Carnotaurini

Last updated

Contents

Carnotaurini
Temporal range: 85–66  Ma
Carnotaurus, Chlupac Museum, Prague-2.jpg
Mounted cast of a Carnotaurus sastrei skeleton, Chlupáč Museum, Prague
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: Abelisauridae
Clade: Furileusauria
Tribe: Carnotaurini
Coria et al. 2002
Type species
Carnotaurus sastrei
Bonaparte, 1985
Genera

Carnotaurini is a tribe of the theropod dinosaur family Abelisauridae from the Late Cretaceous period of Patagonia. It includes the dinosaurs Carnotaurus sastrei ; the type species, Aucasaurus garridoi , and Abelisaurus comahuensis . This group was first proposed by paleontologists Rodolfo Coria, Luis Chiappe, and Lowell Dingus in 2002, being defined as a clade containing " Carnotaurus sastrei , Aucasaurus garridoi , their most recent common ancestor, and all of its descendants."

Description

Anatomical description and geological distribution

Carnotaurins were relatively lightly built but large theropods, ranging in size from 6.1–7.8 m (20–26 ft) [1] and 1400–2000 kg (1.6–2.3 short tons) in weight. [2] [3] They were located in South America. All three species have been found in various[ That's two, which is not enough for "various". ] formations in Argentina: the Anacleto Formation of the Rio Colorado Subgroup in the Neuquén Basin and possibly the Sir Fernandez field of the Allen Formation to the southeast. [4] [5] [6] They are considered the most derived abelisaurids, with traits like very short, narrow skulls and extremely reduced forearms, even more so than other abelisaurids. [5] [7]

Paleobiology

Studies of the skull anatomy of the nominal species, Carnotaurus sastrei , lead to debate over what type of prey these animals hunted. Studies by Mazzetta et al. in 1998, 2004, and 2009 suggest that the jaw structure in Carnotaurus was built for swift, rather than strong, bites, with adaptations for mandibular kinesis to assist in swallowing small prey items whole. [8] Surprisingly, it exhibits a form of paracraniokinesis in which the dentary bone articulates against the surangular bone, further jointing the lower jaw and hypothetically allowing this animal a wider array of hunting strategies. [9]

However, in 1998 and 2009, Robert Bakker and Francois Therrien and colleagues contested this finding, stating that Carnotaurus had the exact same skull adaptations (short snout, small teeth, and a fortified occiput) as the Jurassic theropod Allosaurus , which presumably preyed upon large animals by gradual jaw slashing. [10]

Locomotion

Carnotaurus tail cross section.png
Cross section through the tail of Carnotaurus, showing the enlarged caudofemoralis muscle and the V-shaped caudal ribs
Robustly modeled tail of Carnotaurus.png
3D reconstructions of the tail muscles, tail, and pelvic bones seen from the side and above

Mazzetta et al. 1998–1999 and Phil Currie et al. 2011 found Carnotaurus to be a swift-running predator with semicursorial adaptations such as femoral resistance against bending moments [11] and a hypertrophied caudofemoralis muscle, the primary locomotory muscle in theropods which was located in the tail and pulled the femur backwards. [12] This enlarged caudofemoralis, giving them a speed estimate of 48–56 km/h (30–35 mph), allowed carnotaurins to be one of the fastest-running large theropod groups yet known. [13] [12]

Systematics

Past

The tribe Carnotaurini was named in 2002 by Rodolfo Coria et al. in 2002 after their discovery of Aucasaurus garridoi . They phylogenetically defined it as the most inclusive clade containing Carnotaurus sastrei , Aucasaurus garridoi , their most recent common ancestor, and all of its descendants. [14] Their morphological definition of it is by several synapomorphies of the clade, with two ambiguous ones: "the presence of hyposphene–hypantrum articulations in the proximal and middle sections of the caudal series, and cranial processes in the epipophyses of the cervical vertebrae." They defined more ambiguous synapomorphies due to the homologous materials not yet found in all other abelisaurids being: "a very broad coracoid (coracoid maximum width three times the distance across the scapular glenoid area), a humerus with a large and hemispherical head, an extremely short ulna and radius (ulna to humerus ratio 1:3 or less), and frontal prominences (swells or horns) that are located laterally on the skull roof." [15] The relatively outdated cladogram that they found is as follows:

Avetheropoda

Later in 2009, the carnotaurine Skorpiovenator was described by Juan Canale, Carlos Scanferla, Federico Agnolin, and Fernando E. Novas, who performed another phylogenetic study supporting the monophyly of Carnotaurini: [16]

Present

According to the modern consensus, as of the cladogram published in the description of Tralkasaurus cuyi after Cerroni et al. 2020, the tribe also contains Abelisaurus comahuensis , which has been found to be the closest relative of Aucasaurus garridoi and has been united with it under the clade Abelisaurinae across multiple occasions. [17] [18]

Related Research Articles

<i>Carnotaurus</i> Genus of 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. 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>Indosuchus</i> Abelisaurid theropod dinosaur genus from the Late Cretaceous Period

Indosuchus is a genus of abelisaurid dinosaur from the Late Cretaceous Period, a theropod related to Abelisaurus. Like most theropods, Indosuchus was a bipedal carnivore. It was about 7 metres long, weighed about 1.2 tonnes, and had a crested skull, flattened on the top.

<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.

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

Aucasaurus is a genus of medium-sized abelisaurid theropod dinosaur from Argentina that lived during the Late Cretaceous of the Anacleto Formation. It was smaller than the related Carnotaurus, although more derived in some ways, such as its extremely reduced arms and almost total lack of fingers. The type skeleton is complete to the thirteenth caudal vertebra, and so is relatively well understood, and is the most complete abelisaurid yet described. However, the skull is damaged, causing some paleontologists to speculate that it was involved in a fight prior to death.

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

Abelisauroidea is a diverse superfamily of ceratosaurian dinosaurs, typically regarded as a Cretaceous group, though the earliest abelisaurid remains are known from the Middle Jurassic of Argentina and possibly Madagascar. Possible Abelisauridae remains were also discovered in Late Jurassic Tendaguru Beds in Tanzania.

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

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>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 dinosaur

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).

<span class="mw-page-title-main">Anacleto Formation</span> Geologic formation in Argentina

The Anacleto Formation is a geologic formation with outcrops in the Argentine Patagonian provinces of Mendoza, Río Negro, and Neuquén. It is the youngest formation within the Neuquén Group and belongs to the Río Colorado Subgroup. Formerly that subgroup was treated as a formation, and the Anacleto Formation was known as the Anacleto Member.

<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>Skorpiovenator</i> Extinct genus of dinosaurs

Skorpiovenator is a genus of abelisaurid theropod dinosaur from the Late Cretaceous Huincul Formation of Argentina. It is one of the most complete and informative abelisaurids yet known, described from a nearly complete and articulated skeleton.

<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.

<span class="mw-page-title-main">Luis M. Chiappe</span> Argentine paleontologist (born 1962)

Luis María Chiappe is an Argentine paleontologist born in Buenos Aires who is best known for his discovery of the first sauropod nesting sites in the badlands of Patagonia in 1997 and for his work on the origin and early evolution of Mesozoic birds. He is currently the Vice President of Research and Collections at the Natural History Museum of Los Angeles County and director of the museum's Dinosaur Institute. He was a postdoctoral researcher at the American Museum of Natural History, New York after immigrating from Argentina. Chiappe is currently the curator of the award winning Dinosaur Hall at the Natural History Museum of Los Angeles County, an adjunct professor at the University of Southern California, BBC advisor and author of scientific and popular books.

<span class="mw-page-title-main">Timeline of ceratosaur research</span>

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.

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.

Teratopodus is an ichnogenus of titanosaurian sauropod footprint. It includes a single species, T. malarguensis, known from prints found in the Late Cretaceous Anacleto Formation of Argentina. The Teratopodus tracks represent some of the best sauropod pes tracks currently known from South America.

References

  1. Grillo, O. N.; Delcourt, R. (2016). "Allometry and body length of abelisauroid theropods: Pycnonemosaurus nevesi is the new king". Cretaceous Research. 69: 71–89. doi:10.1016/j.cretres.2016.09.001.
  2. Grillo, O. N.; Delcourt, R. (2016). "Allometry and body length of abelisauroid theropods: Pycnonemosaurus nevesi is the new king". Cretaceous Research. 69: 71–89. doi:10.1016/j.cretres.2016.09.001.
  3. Mazzetta *, Gerardo V.; Christiansen †, Per; Fariña, Richard A. (June 2004). "Giants and Bizarres: Body Size of Some Southern South American Cretaceous Dinosaurs". Historical Biology. 16 (2–4): 71–83. CiteSeerX   10.1.1.694.1650 . doi:10.1080/08912960410001715132. ISSN   0891-2963. S2CID   56028251.
  4. Bonaparte, J.; Novas, E.E. (1985). "Abelisaurus comahuensis, n.g., n.sp., Carnosauria del Crétacico Tardio de Patagonia" [Abelisaurus comahuensis, n.g., n.sp., Carnosauria from the Late Cretaceous of Patagonia]. Ameghiniana. 21: 259–265 via ResearchGate.
  5. 1 2 Bonaparte, José F.; Novas, Fernando E.; Coria, Rodolfo A. (1990). "Carnotaurus sastrei Bonaparte, the horned, lightly built carnosaur from the Middle Cretaceous of Patagonia" (PDF). Contributions in Science. 416: 1–41. doi:10.5962/p.226819. S2CID   132580445. Archived from the original (PDF) on July 21, 2010.
  6. Benton, Michael J. (2012). Prehistoric Life. Edinburgh, Scotland: Dorling Kindersley. p. 320. ISBN   978-0-7566-9910-9.
  7. Coria, Rodolfo A.; Chiappe, Luis M.; Dingus, Lowell. "A NEW CLOSE RELATIVE OF CARNOTAURUS SASTREI BONAPARTE 1985(THEROPODA: ABELISAURIDAE) FROM THE LATE CRETACEOUS OF PATAGONIA". researchgate.net. Retrieved 2 November 2002.
  8. Mazzetta, Gerardo V.; Cisilino, Adrián P.; Blanco, R. Ernesto; Calvo, Néstor (2009). "Cranial mechanics and functional interpretation of the horned carnivorous dinosaur Carnotaurus sastrei". Journal of Vertebrate Paleontology. 29 (3): 822–830. doi:10.1671/039.029.0313. hdl: 11336/34937 . S2CID   84565615.
  9. Mazzetta, Gerardo V.; Fariña, Richard A.; Vizcaíno, Sergio F. (1998). "On the palaeobiology of the South American horned theropod Carnotaurus sastrei Bonaparte" (PDF). Gaia. 15: 185–192.
  10. Bakker, Robert T. (1998). "Brontosaur killers: Late Jurassic allosaurids as sabre-tooth cat analogues" (PDF). Gaia. 15: 145–158.
  11. Mazzetta, Gerardo V.; Farina, Richard A. (1999). "Estimacion de la capacidad atlética de Amargasaurus cazaui Salgado y Bonaparte, 1991, y Carnotaurus sastrei Bonaparte, 1985 (Saurischia, Sauropoda-Theropoda)". XIV Jornadas Argentinas de Paleontologia de Vertebrados, Ameghiniana (in Spanish). 36 (1): 105–106.
  12. 1 2 Persons, W.S.; Currie, P.J. (2011). Farke, Andrew Allen (ed.). "Dinosaur Speed Demon: The caudal musculature of Carnotaurus sastrei and implications for the evolution of South American abelisaurids". PLOS ONE. 6 (10): e25763. Bibcode:2011PLoSO...625763P. doi: 10.1371/journal.pone.0025763 . PMC   3197156 . PMID   22043292.
  13. "Predatory dinosaur was fearsomely fast". CBC News . October 21, 2011. Retrieved April 22, 2017.
  14. Coria, Rodolfo A.; Chiappe, Luis M.; Dingus, Lowell. "A NEW CLOSE RELATIVE OF CARNOTAURUS SASTREI BONAPARTE 1985 (THEROPODA: ABELISAURIDAE) FROM THE LATE CRETACEOUS OF PATAGONIA". researchgate.net. Retrieved 2 November 2002.
  15. Coria, Rodolfo A.; Chiappe, Luis M.; Dingus, Lowell. "A NEW CLOSE RELATIVE OF CARNOTAURUS SASTREI BONAPARTE 1985(THEROPODA: ABELISAURIDAE) FROM THE LATE CRETACEOUS OF PATAGONIA". researchgate.net. Retrieved 2 November 2002.
  16. Canale, J. I.; Scanferla, C. A.; Agnolin, F. L.; Novas, F. E. (2008). "New carnivorous dinosaur from the Late Cretaceous of NW Patagonia and the evolution of abelisaurid theropods" (PDF). Naturwissenschaften. 96 (3): 409–414. Bibcode:2009NW.....96..409C. doi:10.1007/s00114-008-0487-4. hdl: 11336/52024 . PMID   19057888. S2CID   23619863.
  17. Coria, Rodolfo A.; Chiappe, Luis M.; Dingus, Lowell (2002). "A new close relative of Carnotaurus sastrei Bonaparte 1985 (Theropoda: Abelisauridae) from the Late Cretaceous of Patagonia". Journal of Vertebrate Paleontology. 22 (2): 460–465. doi:10.1671/0272-4634(2002)022[0460:ANCROC]2.0.CO;2. S2CID   131148538 via ResearchGate.
  18. 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.