 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. [3] 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. [3]


The idea of the Ceratosauria would regain some support more than thirty years later when Gilmore argued in its favor in 1920. Nevertheless, the validity of Ceratosauria was disputed throughout much of the 20th century by researchers like Romer, Lapparent, Lavocat, Colbert, and Charig. However, in 1986, more than a century after Marsh first coined the name, Jacques Gauthier revived the idea. Three years later, Rowe published a new definition of Ceratosauria, all taxa more closely related to Ceratosaurus than to birds, based on Gauthier's use of the term. This modern use of the term was thought to include the many theropods discovered since the 1880s known as coelophysoids. [3] Ceratosaurus itself had loose joints between bones in the skull whose interpretation has been controversial. Paleontologist Robert T. Bakker has interpreted this condition as an adaptation to swallow prey larger than it would otherwise be able to fit through its jaws. [4]

Since the 1980s, major developments in ceratosaur taxonomy have centered on the discovery of the Abelisauridae, a new family of large ceratosaurs that were among the dominant predators of the southern hemisphere during the Cretaceous. [5] One of the most notable of these was Carnotaurus , an unusual horned theropod with a short face. [4] More recent noteworthy non-abelisaur ceratosaur discoveries include the protruding-toothed noasaurid Masiakasaurus knopfleri , named after the lead guitarist from Dire Straits. [6]

19th century

Ceratosaurus nasicornis skeleton restoration by O.C. Marsh from 1896, depicted in an erroneous upright position CeratosaurusSkeleton.jpg
Ceratosaurus nasicornis skeleton restoration by O.C. Marsh from 1896, depicted in an erroneous upright position







20th century



Illustration of the type specimen of Genyodectes serus Genyodectes.jpg
Illustration of the type specimen of Genyodectes serus




Skeletal restoration of known elements of Elaphrosaurs Elaphrosaurus bambergi.jpg
Skeletal restoration of known elements of Elaphrosaurs



Type specimen of Sarcosaurus woodi Sarcosaurus woodi.jpg
Type specimen of Sarcosaurus woodi








Neotype specimen of M. crenatissimus (MNHN.MAJ 1), the right dentary of a subadult individual, Museum national d'histoire naturelle, Paris. Majungasaurus.jpg
Neotype specimen of M. crenatissimus (MNHN.MAJ 1), the right dentary of a subadult individual, Muséum national d'histoire naturelle, Paris.








The type specimen of "Majungatholus", a Majungasaurus snout bump originally mistaken for a pachycephalosaur skull dome Majungasaurus skull.jpg
The type specimen of " Majungatholus ", a Majungasaurus snout bump originally mistaken for a pachycephalosaur skull dome




Skull of Carnotaurus sastrei Carnotaurus sastrei 22.jpg
Skull of Carnotaurus sastrei




Femur of Tarascosaurus salluvicus Tarascosaurus salluvicus femur.JPG
Femur of Tarascosaurus salluvicus
Artistic restoration of Velocisaurus unicus Velocisaurus.jpg
Artistic restoration of Velocisaurus unicus







Restoration of Majungasaurus based on the complete specimen described in 1998. Majungasaurus BW.jpg
Restoration of Majungasaurus based on the complete specimen described in 1998.

21st century


Restored skull of Masiakosaurus knopfleri Masiakosaurus skull FMNH.jpg
Restored skull of Masiakosaurus knopfleri




Skeletal mount of Aucasaurus garridoi Aucasaurus.jpg
Skeletal mount of Aucasaurus garridoi




Artistic restoration of Limusaurus inextricabilis Limusaurus inextricabilis.jpg
Artistic restoration of Limusaurus inextricabilis





Artistic restoration of Eoabelisaurus Eoabelisaurus restoration.png
Artistic restoration of Eoabelisaurus




Artistic restoration of Arcovenator Arcovenator.jpg
Artistic restoration of Arcovenator








See also


  1. Tykoski and Rowe (2004); "Introduction", page 47. Also cf. "Systematics and Evolution", page 64.
  2. 1 2 Tykoski and Rowe (2004); "Table 3.1: Ceratosauria", pages 48–49.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Tykoski and Rowe (2004); "Systematics and Evolution", page 64.
  4. 1 2 3 4 5 Tykoski and Rowe (2004); "Paleobiology", page 69.
  5. Holtz (1999"South American Discoveries: Keys to Dinosaur Evolution", pages 48–49.
  6. Sampson (2009); For description and naming, see "Dramatis Dinosaurae", pages 36–37. For family membership, see "Drifting Continents and Globe-Trotting Dinosaurs" page 59.
  7. 1 2 3 4 5 6 7 8 9 10 11 12 Tykoski and Rowe (2004); "Table 3.1: Ceratosauria", page 50.
  8. Tykoski and Rowe (2004); "Table 3.1: Ceratosauria", page 48.
  9. 1 2 3 4 5 6 7 8 9 10 11 12 13 Tykoski and Rowe (2004); "Table 3.1: Ceratosauria", page 49.
  10. Tykoski and Rowe (2004); "Paleobiology", page 70.
  11. Kellner and Campos (2002); "Abstract", page 163.
  12. Wilson et al. (2003); "Abstract", page 1.
  13. Calvo, Rubilar-Rogers and Moreno (2004); "Abstract", page 555.
  14. Sereno, Wilson, and Conrad (2004); "Abstract", page 1325.
  15. Allain et al. (2007); "Abstract", page 610.
  16. Sereno and Brusatte (2008); "Abstract", page 15.
  17. Canale et al. (2008); "Abstract", page 409.
  18. Xu et al. (2009); "Abstract", page 940.
  19. Ezcurra, Agnolin, and Novas (2010); "Abstract", page 1.
  20. Novas et al. (2010); "Abstract", page 45.
  21. Pol and Rauhut (2012); "Abstract", page 3170.
  22. Farke and Sertich (2013); "Abstract", page 1.
  23. Tortosa et al. (2013); "Abstract", page 63.
  24. Sánchez-Hernández and Benton (2014); "Abstract", page 581.
  25. Dalman (2014); "Abstract", page 181.
  26. Fillippi et al. (2016); in passim.
  27. Nicholas R. Longrich; Xabier Pereda-Suberbiola; Nour-Eddine Jalil; Fatima Khaldoune; Essaid Jourani (2017). "An abelisaurid from the latest Cretaceous (late Maastrichtian) of Morocco, North Africa". Cretaceous Research. 76: 40–52. Bibcode:2017CrRes..76...40L. doi:10.1016/j.cretres.2017.03.021.
  28. Cristiano Dal Sasso; Simone Maganuco; Andrea Cau (2018). "The oldest ceratosaurian (Dinosauria: Theropoda), from the Lower Jurassic of Italy, sheds light on the evolution of the three-fingered hand of birds". PeerJ. 6: e5976. doi:10.7717/peerj.5976. PMC   6304160 . PMID   30588396.
  29. Rafael Delcourt; Fabiano Vidoi Iori (2018). "A new Abelisauridae (Dinosauria: Theropoda) from São José do Rio Preto Formation, Upper Cretaceous of Brazil and comments on the Bauru Group fauna". Historical Biology: An International Journal of Paleobiology. 32 (7): 1–8. doi:10.1080/08912963.2018.1546700. S2CID   92754354.
  30. Slimane Zitouni; Christian Laurent; Gareth Dyke; Nour-Eddine Jalil (2019). "An abelisaurid (Dinosauria: Theropoda) ilium from the Upper Cretaceous (Cenomanian) of the Kem Kem beds, Morocco". PLOS ONE. 14 (4): e0214055. Bibcode:2019PLoSO..1414055Z. doi: 10.1371/journal.pone.0214055 . PMC   6445567 . PMID   30939139.
  31. Langer, Max Cardoso; de Oliveira Martins, Neurides; Manzig, Paulo César; de Souza Ferreira, Gabriel; de Almeida Marsola, Júlio César; Fortes, Edison; Lima, Rosana; Sant’ana, Lucas Cesar Frediani; da Silva Vidal, Luciano; da Silva Lorençato, Rosangela Honório; Ezcurra, Martín Daniel Ezcurra (2019). "A new desert-dwelling dinosaur (Theropoda, Noasaurinae) from the Cretaceous of south Brazil". Scientific Reports. 9 (1): 9379. Bibcode:2019NatSR...9.9379L. doi:10.1038/s41598-019-45306-9. PMC   6594977 . PMID   31243312.
  32. Cerroni, M.A.; Motta, M.J.; Agnolín, F.L.; Aranciaga Rolando, A.M.; Brissón Egli, F.; Novas, F.E. (2020). "A new abelisaurid from the Huincul Formation (Cenomanian-Turonian; Upper Cretaceous) of Río Negro province, Argentina". Journal of South American Earth Sciences. 98: 102445. Bibcode:2020JSAES..9802445C. doi:10.1016/j.jsames.2019.102445. S2CID   213781725.

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<i>Ceratosaurus</i> Genus of theropod dinosaur from the Late Jurassic period

Ceratosaurus was a carnivorous theropod dinosaur that lived in the Late Jurassic period. The genus was first described in 1884 by American paleontologist Othniel Charles Marsh based on a nearly complete skeleton discovered in Garden Park, Colorado, in rocks belonging to the Morrison Formation. The type species is Ceratosaurus nasicornis.

<i>Carnotaurus</i> Abelisaurid theropod dinosaur from the Late Cretaceous period

Carnotaurus is a genus of theropod dinosaur that lived in South America during the Late Cretaceous period, probably sometime between 71 and 69 million years ago. The only species is Carnotaurus sastrei. Known from a single well-preserved skeleton, it is one of the best-understood theropods from the Southern Hemisphere. The skeleton, found in 1984, was uncovered in the Chubut Province of Argentina from rocks of the La Colonia Formation. Carnotaurus is a derived member of the Abelisauridae, a group of large theropods that occupied the large predatorial niche in the southern landmasses of Gondwana during the late Cretaceous. Within the Abelisauridae, the genus is often considered a member of the Brachyrostra, a clade of short-snouted forms restricted to South America.

<span class="mw-page-title-main">Ceratosauria</span> Extinct clade of dinosaurs

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. According to the majority of the latest research, 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.

<i>Abelisaurus</i> Extinct genus of dinosaurs

Abelisaurus is a genus of predatory abelisaurid theropod dinosaur alive during the Late Cretaceous Period (Campanian) of what is now South America. It was a bipedal carnivore that probably reached about 7.4 metres in length, although this is uncertain as it is known from only one partial skull.

<i>Rugops</i> Genus of dinosaur

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 and weight of 410 kilograms. 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.

<span class="mw-page-title-main">Abelisauridae</span> Extinct family of dinosaurs

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 and Arcovenator have been described in France. Abelisaurids first appear in the fossil record of the early middle Jurassic period, and at least three genera survived until the end of the Mesozoic era 66 million years ago.

<span class="mw-page-title-main">Abelisauroidea</span> Extinct clade of dinosaurs

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Ilokelesia is an extinct genus of abelisaurid theropod, preserved in the layers of the earliest Late Cretaceous of the Huincul Formation, Neuquén Group, located near Plaza Huincul, Neuquén Province, Argentina. The specimen, consisting of very fragmentary elements of the skull and the axial and appendicular skeleton, was described by Rodolfo Coria and Leonardo Salgado in late 1998.

<i>Quilmesaurus</i> Extinct genus of dinosaurs

Quilmesaurus is a genus of carnivorous abelisaurid theropod dinosaur from the Patagonian Upper Cretaceous of Argentina. It was a member of Abelisauridae, closely related to genera such as Carnotaurus. The only known remains of this genus are leg bones which share certain similarities to a variety of abelisaurids. However, these bones lack unique features, which may render Quilmesaurus a nomen vanum.

<i>Compsosuchus</i> Extinct genus of dinosaurs

Compsosuchus is an extinct genus of abelisauroid dinosaur. It lived during the Late Cretaceous in India.

<i>Majungasaurus</i> Abelisaurid theropod dinosaur from the Late Cretaceous period

Majungasaurus is a genus of abelisaurid theropod dinosaur that lived in Madagascar from 70 to 66 million years ago, at the end of the Cretaceous Period, making it one of the last known non-avian dinosaurs that went extinct during the Cretaceous–Paleogene extinction event. The genus contains a single species, Majungasaurus crenatissimus. This dinosaur is also called Majungatholus, a name which is considered a junior synonym of Majungasaurus.

<i>Ekrixinatosaurus</i> Extinct genus of reptiles

Ekrixinatosaurus is a genus of abelisaurid theropod which lived approximately 100 to 97 million years ago during the Late Cretaceous period. Its fossils have been found in Argentina. Only one species is currently recognized, Ekrixinatosaurus novasi, from which the specific name honors of Dr. Fernando Novas for his contributions to the study of abelisaurid theropods, while the genus name refers to the dynamiting of the holotype specimen. It was a large abelisaur, measuring between 6.5 and 8 m in length and weighing 800 kg (1,800 lb).

<i>Genyodectes</i> Extinct genus of dinosaurs

Genyodectes is a genus of ceratosaurian theropod dinosaur from the Lower Cretaceous (Aptian) of South America. The holotype material was collected from the Cerro Barcino Formation, Cañadón Grande, Departamento Paso de Indios in the Chubut Province of Argentina and consists of an incomplete snout, including the premaxillae, portions of both maxillas, the right and left dentary, many teeth, a fragment of the left splenial, and parts of the supradentaries. These elements are generally poorly preserved and some are in articulation. The premaxilla of Genyodectes possesses relatively large and protruding teeth, similar to those of Ceratosaurus. The specific name, serus, means "late". In 2016 it was estimated to be 6.25 meters in length and 790 kg in weight.

<span class="mw-page-title-main">Ceratosauridae</span> Extinct family of dinosaurs

Ceratosauridae is an extinct family of theropod dinosaurs belonging to the infraorder Ceratosauria. The family's type genus, Ceratosaurus, was first found in Jurassic rocks from North America. Ceratosauridae is made up of the genera Ceratosaurus, found in North America, Tanzania, and Portugal, and Genyodectes, from the Early Cretaceous of Argentina. Unnamed probable ceratosaurids are known from limited material in the Middle Jurassic of Madagascar, the Late Jurassic of Switzerland, the Late Jurassic of Tanzania, and the Late Jurassic or possibly Early Cretaceous of Uruguay.

<span class="mw-page-title-main">Noasauridae</span> Extinct family of dinosaurs

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.

<i>Berberosaurus</i> Extinct genus of dinosaurs

Berberosaurus is a genus of neotheropod dinosaur, possibly a ceratosaur, from the Toarcian-age "Toundoute Continental Series" found in the Central High Atlas of Toundoute, Ouarzazate, Morocco. The type species of the genus Berberosaurus is B. liassicus, in reference to the Lias epoch. Berberosaurus might be the oldest known ceratosaur, and is based on partial postcranial remains. This genus represents the oldest formally identified theropod from the North of Africa, as well one of the few from the region in the Early Jurassic.

<span class="mw-page-title-main">Carnotaurinae</span> Extinct subfamily of reptiles

Carnotaurinae is a subfamily of the theropod dinosaur family Abelisauridae. It includes the dinosaurs Aucasaurus, Carnotaurus. The group was first proposed by American paleontologist Paul Sereno in 1998, defined as a clade containing all abelisaurids more closely related to Carnotaurus than to Majungasaurus.

<i>Arcovenator</i> Extinct genus of dinosaurs

Arcovenator is an extinct genus of abelisaurid theropod dinosaurs hailing from the Late Cretaceous of France. The type and only described species is Arcovenator escotae.

<span class="mw-page-title-main">Majungasaurinae</span> Extinct subfamily of reptiles

Majungasaurinae is a subfamily of large carnivorous theropods from the Upper Cretaceous, found in Madagascar, India, and France. It is a subgroup within the theropod family Abelisauridae, a Gondwanan clade known for their thick and often horned skulls and vestigial arms. The two subfamilies of Abelisauridae are Carnotaurinae, best known from the South American Carnotaurus, and Majungasaurinae, consisting of Madagascar’s Majungasaurus and its closest relatives. Their ancestors emerged in the Middle Jurassic, and the clade lasted until the Upper Cretaceous.

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.