Editing Tyrannosaurus (section)

=== Social behavior ===
[[File:Tyrannosaurus Growth Series LACM.jpg|left|thumb|Mounted skeletons of different age groups (skeleton in lower left based on the juvenile formerly named ''Stygivenator''), [[Natural History Museum of Los Angeles County]]]]
[[Philip J. Currie]] suggested that Tyrannosaurus may have been [[pack hunter]]s, comparing ''T. rex'' to related species ''[[Tarbosaurus bataar]]'' and ''[[Albertosaurus sarcophagus]]'', citing fossil evidence that may indicate [[Sociality|gregarious]] (describing animals that travel in herds or packs) behavior.<ref name="discoverdinogangs">{{cite web|date=June 22, 2011|title=Dino Gangs|url=http://www.discoveryuk.com/the-loop/dino-gangs/|archive-url=https://web.archive.org/web/20120119125039/http://www.discoveryuk.com/the-loop/dino-gangs/|archive-date=January 19, 2012|access-date=January 19, 2012|website=Discovery Channel}}</ref> A find in [[South Dakota]] where three ''T. rex'' skeletons were in close proximity may suggest the formation of a pack.<ref name="tgraphpack">{{Cite news|last=Collins|first=N.|date=June 22, 2011|title=Tyrannosaurus Rex 'hunted in packs'|work=The Telegraph|url=https://www.telegraph.co.uk/news/science/dinosaurs/8589113/Tyrannosaurus-Rex-hunted-in-packs.html |archive-url=https://ghostarchive.org/archive/20220110/https://www.telegraph.co.uk/news/science/dinosaurs/8589113/Tyrannosaurus-Rex-hunted-in-packs.html |archive-date=January 10, 2022 |url-access=subscription |url-status=live|access-date=March 23, 2014}}{{cbignore}}</ref><ref name="djournal">{{Cite web|last=Wallis|first=P.|date=June 11, 2012|title=Op-Ed: T. Rex pack hunters? Scary, but likely to be true|url=http://digitaljournal.com/article/326451|access-date=December 23, 2015|website=Digitaljournal.com|archive-date=April 16, 2021|archive-url=https://web.archive.org/web/20210416141803/http://www.digitaljournal.com/article/326451|url-status=live}}</ref> Cooperative pack hunting may have been an effective strategy for subduing prey with advanced [[anti-predator adaptation]]s which pose potential lethality such as ''[[Triceratops]]'' and ''[[Ankylosaurus]]''.<ref name="discoverdinogangs" />

Currie's pack-hunting ''T. rex'' hypothesis has been criticized for not having been [[peer-review]]ed, but rather was discussed in a television interview and book called ''Dino Gangs''.<ref name="switek2011dinogangs">{{Cite web|last=Switek|first=B.|date=July 25, 2011|title=A bunch of bones doesn't make a gang of bloodthirsty tyrannosaurs|url=https://www.theguardian.com/science/blog/2011/jul/25/bunch-bones-gang-bloodthirsty-tyrannosaurs|access-date=June 21, 2015|website=The Guardian|archive-date=December 21, 2018|archive-url=https://web.archive.org/web/20181221011020/https://www.theguardian.com/science/blog/2011/jul/25/bunch-bones-gang-bloodthirsty-tyrannosaurs|url-status=live}}</ref> The Currie theory for pack hunting by ''T. rex'' is based mainly by analogy to a different species, ''Tarbosaurus bataar''. Evidence of gregariousness in ''T. bataar'' itself has not been peer-reviewed, and to Currie's own admission, can only be interpreted with reference to evidence in other closely related species. According to Currie gregariousness in ''Albertosaurus sarcophagus'' is supported by the discovery of 26 individuals with varied ages in the Dry Island bonebed. He ruled out the possibility of a predator trap due to the similar preservation state of individuals and the near absence of herbivores.<ref name="switek2011dinogangs" /><ref name="currie1998">{{cite journal|last=Currie|first=Philip J.|author-link=Philip J. Currie|year=1998|title=Possible evidence of gregarious behaviour in tyrannosaurids|url=http://www.mnhn.ul.pt/geologia/gaia/21.pdf|journal=Gaia|volume=15|pages=271–277|archive-url=https://web.archive.org/web/20090326062833/http://www.mnhn.ul.pt/geologia/gaia/21.pdf|archive-date=March 26, 2009|access-date=May 3, 2009}} (not printed until 2000)</ref>

Additional support of tyrannosaurid gregariousness can be found in fossilized [[trackway]]s from the Upper Cretaceous [[Wapiti Formation]] of northeastern [[British Columbia]], Canada, left by three tyrannosaurids traveling in the same direction.<ref name="TG-20140724">{{Cite web|last=Sample|first=I.|date=July 23, 2014|title=Researchers find first sign that tyrannosaurs hunted in packs|url=https://www.theguardian.com/science/2014/jul/23/tyrannosaurs-hunted-packs-tracks-canada|access-date=July 28, 2014|website=[[The Guardian]]|archive-date=December 15, 2018|archive-url=https://web.archive.org/web/20181215141823/https://www.theguardian.com/science/2014/jul/23/tyrannosaurs-hunted-packs-tracks-canada|url-status=live}}</ref><ref>{{Cite journal|last=McCrea|first=R. T.|year=2014|title=A 'Terror of Tyrannosaurs': The First Trackways of Tyrannosaurids and Evidence of Gregariousness and Pathology in Tyrannosauridae|journal=PLOS ONE|volume=9|issue=7|pages=e103613|bibcode=2014PLoSO...9j3613M|doi=10.1371/journal.pone.0103613|pmc=4108409|pmid=25054328|doi-access=free}}</ref> According to scientists assessing the Dino Gangs program, the evidence for pack hunting in ''Tarbosaurus'' and ''Albertosaurus'' is weak and based on group skeletal remains for which alternate explanations may apply (such as drought or a flood forcing dinosaurs to die together in one place).<ref name="switek2011dinogangs" /> Others researchers have speculated that instead of large theropod social groups, some of these finds represent behavior more akin to [[Komodo dragon]]-like mobbing of carcasses, even going as far as to say true pack-hunting behavior may not exist in any non-avian dinosaurs due to its rarity in modern predators.<ref name="roachbrinkman2007">{{cite journal|last=Roach|first=Brian T.|author2=Brinkman, Daniel T.|year=2007|title=A reevaluation of cooperative pack hunting and gregariousness in ''Deinonychus antirrhopus'' and other nonavian theropod dinosaurs|journal=Bulletin of the Peabody Museum of Natural History|volume=48|issue=1|pages=103–138|doi=10.3374/0079-032X(2007)48[103:AROCPH]2.0.CO;2|s2cid=84175628 }}</ref>

Evidence of intraspecific attack was found by Joseph Peterson and his colleagues in the juvenile ''Tyrannosaurus'' nicknamed [[Jane (dinosaur)|Jane]]. Peterson and his team found that Jane's skull showed healed puncture wounds on the upper jaw and snout which they believe came from another juvenile ''Tyrannosaurus''. Subsequent CT scans of Jane's skull would further confirm the team's hypothesis, showing that the puncture wounds came from a traumatic injury and that there was subsequent healing.<ref name="JaneFacebiting">{{Cite journal |last1=Peterson |first1=J. E. |last2=Henderson |first2=M. D. |last3=Sherer |first3=R. P. |last4=Vittore |first4=C. P. |s2cid=85602478 |date=2009 |title=Face Biting On A Juvenile Tyrannosaurid And Behavioral Implications |url=http://palaios.sepmonline.org/content/24/11/780  |journal=PALAIOS |volume=24 |issue=11 |pages=780–784 |bibcode=2009Palai..24..780P |doi=10.2110/palo.2009.p09-056r |archive-url=https://archive.today/20130811100341/http://palaios.sepmonline.org/content/24/11/780 |archive-date=August 11, 2013}}</ref> The team would also state that Jane's injuries were structurally different from the parasite-induced lesions found in Sue and that Jane's injuries were on its face whereas the parasite that infected Sue caused lesions to the lower jaw.<ref name="JaneFaceBiteWeb">{{Cite web |url=http://www.niu.edu/PubAffairs/RELEASES/2009/nov/testytrex.shtml |title=The terrible teens of ''T. rex'' NIU scientists: Young tyrannosaurs did serious battle against each other |last=Parisi |first=T. |date=November 2, 2009 |publisher=Northern Illinois University |archive-url=https://web.archive.org/web/20130814164927/http://www.niu.edu/PubAffairs/RELEASES/2009/nov/testytrex.shtml |archive-date=August 14, 2013 |access-date=August 10, 2013}}</ref> Pathologies of other ''Tyrannosaurus'' specimens have been suggested as evidence of conspecific attack, including "Wyrex" with a hole penetrating its jugual and severe trauma on its tail that shows signs of [[bone remodeling]] (not regrowth).<ref name="Trexpaleobiologychapter10">{{cite book|author=Rothschild, B.M.|chapter=Clawing Their Way to the Top: Tyrannosaurid Pathology and Lifestyle|title=Tyrannosaurid Paleobiology |year=2013 |publisher=Indiana University Press |isbn=978-0-253-00930-2 |editor-last=Parrish |editor-first=M. J. |editor-last2=Molnar |editor-first2=R. E. |editor-last3=Currie |editor-first3=P. J. |editor-last4=Koppelhus |editor-first4=E. B. |series=Life of the Past |location=Bloomington (Ind.) |pages=211–222 }}</ref><ref>{{cite journal|author1=Anné, J.|author2=Whitney, M.|author3=Brocklehurst, R.|author4=Donnelly, K.|author5=Rothschild, B.|year=2023|title=Unusual lesions seen in the caudals of the hadrosaur, ''Edmontosaurus annectens''|journal=The Anatomical Record|volume=306|issue=3|pages=594–606|doi=10.1002/ar.25078|pmid=36089756 }}</ref>