{{pp-pc1}} {{short description|Extinct group of theropod dinosaurs}} {{Distinguish|Carnotaurus}} {{redirect|Carnosaur|the 1984 horror novel|Carnosaur (novel)|the 1993 film adaptation|Carnosaur (film)|the film series|Carnosaur (series)}} {{Automatic taxobox | name = Carnosaurs | fossil_range = <br/>Middle Jurassic – Late Cretaceous, {{Fossil range|earliest=Toarcian|174|90}} Possible Toarcian records. | image = Carnosauria (sensu stricto) Infobox Panoply.png | image_caption = Four carnosaurs (top to bottom): ''Sinraptor'', ''Acrocanthosaurus'', ''Concavenator'', ''Allosaurus'' | image_upright = 1.3 | taxon = Carnosauria | authority = von Huene, 1920 | subdivision_ranks = Subgroups | subdivision = *{{extinct}}''Altispinax''? *{{extinct}}''Gasosaurus''? *{{extinct}}''Monolophosaurus''? *{{extinct}}''Poekilopleuron''? *{{extinct}}'''Megalosauroidea'''? <small>(possibly paraphyletic)</small> *{{extinct}}'''Allosauroidea''' <small>Marsh, 1878</small> **{{extinct}}''Asfaltovenator'' **{{extinct}}''Eocarcharia''? **{{extinct}}''Erectopus'' **{{extinct}}''Lourinhanosaurus''? **{{extinct}}''Siamotyrannus''? **{{extinct}}''Xuanhanosaurus''? **{{extinct}}'''Allosauridae''' **{{extinct}}'''Metriacanthosauridae''' **{{extinct}}'''Piatnitzkysauridae'''? **{{extinct}}'''Carcharodontosauria''' <small>Benson, Carrano and Brusatte, 2010</small> ***{{extinct}}''Datanglong''? ***{{extinct}}''Concavenator''? ***{{extinct}}''Kelmayisaurus''? ***{{extinct}}''Lusovenator'' ***{{extinct}}''Neovenator'' ***{{extinct}}''Siamraptor'' ***{{extinct}}'''Carcharodontosauridae''' {{Collapse top|title=Uncertain or possible members |left=yes|padding=0|border=0|border2=0|bg=clear|bg2=clear}} *{{extinct}}''Aorun'' *{{extinct}}''Bahariasaurus'' *{{extinct}}''Chilantaisaurus'' *{{extinct}}''Compsognathus'' *{{extinct}}''Deltadromeus'' *{{extinct}}''Gualicho'' *{{extinct}}''Juravenator'' *{{extinct}}''Labocania'' *{{extinct}}''Nedcolbertia'' *{{extinct}}''Scipionyx'' *{{extinct}}''Sciurumimus'' *{{extinct}}''Siats'' *{{extinct}}''Wakinosaurus'' {{Collapse bottom}} | synonyms = '''Allosauroidea'''? <small>Marsh, 1878</small> }} '''Carnosauria''' is an extinct group of carnivorous theropod dinosaurs that lived during the Jurassic and Cretaceous periods.
While Carnosauria was historically considered largely synonymous with '''Allosauroidea''', some recent studies have revived Carnosauria as clade including both Allosauroidea and Megalosauroidea (which is sometimes recovered as paraphyletic with respect to Allosauroidea), and thus including the majority of non-coelurosaurian members of theropod clade Tetanurae.<ref name="Rauhut2019" /> Other researchers have found Allosauroidea and Megalosauroidea to be unrelated groups.<ref name=":10">Cau A. (2024). [https://www.researchgate.net/publication/379902868_A_Unified_Framework_for_Predatory_Dinosaur_Macroevolution A Unified Framework for Predatory Dinosaur Macroevolution]. Bollettino della Società Paleontologica Italiana, 63(1): 1-19.</ref>
Distinctive characteristics of carnosaurs include large eye sockets, a long narrow skull and modifications of the legs and pelvis such as the thigh (femur) being longer than the shin (tibia).<ref>{{cite web|url=https://ucmp.berkeley.edu/diapsids/saurischia/carnosauria.html|title=Tremble Before the Carnosauria!|website=University of California Museum of Paleontology|last=Hutchinson|first=John R.|date=7 November 2005|orig-date=Originally published 11 November 1995|editor-last=Smith|editor-first=Dave|access-date=5 March 2024}}</ref>
Carnosaurs first appeared in the Middle Jurassic around {{Ma|174}}, and the last definitive carnosaur family Carcharodontosauridae became extinct in the Turonian epoch of the Late Cretaceous around {{Ma|90}}. Some theropod remains, once suggested to be putative carcharodontosaurids from the Maastrichtian epoch (72–66 mya) in South America, were later reinterpreted as those of other theropod groups including the abelisaurids and maniraptorans.<ref name="2017brazicarch">{{cite journal | last1 = Delcourt | first1 = R. | last2 = Grillo | first2 = O.N. | title = Carcharodontosaurids remained extinct in the Campanian-Maastrichtian: Reassessment of a fragmentary maxilla from Presidente Prudente Formation, Brazil | journal = Cretaceous Research | volume = 84 | pages = 515–524 | date = 2017 | doi = 10.1016/j.cretres.2017.09.008 }}</ref><ref>{{Cite journal|author1=Rafael Delcourt |author2=Natan S. Brilhante |author3=Orlando N. Grillo |author4=Aline M. Ghilardi |author5=Bruno G. Augusta |author6=Fresia Ricardi-Branco |year=2020 |title=Carcharodontosauridae theropod tooth crowns from the Upper Cretaceous (Bauru Basin) of Brazil: A reassessment of isolated elements and its implications to palaeobiogeography of the group |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=556 |article-number=109870 |doi=10.1016/j.palaeo.2020.109870 |bibcode=2020PPP...55609870D |s2cid=224864035 }}</ref>
==History of study== Carnosauria has traditionally been used as a dumping ground for all large theropods. Even non-dinosaurs, such as the rauisuchian ''Teratosaurus'', were once considered carnosaurs. However, analysis in the 1980s and 1990s revealed that other than size, the group shared very few characteristics, making it polyphyletic. Most former carnosaurs (such as the megalosaurids, the spinosaurids, and the ceratosaurs) were reclassified as more primitive theropods. Others (such as the tyrannosaurids) that were more closely related to birds were placed in Coelurosauria. Modern cladistic analysis defines Carnosauria as those tetanurans sharing a more recent common ancestor with ''Allosaurus'' than with modern birds.<ref>{{cite web|url=http://www.miketaylor.org.uk/dino/faq/s-class/phyletic/index.html|title=What do terms like monophyletic, paraphyletic and polyphyletic mean?}}</ref>
== Anatomy == thumb|left|Size comparison of seven carnosaurs Carnosaurs share certain distinctive features, one of which is a triangular-shaped pubic boot.<ref name=holtz1998>{{Cite journal|last=Holtz|first=Thomas|date=December 1998|title=A New Phylogeny of the Carnivorous Dinosaurs|journal=Gaia|volume=15|pages=5–61|citeseerx=10.1.1.211.3044}}</ref> They also have 3 fingers per hand, with the second and third digit being approximately equal in length. The femur is larger than the tibia. Another defining feature of carnosaurs is that the chevron bases on their tails have anterior and posterior bone growth.<ref>Mateus, Octávio. (1997). Lourinhanosaurus antunesi, A New Upper Jurassic Allosauroid (Dinosauria: Theropoda) from Lourinhã, Portugal. Mémorias da Academia Ciêncas de Lisboa. 37.</ref> The largest carnosaurs can reach up to 10 meters in length. The length of the body from the tail to the hip is between 54% and 62% of the total body length, and the length of the body from the head to the hip is between 38% and 46% of the total body length.<ref name=batesetal2012>{{cite journal |last1=Bates |first1=Karl T. |last2=Benson |first2=Roger B. J. |last3=Falkingham |first3=Peter L. |title=A computational analysis of locomotor anatomy and body mass evolution in Allosauroidea (Dinosauria: Theropoda) |journal=Paleobiology |date=1 June 2012 |volume=38 |issue=3 |pages=486–507 |doi=10.1666/10004.1 |bibcode=2012Pbio...38..486B |s2cid=86326069 }}</ref> Carnosaurs scaled their limbs relative to their body in a way similar to how other large theropods, like the tyrannosaurids, did.<ref>{{cite journal |last1=Bybee |first1=Paul J. |last2=Lee |first2=Andrew H. |last3=Lamm |first3=Ellen-Thérèse |title=Sizing the Jurassic theropod dinosaur Allosaurus: Assessing growth strategy and evolution of ontogenetic scaling of limbs |journal=Journal of Morphology |year=2006 |volume=267 |issue=3 |pages=347–359 |doi=10.1002/jmor.10406 |pmid=16380967 |s2cid=35111050 }}</ref> During the Cretaceous, some carnosaurs grew to sizes similar to those of the largest tyrannosaurids.<ref name=":4" /> These large carnosaurs lived in the same time period as the other large theropods found in the upper Morrison and Tendaguru formations.<ref name=":3" />
Carnosaurs maintained a similar center of mass across all sizes, which is found to be between 37% and 58% of the femoral length anterior to the hip. Other similarities across all carnosaurs include the structure of their hind limb and pelvis. The pelvis in particular is thought to be designed to reduce stress regardless of body size. In particular, the way the femur is inclined reduces the bending and torsion stress. Furthermore, like other animals with tails, carnosaurs possess a caudofemoralis longus (CFL) muscle that allowed them to flex theirs. Larger carnosaurs are found to have a lower CFL muscle-to-body-mass proportion that smaller carnosaurs.<ref name=batesetal2012 />
In addition to body similarities, most carnosaurs, especially most allosauroids are also united by certain skull features. Some of the defining ones include a smaller mandibular fenestra, a short quadrate bone, and a short connection between the braincase and the palate.<ref>{{cite journal |last1=Sereno |first1=P. C. |last2=Dutheil |first2=D. B. |last3=Iarochene |first3=M. |last4=Larsson |first4=H. C. E. |last5=Lyon |first5=G. H. |last6=Magwene |first6=P. M. |last7=Sidor |first7=C. A. |last8=Varricchio |first8=D. J. |last9=Wilson |first9=J. A. |title=Predatory Dinosaurs from the Sahara and Late Cretaceous Faunal Differentiation |journal=Science |date=17 May 1996 |volume=272 |issue=5264 |pages=986–991 |doi=10.1126/science.272.5264.986 |pmid=8662584 |bibcode=1996Sci...272..986S |s2cid=39658297 |url=http://doc.rero.ch/record/13893/files/PAL_E831.pdf }}</ref> Allosauroid skulls are about 2.5 to 3 times longer as they are tall.<ref name=":3">{{cite journal |last1=Carrano |first1=Matthew T. |last2=Benson |first2=Roger B. J. |last3=Sampson |first3=Scott D. |title=The phylogeny of Tetanurae (Dinosauria: Theropoda) |journal=Journal of Systematic Palaeontology |year=2012 |volume=10 |issue=2 |pages=211–300 |doi=10.1080/14772019.2011.630927 |bibcode=2012JSPal..10..211C |s2cid=85354215 }}</ref> Their narrow skull along with their serrated teeth allow carnosaurs to better slice flesh off of their prey. Carnosaur teeth are flat and have equally-sized denticles on both edges. The flat side of the tooth face the sides of the skull, while the edges align on the same plane as the skull.<ref>{{cite journal |last1=Infante |first1=P. |last2=Canudo |first2=José Ignacio |last3=Ruiz Omeñaca |first3=José Ignacio |title=Primera evidencia de dinosaurios terópodos en la Formación Mirambel (Barremiense inferior, Cretácico Inferior) en Castellote, Teruel |trans-title=First evidence of theropod dinosaurs from the Mirambel Formation (Lower Barremian, Lower Cretaceous) from Castellote, Terue |language=es |journal=Geogaceta |date=2005 |volume=38 |hdl=10272/8751 |hdl-access=free }}</ref> From analyzing the skull of different carnosaurs, the volume of the cranial vault ranges between 95 milliliters in ''Sinraptor'' to 250 milliliters in ''Giganotosaurus''.<ref>Paulina-Carabajal, Ariana & Currie, Philip. (2012). New information on the braincase and endocast of Sinraptor dongi (Theropoda: Allosauroidea): Ethmoidal region, endocranial anatomy and pneumaticity. Vertebrata PalAsiatica. 50. 85-101.</ref>
''Allosaurus'' and ''Concavenator'' preserve skin impressions showing their integument. In ''Allosaurus,'' skin impressions showing small scales measuring 1 to 3 millimeters are known from the side of the torso and the mandible. Another skin impression from the ventral side of the neck preserves broad scutate scales. An impression from the base of the tail preserves larger scales around 2 centimeters in diameter. However, it has been noted that these may be sauropod scales due to their similarity and the fact that non-theropod remains were discovered associated with the tail of this particular ''Allosaurus'' specimen.<ref>{{Cite journal |last1=Hendrickx |first1=Christophe |last2=Bell |first2=Phil R. |last3=Pittman |first3=Michael |last4=Milner |first4=Andrew R. C. |last5=Cuesta |first5=Elena |last6=O'Connor |first6=Jingmai |last7=Loewen |first7=Mark |last8=Currie |first8=Philip J. |last9=Mateus |first9=Octávio |last10=Kaye |first10=Thomas G. |last11=Delcourt |first11=Rafael |date=June 2022 |title=Morphology and distribution of scales, dermal ossifications, and other non-feather integumentary structures in non-avialan theropod dinosaurs |url=https://onlinelibrary.wiley.com/doi/10.1111/brv.12829 |journal=Biological Reviews |language=en |volume=97 |issue=3 |pages=960–1004 |doi=10.1111/brv.12829 |pmid=34991180 |issn=1464-7931|url-access=subscription }}</ref> ''Concavenator'' preserves rectangular scutate scales on the underside of the tail, as well as scutate scales on top of the feet along with small scales on the rest of the feet. A series of knobs on the ulna of ''Concavenator'' have been interpreted by some authors as quill knobs theorized to have supported primitive quills;<ref>{{Cite journal |last1=Ortega |first1=Francisco |last2=Escaso |first2=Fernando |last3=Sanz |first3=José L. |date=September 2010 |title=A bizarre, humped Carcharodontosauria (Theropoda) from the Lower Cretaceous of Spain |url=https://www.nature.com/articles/nature09181 |journal=Nature |language=en |volume=467 |issue=7312 |pages=203–206 |doi=10.1038/nature09181 |pmid=20829793 |bibcode=2010Natur.467..203O |issn=1476-4687|url-access=subscription }}</ref> however this interpretation has been questioned, and they have been suggested to represent traces of ligaments instead.<ref>{{Citation |last1=Rauhut |first1=Oliver W. M. |title=The Origin of Birds: Current Consensus, Controversy, and the Occurrence of Feathers |date=2020 |work=The Evolution of Feathers: From Their Origin to the Present |pages=27–45 |editor-last=Foth |editor-first=Christian |series=Fascinating Life Sciences |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-27223-4_3 |isbn=978-3-030-27223-4 |last2=Foth |first2=Christian |editor2-last=Rauhut |editor2-first=Oliver W. M.}}</ref>
==Classification== Within Carnosauria, there is a slightly more exclusive clade, superfamily '''Allosauroidea'''. The clade Allosauroidea was originally named by Othniel Charles Marsh, but it was given a formal definition by Phil Currie and Zhao, and later used as a stem-based taxon by Paul Sereno in 1997.<ref name=curriezhao>{{cite journal | last1 = Currie | first1 = P. J. | last2 = Zhao | first2 = X. | year = 1993 | title = A new carnosaur (Dinosauria, Theropoda) from the Upper Jurassic of Xinjiang, People's Republic of China | journal = Canadian Journal of Earth Sciences | volume = 30 | issue = 10| pages = 2037–2081 | doi = 10.1139/e93-179 | bibcode = 1993CaJES..30.2037C | url = http://doc.rero.ch/record/14267/files/PAL_E1384.pdf }}</ref> Sereno was the first to provide a stem-based definition for the Allosauroidea in 1998, defining the clade as "All neotetanurans closer to ''Allosaurus'' than to Neornithes."<ref name=serenodefinition>{{cite journal | last1 = Sereno | first1 = P. C. | year = 1997 | title = The origin and evolution of dinosaurs | journal = Annual Review of Earth and Planetary Sciences | volume = 25 | pages = 435–489 | doi = 10.1146/annurev.earth.25.1.435 | bibcode = 1997AREPS..25..435S | url = http://doc.rero.ch/record/15399/files/PAL_E2750.pdf }}</ref> Kevin Padian used a node-based definition in his 2007 study which defined the Allosauroidea as ''Allosaurus'', ''Sinraptor'', their most recent common ancestor, and all of its descendants. Thomas R. Holtz and colleagues and Phil Currie and Ken Carpenter, among others, have followed this node-based definition.<ref name=thedinosauria>Holtz, T. R., Jr. and Osmólska H. 2004. Saurischia; pp. 21–24 in D. B. Weishampel, P. Dodson, and H. Osmólska (eds.), ''The Dinosauria'' (2nd ed.), University of California Press, Berkeley.</ref><ref>{{cite journal |last1=Currie |first1=Philip J. |last2=Carpenter |first2=Kenneth |date=2000 |title=A new specimen of ''Acrocanthosaurus atokensis'' (Theropoda, Dinosauria) from the Lower Cretaceous Antlers Formation (Lower Cretaceous, Aptian) of Oklahoma, USA |url=https://doc.rero.ch/record/15112/files/PAL_E2381.pdf |journal=Publications Scientifiques du Muséum national d'Histoire naturelle, Paris |volume=22 |issue=2 |pages=207–246}}</ref> Depending on the study, Carnosauria and Allosauroidea are sometimes considered synonymous. In such cases, several researchers have elected to use Allosauroidea over Carnosauria.<ref name=":3" /><ref name=bensonetal2010>{{cite journal | last1 = Benson | first1 = R.B.J. | last2 = Carrano | first2 = M.T | last3 = Brusatte | first3 = S.L. | year = 2010 | title = A new clade of archaic large-bodied predatory dinosaurs (Theropoda: Allosauroidea) that survived to the latest Mesozoic | journal = Naturwissenschaften | volume = 97 | issue = 1| pages = 71–78 | doi = 10.1007/s00114-009-0614-x | pmid=19826771 | bibcode=2010NW.....97...71B| s2cid = 22646156 }}</ref>
===Conventional phylogeny=== The following cladogram illustrates the phylogenetic position of Allosauroidea within Theropoda. It is a simplified version of the tree presented in a synthesis of the relationships of the major theropod groups based on various studies conducted in the 2010s. The ⊞ button can be clicked to expand the clade and display the interrelationships of the four major allosauroid groups.<ref name=theropodphylogeny2015>{{cite journal | last1 = Hendrickx | first1 = C. | last2 = Hartman | first2 = S.A. | last3 = Mateus | first3 = O. | year = 2015 | title = An overview of non-avian theropod discoveries and classification | journal = PalArch's Journal of Vertebrate Palaeontology | volume = 12 | issue = 1 | pages = 1–73 }}</ref> {{clade |style=line-height:75%; |label1=Neotheropoda |1={{clade |1=Coelophysoidea 80 px |2={{clade |1=Dilophosauridae 100 px |label2=Averostra |2={{clade |1=Ceratosauria 120px |label2=Tetanurae |2={{clade |1=Megalosauroidea 140px |label2=Avetheropoda |2={{clade |label1='''Allosauroidea''' |1={{clade hidden |id=1 |expand-text=120px |1=Metriacanthosauridae 120px |label2='''Allosauria''' |2={{clade |1=Allosauridae 120px |label2='''Carcharodontosauria''' |2={{clade |1=''Neovenator'' <div style="{{MirrorH}}">100px</div> |2=Carcharodontosauridae 140px }} }} }} |label3=Coelurosauria |3={{clade sequential |1=Tyrannosauroidea 140 px |2=Compsognathidae 70px |3=Ornithomimosauria 80px |4=Maniraptora 80 px }} }} }} }} }} }} }}
===Alternative hypotheses=== The composition of the clade Carnosauria has been controversial among scientists since at least 2010. Different clades have been recovered by different authors, and a scientific consensus has yet to emerge.
One such clade is '''Neovenatoridae''', a proposed clade of carcharodontosaurian carnosaurs uniting some primitive members of the group such as ''Neovenator'' with the Megaraptora, a group of theropods with controversial affinities. Other studies recover megaraptorans as basal coelurosaurs unrelated to carcharodontosaurs. Other theropods with uncertain affinities such as ''Gualicho'', ''Chilantaisaurus'' and ''Deltadromeus'' are also sometimes included.<ref name="murusraptor">{{Cite journal |last1=Coria |first1=Rodolfo A. |last2=Currie |first2=Philip J. |date=20 July 2016 |title=A New Megaraptoran Dinosaur (Dinosauria, Theropoda, Megaraptoridae) from the Late Cretaceous of Patagonia |journal=PLOS ONE |volume=11 |issue=7 |article-number=e0157973 |doi=10.1371/journal.pone.0157973 |issn=1932-6203| pmid=27439002 | pmc=4954680|bibcode=2016PLoSO..1157973C |doi-access=free }}</ref><ref>{{Cite journal |last1=Méndez |first1=Ariel H. |last2=Novas |first2=Fernando E. |last3=Iori |first3=Fabiano V. |date=May–June 2012 |title=Premier enregistrement de Megaraptora (Theropoda, Neovenatoridae) au Brésil |trans-title=First record of Megaraptora (Theropoda, Neovenatoridae) from Brazil |journal=Comptes Rendus Palevol |language=en |volume=11 |issue=4 |pages=251–256 |doi=10.1016/j.crpv.2011.12.007 |hdl=11336/19445 |hdl-access=free }}</ref>
Neovenatoridae, as formulated by these authors, contained ''Neovenator'', ''Chilantaisaurus'', and a newly named clade: Megaraptora. Megaraptora contained ''Megaraptor'', ''Fukuiraptor'', ''Orkoraptor'', ''Aerosteon'', and ''Australovenator''. These genera were allied with the other neovenatorids on the basis of several features spread out throughout the skeleton, particularly the large amount of pneumatization present. The pneumatic ilium of ''Aerosteon'' was particularly notable, as ''Neovenator'' was the only other taxon known to have that trait at the time. Neovenatorids were envisioned as the latest-surviving allosauroids, which were able to persist well into the Late Cretaceous due to their low profile and coelurosaur-like adaptations.<ref name=bensonetal2010 /> Later studies supported this hypothesis, such as Carrano, Benson & Sampson large study of tetanuran relationships in 2012,<ref>{{Cite journal |last1=Carrano |first1=Matthew T. |last2=Benson |first2=Roger B. J. |last3=Sampson |first3=Scott D. |date=1 June 2012 |title=The phylogeny of Tetanurae (Dinosauria: Theropoda) |journal=Journal of Systematic Palaeontology |volume=10 |issue=2 |pages=211–300 |doi=10.1080/14772019.2011.630927 |bibcode=2012JSPal..10..211C |s2cid=85354215 |issn=1477-2019}}</ref> and Zanno & Makovicky description of the newly discovered theropod ''Siats'' in 2013, which they placed within Megaraptora. ''Fukuiraptor'' and ''Australovenator'' were consistently found to be close relatives of each other; this was also the case for ''Aerosteon'' and ''Megaraptor''. ''Orkoraptor'' was a "wildcard" taxon difficult to place with certainty.<ref name=Siats>{{Cite journal | last1 = Zanno | first1 = L. E. | last2 = Makovicky | first2 = P. J. | doi = 10.1038/ncomms3827 | title = Neovenatorid theropods are apex predators in the Late Cretaceous of North America | journal = Nature Communications | volume = 4 | article-number = 2827 | year = 2013 | pmid = 24264527| bibcode = 2013NatCo...4.2827Z | doi-access = free }}</ref>
Phylogenetic studies conducted by Benson, Carrano and Brusatte (2010) and Carrano, Benson and Sampson (2012) recovered the group Megaraptora and a few other taxa as members of the Neovenatoridae. This would make neovenatorids the latest-surviving allosauroids; at least one megaraptoran, ''Orkoraptor'', lived near the end of the Mesozoic era, dating to the early Maastrichtian stage of the latest Cretaceous period, about 70 million years ago.<ref name=bensonetal2010 /><ref name=":3" />
The cladogram below follows a 2016 analysis by Sebastián Apesteguía, Nathan D. Smith, Rubén Juarez Valieri, and Peter J. Makovicky based on the dataset of Carrano ''et al.'' (2012).<ref name="Apesteguía2016">{{cite journal |author1=Sebastián Apesteguía |author2=Nathan D. Smith |author3=Rubén Juárez Valieri |author4=Peter J. Makovicky |year=2016 |title=An Unusual New Theropod with a Didactyl Manus from the Upper Cretaceous of Patagonia, Argentina |journal=PLOS ONE |volume=11 |issue=7 |article-number=e0157793 |doi=10.1371/journal.pone.0157793 |pmid=27410683 |pmc=4943716|bibcode=2016PLoSO..1157793A |doi-access=free }}</ref> {{clade| style=font-size:80%;line-height:85% |label1='''Allosauroidea''' |1={{clade |1=Metriacanthosauridae 120px |label2='''Allosauria''' |2={{clade |1=Allosauridae 120px |label2='''Carcharodontosauria''' |2={{clade |1=Carcharodontosauridae 140px |label2='''Neovenatoridae''' |2={{clade |1={{clade |1=''Deltadromeus'' |2=''Gualicho'' 80px}} |2={{clade |1=''Neovenator'' <div style="{{mirrorH}}">80px</div> |2={{clade |1=''Chilantaisaurus'' <div style="{{mirrorH}}">80px</div> |2=Megaraptora 60px }} }} }} }} }} }} }} Subsequent analyses have contradicted the above hypothesis. Novas and colleagues conducted an analysis in 2012 which found that ''Neovenator'' was closely related to carcharodontosaurids, simultaneously found ''Megaraptor'' and related genera to be coelurosaurs closely related to tyrannosaurids.<ref>{{cite journal |author1=F. E. Novas |author2=F. L. Agnolín |author3=M. D. Ezcurra |author4=J. I. Canale |author5=J. D. Porfiri | year= 2012 | title=Megaraptorans as members of an unexpected evolutionary radiation of tyrant-reptiles in Gondwana | url=http://www.ameghiniana.org.ar/index.php/ameghiniana/article/view/868/1618 | journal=Ameghiniana | volume=49 | issue=Suppl | pages=R33 }}</ref> However, Novas ''et al.'' subsequently found that megaraptorans lacked most of the key features in the hands of derived coelurosaurs including ''Guanlong'' and ''Deinonychus''. Instead, their hands retain a number of primitive characteristics seen in basal tetanurans such as ''Allosaurus''. Nevertheless, there are still a number of other traits that support megaraptorans as members of the Coelurosauria.<ref name=novasetal2016>{{cite journal | last1 = Novas | first1 = F.E. | last2 = Rolando | first2 = A.M.A. | last3 = Agnolin | first3 = F.L. | date = 2016 | url = https://museumvictoria.com.au/pages/381424/049-061_MMV74_Novas_4_WEB.pdf | title = Phylogenetic relationships of the Cretaceous Gondwanan theropods ''Megaraptor'' and ''Australovenator'': the evidence afforded by their manual anatomy. | journal = Memoirs of Museum Victoria | volume = 74 | pages = 49–61 | doi = 10.24199/j.mmv.2016.74.05 | archive-url = https://web.archive.org/web/20160818172356/https://museumvictoria.com.au/pages/381424/049-061_MMV74_Novas_4_WEB.pdf | archive-date = 2016-08-18 | hdl = 11336/48895 | hdl-access = free }}</ref><ref name=eotyrannus>{{cite journal |last1=Naish |first1=D. |last2=Cau |first2=A. |date=July 2022 |title=The osteology and affinities of ''Eotyrannus lengi'', a tyrannosauroid theropod from the Wealden Supergroup of southern England |journal=PeerJ |volume=10 |pages=e12727≠ |article-number=e12727 |doi=10.7717/peerj.12727|pmid=35821895 |pmc=9271276 |doi-access=free }}</ref> Other taxa like ''Deltadromeus'' and ''Gualicho'' have been alternatively recovered as coelurosaurs or noasaurid ceratosaurs.<ref name="Apesteguía2016" /> Over the recent years, a majority of researchers have increasingly classified megaraptorans as coelurosaurs.<ref name=":22">{{Cite journal |last1=Bell |first1=Phil R. |last2=Cau |first2=Andrea |last3=Fanti |first3=Federico |last4=Smith |first4=Elizabeth T. |date=August 2016 |title=A large-clawed theropod (Dinosauria: Tetanurae) from the Lower Cretaceous of Australia and the Gondwanan origin of megaraptorid theropods |journal=Gondwana Research |language=en |volume=36 |pages=473–487 |bibcode=2016GondR..36..473B |doi=10.1016/j.gr.2015.08.004}}</ref><ref name="Aoniraptor">{{Cite journal |last1=Motta |first1=Matías J. |last2=Aranciaga Rolando |first2=Alexis M. |last3=Rozadilla |first3=Sebastián |last4=Agnolín |first4=Federico E. |last5=Chimento |first5=Nicolás R. |last6=Egli |first6=Federico Brissón |last7=Novas |first7=Fernando E. |date=June 2016 |title=New theropod fauna from the Upper Cretaceous (Huincul Formation) of northwestern Patagonia, Argentina |url=https://www.researchgate.net/publication/304013683 |journal=New Mexico Museum of Natural History and Science Bulletin |volume=71 |pages=231–253 |via=ResearchGate}}</ref><ref name=":02">{{Cite journal |author1=Juan D. Porfiri |author2=Rubén D. Juárez Valieri |author3=Domenica D.D. Santos |author4=Matthew C. Lamanna |year=2018 |title=A new megaraptoran theropod dinosaur from the Upper Cretaceous Bajo de la Carpa Formation of northwestern Patagonia |journal=Cretaceous Research |volume=89 |pages=302–319 |doi=10.1016/j.cretres.2018.03.014 |bibcode=2018CrRes..89..302P |s2cid=134117648}}</ref><ref name=":42">{{Cite journal |last1=Rolando |first1=Alexis M. A. |last2=Motta |first2=Matias J. |last3=Agnolín |first3=Federico L. |last4=Manabe |first4=Makoto |last5=Tsuihiji |first5=Takanobu |last6=Novas |first6=Fernando E. |date=26 April 2022 |title=A large Megaraptoridae (Theropoda: Coelurosauria) from Upper Cretaceous (Maastrichtian) of Patagonia, Argentina |journal=Scientific Reports |volume=12 |issue=1 |article-number=6318 |doi=10.1038/s41598-022-09272-z |pmc=9042913 |pmid=35474310 |doi-access=free|bibcode=2022NatSR..12.6318A }}</ref>
Several recent analyses do not find a relationship between ''Neovenator'' and megaraptorans, which suggests that the latter were not carnosaurs or allosauroids. As a result of these findings, and the fact that ''Neovenator'' itself is the only uncontroversial neovenatorid, the family Neovenatoridae sees little use in recent publications.<ref name="sciencedirect.com">{{cite journal | doi = 10.1016/j.cretres.2013.04.001 | title=Evolution of the carnivorous dinosaurs during the Cretaceous: The evidence from Patagonia | journal=Cretaceous Research | date=2013 | volume=45 | pages=174–215 | first=Fernando E. | last=Novas| bibcode=2013CrRes..45..174N | hdl=11336/102037 | hdl-access=free }}</ref><ref name=eotyrannus />
In 2019, Rauhut and Pol described ''Asfaltovenator vialidadi'', a basal allosauroid displaying a mosaic of primitive and derived features seen within Tetanurae. Their phylogenetic analysis found traditional Megalosauroidea to represent a basal grade of carnosaurs, paraphyletic with respect to Allosauroidea. Because the authors amended the definition of Allosauroidea to include all theropods that are closer to ''Allosaurus fragilis'' than to either ''Megalosaurus bucklandii'' or Neornithes, the Piatnitzkysauridae was found to fall within Allosauroidea. A cladogram displaying the relationships they recovered is shown below.<ref name="Rauhut2019">{{cite journal |last1=Rauhut |first1=Oliver W. M. |last2=Pol |first2=Diego |title=Probable basal allosauroid from the early Middle Jurassic Cañadón Asfalto Formation of Argentina highlights phylogenetic uncertainty in tetanuran theropod dinosaurs |journal=Scientific Reports |date=11 December 2019 |volume=9 |issue=1 |page=18826 |doi=10.1038/s41598-019-53672-7 |pmid=31827108 |pmc=6906444 |bibcode=2019NatSR...918826R }}</ref> {{clade| style=font-size:80%;line-height:85% |label1='''Carnosauria''' |1={{clade |1=''Monolophosaurus'' |2={{clade |1=Spinosauridae 140px |2={{clade |1=Megalosauridae 120px |label2='''Allosauroidea''' |2={{clade |1=''Xuanhanosaurus'' |2={{clade |1=Piatnitzkysauridae 120px |2={{clade |1=''Asfaltovenator'' |2={{clade |1=Metriacanthosauridae 120px |2={{clade |1=Allosauridae 120px |2=Carcharodontosauria 140px}} }} }} }} }} }} }} }} }}
In 2025, photos of a destroyed specimen of ''Carcharodontosaurus'' were re-examined by Maximilian Kellermann and colleagues and were used to erect the new genus ''Tameryraptor''. A byproduct of this study was the recovery of a novel phylogenetic arrangement of carnosaurs. They did not recover megalosauroids as close relatives of allosauroids. Within Allosauroidea, their analyses, based on the dataset published by Wang and colleagues in 2017, consistently found Metriacanthosauridae and Carcharodontosauridae as sister taxa. They named this novel clade '''Carcharodontosauriformes''' and defined it as the least-inclusive clade containing both ''Carcharodontosaurus'' and ''Sinraptor''. A simplified version of one of the cladograms they published are shown below.<ref>{{cite journal |doi=10.1371/journal.pone.0311096|doi-access=free |title=Re-evaluation of the Bahariya Formation carcharodontosaurid (Dinosauria: Theropoda) and its implications for allosauroid phylogeny |date=2025 |last1=Kellermann |first1=Maximilian |last2=Cuesta |first2=Elena |last3=Rauhut |first3=Oliver W. M. |journal=PLOS ONE |volume=20 |issue=1 |article-number=e0311096 |pmid=39808629 |pmc=11731741 |bibcode=2025PLoSO..2011096K }}</ref> {{clade| style=font-size:80%; line-height:60% |label1='''Allosauroidea''' |1={{clade |1={{clade |1=''Allosaurus'' 120px |2=''Asfaltovenator'' }} |2={{clade |1={{clade |1=''Chilantaisaurus'' <div style="{{mirrorH}}">120px</div> |2=''Neovenator'' <div style="{{mirrorH}}">100px</div> }} |2={{clade |1=''Eocarcharia'' |label2='''Carcharodontosauriformes''' |2={{clade |1=Carcharodontosauridae 140px |2=Metriacanthosauridae 120px }} }} }} }} }}
== Paleobiology and behavior == Multiple severe injuries have been found on allosauroid remains, which implies that allosauroids were frequently in dangerous situations and supports the hypothesis of an active, predatory lifestyle. Despite the multitude of injuries, only a few of those injuries show signs of infection. For those injuries that did become infected, the infections were usually local to the site of the injury, implying that the allosauroid immune response was able to quickly stop any infection from spreading to the rest of the body. This type of immune response is similar to modern reptilian immune responses; reptiles secrete fibrin near infected areas and localize the infection before it can spread via the bloodstream.<ref name=":0">{{cite journal |last1=Foth |first1=Christian |last2=Evers |first2=Serjoscha W. |last3=Pabst |first3=Ben |last4=Mateus |first4=Octávio |last5=Flisch |first5=Alexander |last6=Patthey |first6=Mike |last7=Rauhut |first7=Oliver W.M. |title=New insights into the lifestyle of Allosaurus (Dinosauria: Theropoda) based on another specimen with multiple pathologies |journal=PeerJ |date=12 May 2015 |volume=3 |article-number=e940 |doi=10.7717/peerj.940 |pmid=26020001 |pmc=4435507 |doi-access=free }}</ref>
The injuries were also found to be mostly healed. This healing may indicate that allosauroids had an intermediate metabolic rate, similar to non-avian reptiles, which means they require fewer nutrients in order to survive. A lower nutrient requirement means allosauroids do not need to undertake frequent hunts, which lowers their risk of sustaining traumatic injuries.<ref name=":0" />
Although the remains of other large theropods like tyrannosaurids bear evidence of fighting within their species and with other predators, the remains of allosauroids do not bear much evidence of injuries from theropod combat. Most notably, despite a good fossil record, allosauroid skulls lack the distinctive face-biting wounds that are common in tyrannosaurid skulls, leaving open the question of if allosauroids engaged in interspecies and intraspecies fighting.<ref>{{cite journal |last1=Tanke |first1=Darren H. |last2=Currie |first2=Philip J. |title=Head-biting behavior in theropod dinosaurs: Paleopathological evidence |journal=Gaia |date=1998 |volume=15 |pages=167–184 |doi=10.7939/r34t6fj1p |doi-access=free }}</ref> Remains of the allosauroid ''Mapusaurus'' are also often found in groups, which could imply the existence of social behavior.<ref name="Canale-etal">{{Cite journal |last1=Canale |first1=Juan Ignacio |last2=Novas |first2=Fernando Emilio |last3=Salgado |first3=Leonardo |last4=Coria |first4=Rodolfo Aníbal |date=December 1, 2015 |title=Cranial ontogenetic variation in ''Mapusaurus roseae'' (Dinosauria: Theropoda) and the probable role of heterochrony in carcharodontosaurid evolution |journal=Paläontologische Zeitschrift |language=en |volume=89 |issue=4 |pages=983–993 |doi=10.1007/s12542-014-0251-3 |bibcode=2015PalZ...89..983C |s2cid=133485236 |issn=0031-0220|hdl=11336/19258 |hdl-access=free }}</ref> While there are alternative explanations for the groupings, like predator traps or habitat reduction due to drought, the frequency of finding allosauroid remains in groups supports the social animal theory. As social animals, allosauroids would share the burden of hunting, allowing injured members of the pack to recover faster.<ref name=":0" />
== Paleobiogeography == The paleobiogeographical history of allosauroids closely follows the order that Pangaea separated into the modern continents.<ref name=":6" /> By the Middle Jurassic period, tetanurans had spread to every continent and diverged into the allosauroids and the coelurosaurs.<ref name=":4" /> Allosauroids first appeared in the Middle Jurassic period and were the first giant taxa (weighing more than 2 tons) in theropod history. Along with members of the superfamily Megalosauroidea, the allosauroids were the apex predators that occupied the Middle Jurassic to the early Late Cretaceous periods.<ref name=":2">{{cite journal |last1=Benson |first1=Roger B. J. |last2=Carrano |first2=Matthew T. |last3=Brusatte |first3=Stephen L. |title=A new clade of archaic large-bodied predatory dinosaurs (Theropoda: Allosauroidea) that survived to the latest Mesozoic |journal=Naturwissenschaften |date=January 2010 |volume=97 |issue=1 |pages=71–78 |doi=10.1007/s00114-009-0614-x |pmid=19826771 |bibcode=2010NW.....97...71B |s2cid=22646156 }}</ref> Allosauroids have been found in North America, South America, Europe, Africa, and Asia.<ref name=":6">{{cite journal |last1=Brusatte |first1=Stephen L. |last2=Sereno |first2=Paul C. |title=Phylogeny of Allosauroidea (Dinosauria: Theropoda): Comparative analysis and resolution |journal=Journal of Systematic Palaeontology |date=1 January 2008 |volume=6 |issue=2 |pages=155–182 |doi=10.1017/S1477201907002404 |bibcode=2008JSPal...6..155B |s2cid=86314252 |url=https://www.research.ed.ac.uk/portal/en/publications/phylogeny-of-allosauroidea-dinosauria(5f3e6d44-fea6-468d-81d3-769f8c2830dd).html |hdl=20.500.11820/5f3e6d44-fea6-468d-81d3-769f8c2830dd |hdl-access=free }}</ref> A probable carcharodontosaurian specimen from the upper Strzelecki Group and the Eumeralla Formation (Aptian-Albian) of Australia might potentially extend their known distribution.<ref>{{cite journal|author1=Kotevski, J.|author2=Duncan, R.J.|author3=Ziegler, T.|author4=Bevitt, J.J.|author5=Vickers-Rich, P.|author6=Rich, T.H.|author7=Evans, A.R.|author8=Poropat, S.F.|year=2025|title=Evolutionary and paleobiogeographic implications of new carcharodontosaurian, megaraptorid, and unenlagiine theropod remains from the upper Lower Cretaceous of Victoria, southeast Australia|journal=Journal of Vertebrate Paleontology|volume=44|issue=4|at=e2441903|doi=10.1080/02724634.2024.2441903}}</ref>
Specifically, a world-wide dispersal of carcharodontosaurids likely happened in the Early Cretaceous. It has been hypothesized that the dispersal involved Italy's Apulia region (the "heel" of the Italian peninsula), which was connected to Africa by a land bridge during the Early Cretaceous period; various dinosaur footprints found in Apulia support this theory.<ref name=":5">{{cite journal |last1=Eddy |first1=Drew R. |last2=Clarke |first2=Julia A. |title=New Information on the Cranial Anatomy of ''Acrocanthosaurus atokensis'' and Its Implications for the Phylogeny of Allosauroidea (Dinosauria: Theropoda) |journal=PLOS ONE |date=21 March 2011 |volume=6 |issue=3 |article-number=e17932 |doi=10.1371/journal.pone.0017932 |pmid=21445312 |pmc=3061882 |bibcode=2011PLoSO...617932E |doi-access=free }}</ref> Allosauroids were present in both the northern and southern continents during the Jurassic and Early Cretaceous, but they were later replaced by the tyrannosauroids in North America and Asia during the Late Cretaceous. This is likely due to regional extinction events, which, along with increased species isolation through the severing of land connections between the continents, differentiated many dinosaurs in the Late Cretaceous.<ref name=":4">{{cite journal |last1=Sereno |first1=P. C. |title=The Evolution of Dinosaurs |journal=Science |date=25 June 1999 |volume=284 |issue=5423 |pages=2137–2147 |doi=10.1126/science.284.5423.2137 |pmid=10381873 }}</ref>
== See also == *Bone Wars *Cenomanian-Turonian boundary event *Theropod paleopathology
==References== {{Reflist}}
==External links== {{Wikispecies}} *{{commonscat-inline}}
{{Theropoda|A.}} {{Taxonbar|from=Q131190}}
Category:Carnosauria Category:Dinosaur clades