Editing Tyrannosaurus (section)

===Feeding strategies===
{{Main|Feeding behavior of Tyrannosaurus|l1=Feeding behavior of ''Tyrannosaurus''}}
[[File:Tyrannosaurus tooth marks.png|thumb|upright|''Tyrannosaurus'' tooth marks on bones of various herbivorous dinosaurs]]
[[File:Tyrannosaurus and Triceratops at Natural History Museum of Los Angeles County.jpg|thumb|A ''Tyrannosaurus'' mounted next to a ''[[Triceratops]]'' at the [[Los Angeles Natural History Museum]]]]
Most paleontologists accept that ''Tyrannosaurus'' was both an active [[predator]] and a [[scavenger]] like most large [[carnivores]].<ref name="nationalgeographic">{{cite magazine |url=https://www.nationalgeographic.com/science/phenomena/2013/07/16/time-to-slay-the-t-rex-scavenger-debate/ |title=Time to Slay the ''T. rex'' Scavenger "Debate" |date=July 16, 2013 |magazine=National Geographic |archive-url=https://web.archive.org/web/20180712030717/https://www.nationalgeographic.com/science/phenomena/2013/07/16/time-to-slay-the-t-rex-scavenger-debate/ |archive-date=July 12, 2018 }}</ref> By far the largest carnivore in its environment, ''T. rex'' was most likely an [[apex predator]], preying upon [[hadrosaur]]s, armored herbivores like [[ceratopsia]]ns and [[ankylosaur]]s, and possibly [[sauropod]]s.<ref>{{Cite journal |url=https://www.smithsonianmag.com/science-nature/when-tyrannosaurus-chomped-sauropods-67170161/ |title=When ''Tyrannosaurus'' Chomped Sauropods |last=Black |first=Riley |date=April 13, 2012 |publisher=Smithsonian Media |access-date=August 24, 2013 |journal=Smithsonian Magazine |volume=25 |page=469 |doi=10.1671/0272-4634(2005)025[0469:TRFTUC]2.0.CO;2 |s2cid=131583311 |archive-date=April 12, 2019 |archive-url=https://web.archive.org/web/20190412174912/https://www.smithsonianmag.com/science-nature/when-tyrannosaurus-chomped-sauropods-67170161/ |url-status=live }}</ref> Enamel δ<sup>44/42</sup>Ca values also suggest the possibility that ''T. rex'' occasionally fed on carcasses of marine reptiles and fish washed up on the shores of the Western Interior Seaway.<ref>{{Cite journal |last1=Martin |first1=Jeremy E. |last2=Hassler |first2=Auguste |last3=Montagnac |first3=Gilles |last4=Therrien |first4=François |last5=Balter |first5=Vincent |date=February 10, 2022 |title=The stability of dinosaur communities before the Cretaceous–Paleogene (K–Pg) boundary: A perspective from southern Alberta using calcium isotopes as a dietary proxy |url=https://pubs.geoscienceworld.org/gsa/gsabulletin/article/134/9-10/2548/611716/The-stability-of-dinosaur-communities-before-the |journal=[[Geological Society of America Bulletin]] |language=en |volume=134 |issue=9–10 |pages=2548–2560 |doi=10.1130/B36222.1 |bibcode=2022GSAB..134.2548M |issn=0016-7606 |access-date=November 18, 2024 |via=GeoScienceWorld|hdl=2164/20498 |hdl-access=free }}</ref> A study in 2012 by Karl Bates and Peter Falkingham found that ''Tyrannosaurus'' had the most powerful bite of any terrestrial animal that has ever lived, finding an adult ''Tyrannosaurus'' could have exerted 35,000 to 57,000 [[Newton (unit)|N]] (7,868 to 12,814 [[Pound (force)|lbf]]) of force in the back teeth.<ref>{{Cite web |url=https://www.smithsonianmag.com/science-nature/the-tyrannosaurus-rexs-dangerous-and-deadly-bite-37252918/ |title=The ''Tyrannosaurus rex''s Dangerous and Deadly Bite |last=Black |first=Riley |date=2012 |website=Smithsonian Magazine |publisher=Smithsonian Institution |access-date=December 20, 2019 |archive-date=May 13, 2014 |archive-url=https://web.archive.org/web/20140513065820/https://www.smithsonianmag.com/science-nature/the-tyrannosaurus-rexs-dangerous-and-deadly-bite-37252918/ |url-status=live }}</ref><ref name="BatesFalkingham2012">{{Cite journal |last1=Bates |first1=K. T. |last2=Falkingham |first2=P. L. |date=February 29, 2012 |title=Estimating maximum bite performance in ''Tyrannosaurus rex'' using multi-body dynamics |journal=Biology Letters |volume=8 |issue=4 |pages=660–664 |doi=10.1098/rsbl.2012.0056 |pmc=3391458 |pmid=22378742 }}</ref><ref>{{Cite book |title=Oxford Handbook of Applied Dental Sciences |last=Scully |first=C. |publisher=Oxford University Press |year=2002 |isbn=978-0-19-851096-3 |page=[https://archive.org/details/oxfordhandbookof00cris/page/156 156] |url=https://archive.org/details/oxfordhandbookof00cris |url-access=registration }}</ref> Even higher estimates were made by Mason B. Meers in 2003.<ref name="MM03" /> This allowed it to crush bones during repetitive biting and fully consume the carcasses of large dinosaurs.<ref name="gignac" /> Stephan Lautenschlager and colleagues calculated that ''Tyrannosaurus'' was capable of a maximum jaw gape of around 80 degrees, a necessary adaptation for a wide range of jaw angles to power the creature's strong bite.<ref>{{Cite journal |title=Estimating cranial musculoskeletal constraints in theropod dinosaurs |date=November 4, 2015 |journal=Royal Society Open Science |volume=2 |issue=11 |page=150495 |doi=10.1098/rsos.150495 |pmid=26716007 |pmc=4680622 |last1=Lautenschlager |first1=Stephan |bibcode=2015RSOS....250495L }}</ref><ref>{{Cite web |url=https://www.sciencedaily.com/releases/2015/11/151103213705.htm |title=The better to eat you with? How dinosaurs' jaws influenced diet |date=November 3, 2015 |website=Science Daily |archive-url=https://web.archive.org/web/20151104162130/https://www.sciencedaily.com/releases/2015/11/151103213705.htm |archive-date=November 4, 2015 |access-date=September 14, 2018}}</ref>

A debate exists, however, about whether ''Tyrannosaurus'' was primarily a [[predation|predator]] or a pure [[scavenger]]. The debate originated in a 1917 study by Lambe which argued that large theropods were pure scavengers because ''Gorgosaurus'' teeth showed hardly any wear.<ref name="Lambe1917Gorgosaurus">{{Cite journal |last=Lambe |first=L. B. |year=1917 |title=The Cretaceous theropodous dinosaur ''Gorgosaurus'' |journal=Memoirs of the Geological Survey of Canada |volume=100 |pages=1–84 |doi=10.4095/101672 |url=https://www.biodiversitylibrary.org/item/252624 |doi-access=free |archive-date=September 9, 2021 |access-date=August 11, 2021 |archive-url=https://web.archive.org/web/20210909121735/https://www.biodiversitylibrary.org/item/252624 |url-status=live }}</ref> This argument disregarded the fact that theropods replaced their teeth quite rapidly. Ever since the first discovery of ''Tyrannosaurus'' most scientists have speculated that it was a predator; like modern large predators it would readily scavenge or steal another predator's kill if it had the opportunity.<ref name="FarlowHoltz2002FossilRecordPredation">{{Cite book |title=The Fossil Record of Predation |last1=Farlow |first1=J. O. |last2=Holtz |publisher=T. R. Jr. |year=2002 |editor-last=Kowalewski |editor-first=M. |series=The Paleontological Society Papers |volume=8 |pages=251–266 |chapter=The fossil record of predation in dinosaurs |editor-last2=Kelley |editor-first2=P. H. |chapter-url=http://www.yale.edu/ypmip/predation/Chapter_09.pdf |archive-url=https://web.archive.org/web/20081031093048/http://www.yale.edu/ypmip/predation/Chapter_09.pdf |archive-date=October 31, 2008 }}</ref>

Paleontologist [[Jack Horner (paleontologist)|Jack Horner]] has been a major proponent of the view that ''Tyrannosaurus'' was not a predator at all but instead was exclusively a scavenger.<ref name="hornerlessem1993" /><ref name="Horner1994SteakKnives">{{Cite journal |last=Horner |first=J. R. |year=1994 |title=Steak knives, beady eyes, and tiny little arms (a portrait of ''Tyrannosaurus'' as a scavenger) |journal=The Paleontological Society Special Publication |volume=7 |pages=157–164|doi=10.1017/S2475262200009497 }}</ref><ref name="BBC2003TrexOnTrial">{{cite news |url=http://news.bbc.co.uk/1/hi/sci/tech/3112527.stm |title=Science/Nature: ''T. rex'' goes on trial |last=Amos |first=J. |date=July 31, 2003 |work=BBC News |access-date=December 23, 2015 |archive-date=March 13, 2012 |archive-url=https://web.archive.org/web/20120313130020/http://news.bbc.co.uk/1/hi/sci/tech/3112527.stm |url-status=live }}</ref> He has put forward arguments in the popular literature to support the pure scavenger hypothesis:

* Tyrannosaur arms are short when compared to other known predators. Horner argues that the arms were too short to make the necessary gripping force to hold on to prey.<ref name="BBC2003TrexOnTrial2">{{cite news|last=Amos|first=J.|date=July 31, 2003|title=Science/Nature: ''T. rex'' goes on trial|work=BBC News|url=http://news.bbc.co.uk/1/hi/sci/tech/3112527.stm|access-date=December 23, 2015|archive-date=March 13, 2012|archive-url=https://web.archive.org/web/20120313130020/http://news.bbc.co.uk/1/hi/sci/tech/3112527.stm|url-status=live}}</ref> Other paleontologists such as [[Thomas R. Holtz Jr.|Thomas Holtz Jr.]] argued that there are plenty of modern-day predators that do not use their forelimbs to hunt such as [[Wolf|wolves]], [[hyena]]s, and [[Secretarybird|secretary birds]] as well as other extinct animals thought to be predators that would not have used their forelimbs such as [[Phorusrhacidae|phorusrhacids]].<ref name="FarlowHoltz2002FossilRecordPredation2">{{Cite journal|last1=Farlow|first1=J. O.|last2=Holtz|first2=T.R.|year=2002|editor-last=Kowalewski|editor-first=M.|editor2-last=Kelley|editor2-first=P. H.|title=The Fossil Record of Predation in Dinosaurs|url=http://www.yale.edu/ypmip/predation/Chapter_09.pdf|journal=The Paleontological Society Papers|volume=8|pages=251–266|doi=10.1017/S108933260000111X|archive-url=https://web.archive.org/web/20081031093048/http://www.yale.edu/ypmip/predation/Chapter_09.pdf|archive-date=October 31, 2008}}</ref><ref name="Tyrantkingbook">{{cite book|last1=Holtz|first1=Thomas R.|title=Tyrannosaurus rex: The Tyrant King|publisher=Book Publishers|year=2008|isbn=978-0-253-35087-9|editor-last1=Larson|editor-first1=Peter|pages=371–394|chapter=Chapter 20: A critical re-appraisal of the obligate scavenging hypothesis for Tyrannosaurus rex and other tyrant dinosaurs|editor-last2=Carpenter|editor-first2=Kenneth|chapter-url=https://www.academia.edu/293223|archive-date=November 15, 2021|access-date=November 15, 2021|archive-url=https://web.archive.org/web/20211115021956/https://www.academia.edu/293223|url-status=live}}</ref>
* Tyrannosaurs had large [[olfactory bulb]]s and [[olfactory nerve]]s (relative to their brain size). These suggest a highly developed sense of smell which could sniff out carcasses over great distances, as modern [[vulture]]s do. Research on the olfactory bulbs of dinosaurs has shown that ''Tyrannosaurus'' had the most highly developed sense of smell of 21 sampled dinosaurs.<ref name="Calgary Herald" />
* Tyrannosaur teeth could crush bone, and therefore could extract as much food ([[bone marrow]]) as possible from carcass remnants, usually the least nutritious parts. Karen Chin and colleagues have found bone fragments in [[coprolite]]s (fossilized feces) that they attribute to tyrannosaurs, but point out that a tyrannosaur's teeth were not well adapted to systematically chewing bone like [[hyena]]s do to extract marrow.<ref name="ChinEtal1998KingSizeCoprolite">{{Cite journal |last1=Chin |first1=K. |last2=Tokaryk |first2=T. T. |last3=Erickson |first3=G. M. |last4=Calk |first4=L. C. |s2cid=4343329 |date=June 18, 1998 |title=A king-sized theropod coprolite |journal=Nature |volume=393 |issue=6686 |pages=680–682 |bibcode=1998Natur.393..680C |doi=10.1038/31461|url=https://zenodo.org/record/3943146 }} Summary at {{cite journal |last=Monastersky |first=R. |date=June 20, 1998 |title=Getting the scoop from the poop of ''T. rex'' |journal=Science News |doi=10.2307/4010364 |jstor=4010364 |volume=153 |issue=25 |page=391 |url=http://www.sciencenews.org/pages/sn_arc98/6_20_98/fob2.htm |archive-url=https://web.archive.org/web/20130511121022/http://www.sciencenews.org/pages/sn_arc98/6_20_98/fob2.htm |archive-date=May 11, 2013}}</ref>
* Since at least some of ''Tyrannosaurus''{{'}}s potential prey could move quickly, evidence that it walked instead of ran could indicate that it was a scavenger.<ref name="Horner1994SteakKnives" /> On the other hand, recent analyses suggest that ''Tyrannosaurus'', while slower than large modern terrestrial predators, may well have been fast enough to prey on large [[hadrosaurs]] and [[ceratopsians]].<ref name="HutchinsonGarcia2002TrexSlow" /><ref name="manningetal2008" />

Other evidence suggests hunting behavior in ''Tyrannosaurus''. The eye sockets of tyrannosaurs are positioned so that the eyes would point forward, giving them [[binocular vision]] slightly better than that of modern [[hawk]]s. It is not obvious why [[natural selection]] would have favored this long-term trend if tyrannosaurs had been pure scavengers, which would not have needed the advanced [[depth perception]] that [[stereoscopic vision]] provides.<ref name="Stevens2006Binocular" /><ref name="jaffe" /> In modern animals, binocular vision is found mainly in predators.

[[File:DMNS Edmontosaurus.png|thumb|left|The damage to the tail vertebrae of this ''Edmontosaurus annectens'' skeleton (on display at the Denver Museum of Nature and Science) indicates that it may have been bitten by a ''Tyrannosaurus'']]
A skeleton of the hadrosaurid ''[[Edmontosaurus]] annectens'' has been described from Montana with healed tyrannosaur-inflicted damage on its tail [[vertebra]]e. The fact that the damage seems to have healed suggests that the ''Edmontosaurus'' survived a tyrannosaur's attack on a living target, i.e. the tyrannosaur had attempted active predation.<ref name="carpenter1998">{{Cite journal |last=Carpenter |first=K. |author-link=Kenneth Carpenter |year=1998 |title=Evidence of predatory behavior by theropod dinosaurs |url=http://vertpaleo.org/publications/jvp/15-576-591.cfm |journal=Gaia |volume=15 |pages=135–144 |archive-url=https://web.archive.org/web/20071117132451/http://vertpaleo.org/publications/jvp/15-576-591.cfm <!--Added by H3llBot--> |archive-date=November 17, 2007 |access-date=December 5, 2007}}</ref> Despite the consensus that the tail bites were caused by ''Tyrannosaurus'', there has been some evidence to show that they might have been created by other factors. For example, a 2014 study suggested that the tail injuries might have been due to ''Edmontosaurus'' individuals stepping on each other,<ref>{{cite book|title=Hadrosaurs|chapter=Paleopathology in Late Cretaceous Hadrosauridae from Alberta, Canada |date=2015|pages=540–571|publisher=Indiana University Press|isbn=978-0-253-01390-3|editor1=Eberth, David A.|editor2=Evans, David C.}} [https://www.researchgate.net/publication/290310286_Paleopathology_in_Late_Cretaceous_Hadrosauridae_from_Alberta_Canada preprint] {{Webarchive|url=https://web.archive.org/web/20200703105409/https://www.researchgate.net/publication/290310286_Paleopathology_in_Late_Cretaceous_Hadrosauridae_from_Alberta_Canada |date=July 3, 2020 }}</ref> while another study in 2020 backs up the hypothesis that biomechanical stress is the cause for the tail injuries.<ref>{{cite journal |journal=PALAIOS |date=2020 |volume=35 |issue=4 |doi=10.2110/palo.2019.079 |url=https://pubs.geoscienceworld.org/sepm/palaios/article-abstract/35/4/201/584648/SKELETAL-TRAUMA-WITH-IMPLICATIONS-FOR-INTRATAIL?redirectedFrom=fulltext-- |title=Skeletal Trauma with Implications for Intratail Mobility in Edmontosaurus Annectens from a Monodominant Bonebed, Lance Formation (Maastrichtian), Wyoming USA |last1=Siviero |first1=ART V. |last2=Brand |first2=Leonard R. |last3=Cooper |first3=Allen M. |last4=Hayes |first4=William K. |last5=Rega |first5=Elizabeth |last6=Siviero |first6=Bethania C.T. |s2cid=218503493 |pages=201–214 |bibcode=2020Palai..35..201S |archive-date=July 4, 2020 |access-date=July 2, 2020 |archive-url=https://web.archive.org/web/20200704084853/https://pubs.geoscienceworld.org/sepm/palaios/article-abstract/35/4/201/584648/SKELETAL-TRAUMA-WITH-IMPLICATIONS-FOR-INTRATAIL?redirectedFrom=fulltext-- |url-status=live }}</ref> There is also evidence for an aggressive interaction between a ''[[Triceratops]]'' and a ''Tyrannosaurus'' in the form of partially healed tyrannosaur tooth marks on a ''Triceratops'' brow horn and [[squamosal]] (a bone of the [[neck frill]]); the bitten horn is also broken, with new bone growth after the break. It is not known what the exact nature of the interaction was, though: either animal could have been the aggressor.<ref name="JH08">{{Cite book |title=Tyrannosaurus rex, the Tyrant King (Life of the Past) |last1=Happ |first1=J. |last2=Carpenter |first2=K. |publisher=Indiana University Press |year=2008 |isbn=978-0-253-35087-9 |editor-last=Carpenter |editor-first=K. |location=Bloomington |pages=355–368 |chapter=An analysis of predator–prey behavior in a head-to-head encounter between ''Tyrannosaurus rex'' and ''Triceratops'' |editor-last2=Larson |editor-first2=P. E.}}</ref> Since the ''Triceratops'' wounds healed, it is most likely that the ''Triceratops'' survived the encounter and managed to overcome the ''Tyrannosaurus''. In a battle against a bull ''Triceratops'', the ''Triceratops'' would likely defend itself by inflicting fatal wounds to the ''Tyrannosaurus'' using its sharp horns.<ref>{{Cite book |title=The Horned Dinosaurs |year=1996 |url=https://archive.org/details/horneddinosaursn00dods |url-access=limited |last=Dodson |first=P. |publisher=Princeton University Press |page=[https://archive.org/details/horneddinosaursn00dods/page/n32 19]}}</ref> Studies of [[Sue (dinosaur)|Sue]] found a broken and healed [[fibula]] and tail vertebrae, scarred facial bones and a tooth from another ''Tyrannosaurus'' embedded in a neck vertebra, providing evidence for aggressive behavior.<ref name="TC98">{{Cite journal |last1=Tanke |first1=D. H. |last2=Currie |first2=P. J. |year=1998 |title=Head-biting behavior in theropod dinosaurs: paleopathological evidence |url=http://www.mnhn.ul.pt/geologia/gaia/12.pdf  |journal=Gaia |issue=15 |pages=167–184 |issn=0871-5424 |archive-url=https://web.archive.org/web/20080227134632/http://www.mnhn.ul.pt/geologia/gaia/12.pdf |archive-date=February 27, 2008 |author-link=Darren Tanke}}</ref> Studies on hadrosaur vertebrae from the Hell Creek Formation that were punctured by the teeth of what appears to be a late-stage juvenile ''Tyrannosaurus'' indicate that despite lacking the bone-crushing adaptations of the adults, young individuals were still capable of using the same bone-puncturing feeding technique as their adult counterparts.<ref name="Peterson">{{Cite journal |last1=Peterson |first1=J. E. |last2=Daus |first2=K. N. |date=March 4, 2019 |title=Feeding traces attributable to juvenile ''Tyrannosaurus rex'' offer insight into ontogenetic dietary trends |journal=PeerJ |volume=7 |page=e6573 |doi=10.7717/peerj.6573 |issn=2167-8359 |pmid=30863686|pmc=6404657 |doi-access=free }}</ref>

''Tyrannosaurus'' may have had infectious [[saliva]] used to kill its prey, as proposed by [[William Abler]] in 1992. Abler observed that the {{Dinogloss|serrations}} (tiny protuberances) on the cutting edges of the teeth are closely spaced, enclosing little chambers. These chambers might have trapped pieces of carcass with bacteria, giving ''Tyrannosaurus'' a deadly, infectious bite much like the [[Komodo dragon]] was thought to have.<ref name="abler1992">{{Cite journal |last=Abler |first=W. L. |date=1992 |title=The serrated teeth of tyrannosaurid dinosaurs, and biting structures in other animals |journal=Paleobiology |volume=18 |issue=2 |pages=161–183 |doi=10.1017/S0094837300013956|bibcode=1992Pbio...18..161A |s2cid=88238481 }}</ref><ref name="goldstein2013">{{Cite journal |last1=Goldstein |first1=E. J. C. |last2=Tyrrell |first2=K. L. |last3=Citron |first3=D. M. |last4=Cox |first4=C. R. |last5=Recchio |first5=I. M. |last6=Okimoto |first6=B. |last7=Bryja |first7=J. |last8=Fry |first8=B. G. |s2cid=9932073 |date=June 1, 2013 |title=Anaerobic and aerobic bacteriology of the saliva and gingiva from 16 captive Komodo dragons (''Varanus komodoensis''): new implications for the "bacteria as venom" model |journal=Journal of Zoo and Wildlife Medicine |volume=44 |issue=2 |pages=262–272 |doi=10.1638/2012-0022R.1 |pmid=23805543 |issn=1042-7260}}</ref> Jack Horner and Don Lessem, in a 1993 popular book, questioned Abler's hypothesis, arguing that ''Tyrannosaurus''{{'}}s tooth serrations as more like cubes in shape than the serrations on a Komodo monitor's teeth, which are rounded.<ref name="hornerlessem1993" />{{rp|214–215}}

''Tyrannosaurus'', and most other theropods, probably primarily processed carcasses with lateral shakes of the head, like crocodilians. The head was not as maneuverable as the skulls of [[allosauroidea|allosauroids]], due to flat joints of the neck vertebrae.<ref name="ESetal2013">{{Cite journal |last1=Snively |first1=E. |last2=Cotton |first2=J. R. |last3=Ridgely |first3=R. |last4=Witmer |first4=L. M. |year=2013 |title=Multibody dynamics model of head and neck function in ''Allosaurus'' (Dinosauria, Theropoda) |journal=Palaeontologia Electronica |volume=16 |issue=2 |doi=10.26879/338|doi-access=free |bibcode=2013PalEl..16..338S }}</ref>

====Cannibalism====
Evidence also strongly suggests that tyrannosaurs were at least occasionally cannibalistic. ''Tyrannosaurus'' itself has strong evidence pointing towards it having been cannibalistic in at least a scavenging capacity based on tooth marks on the foot bones, humerus, and metatarsals of one specimen.<ref name="HornerCurrie_et.al._2010_Trex_cannibalism">{{Cite journal |last1=Longrich |first1=N. R. |last2=Horner |first2=J. R. |last3=Erickson |first3=G. M. |last4=Currie |first4=P. J. |year=2010 |title=Cannibalism in ''Tyrannosaurus rex'' |journal=PLOS ONE |volume=5 |issue=10 |page=e13419 |doi=10.1371/journal.pone.0013419 |pmc=2955550 |pmid=20976177|bibcode=2010PLoSO...513419L |doi-access=free }}</ref> Fossils from the [[Fruitland Formation]], [[Kirtland Formation]] (both Campanian in age) and the Maastrichtian aged [[Ojo Alamo Formation]] suggest that cannibalism was present in various tyrannosaurid genera of the San Juan Basin. The evidence gathered from the specimens suggests opportunistic feeding behavior in tyrannosaurids that cannibalized members of their own species.<ref>{{Cite web|url=https://www.researchgate.net/publication/348002335|title=NEW EVIDENCE FOR CANNIBALISM IN TYRANNOSAURID DINOSAURS FROM THE UPPER CRETACEOUS (CAMPANIAN/MAASTRICHTIAN) SAN JUAN BASIN OF NEW MEXICO|website=ResearchGate|access-date=May 8, 2021|archive-date=November 10, 2021|archive-url=https://web.archive.org/web/20211110091047/https://www.researchgate.net/publication/348002335_NEW_EVIDENCE_FOR_CANNIBALISM_IN_TYRANNOSAURID_DINOSAURS_FROM_THE_UPPER_CRETACEOUS_CAMPANIANMAASTRICHTIAN_SAN_JUAN_BASIN_OF_NEW_MEXICO|url-status=live}}</ref> A study from Currie, Horner, Erickson and Longrich in 2010 has been put forward as evidence of cannibalism in the genus ''Tyrannosaurus''.<ref name=HornerCurrie_et.al._2010_Trex_cannibalism/> They studied some ''Tyrannosaurus'' specimens with tooth marks in the bones, attributable to the same genus. The tooth marks were identified in the [[humerus]], foot bones and [[metatarsal]]s, and this was seen as evidence for opportunistic scavenging, rather than wounds caused by intraspecific combat. In a fight, they proposed it would be difficult to reach down to bite in the feet of a rival, making it more likely that the bitemarks were made in a carcass. As the bitemarks were made in body parts with relatively scantly amounts of flesh, it is suggested that the ''Tyrannosaurus'' was feeding on a cadaver in which the more fleshy parts already had been consumed. They were also open to the possibility that other [[Tyrannosauridae|tyrannosaurids]] practiced cannibalism.<ref name=HornerCurrie_et.al._2010_Trex_cannibalism />