Editing Tyrannosaurus (section)

==History of research==
{{see also|Specimens of Tyrannosaurus|l1=Specimens of ''Tyrannosaurus''}}

===Earliest finds===
[[File:AMNH 3982 Manospondylus.jpg|alt=|left|thumb|[[Type (biology)|Type specimen]] (AMNH 3982) of ''Manospondylus gigas'']]
A tooth from what is now documented as a ''Tyrannosaurus rex'' was found in July 1874 upon [[South Table Mountain (Colorado)]] by [[Jarvis Hall (Colorado)]] student Peter T. Dotson under the auspices of Prof. [[Arthur Lakes]] near [[Golden, Colorado]].<ref>{{Cite news|title=The Colorado Transcript|date=July 8, 1874|via=www.coloradohistoricnewspapers.org}}</ref> In the early 1890s, [[John Bell Hatcher]] collected postcranial elements in eastern [[Wyoming]]. The fossils were believed to be from the large species ''[[Ornithomimus|Ornithomimus grandis]]'' (now ''[[Deinodon]]'') but are now considered ''T. rex'' remains.<ref name="quinlanetal2007" />

In 1892, [[Edward Drinker Cope]] found two vertebral fragments of a large dinosaur. Cope believed the fragments belonged to an "agathaumid" ([[Ceratopsidae|ceratopsid]]) dinosaur, and named them ''Manospondylus gigas'', meaning "giant porous vertebra", in reference to the numerous openings for blood vessels he found in the bone.<ref name="quinlanetal2007">{{Cite journal |last1=Breithaupt |first1=B. H. |last2=Southwell |first2=E. H. |last3=Matthews |first3=N. A. |date=October 15, 2005 |title=In Celebration of 100 years of ''Tyrannosaurus rex'': ''Manospondylus gigas'', ''Ornithomimus grandis'', and ''Dynamosaurus imperiosus'', the Earliest Discoveries of ''Tyrannosaurus rex'' in the West |url=http://gsa.confex.com/gsa/2005AM/finalprogram/abstract_96150.htm |journal=Abstracts with Programs; 2005 Salt Lake City Annual Meeting |publisher=[[Geological Society of America]] |volume=37 |issue=7 |page=406 |archive-url=https://archive.today/20120530024000/http://gsa.confex.com/gsa/2005AM/finalprogram/abstract_96150.htm |archive-date=May 30, 2012 |access-date=October 8, 2008|issn=0016-7592}}</ref> The ''M. gigas'' remains were, in 1907, identified by Hatcher as those of a theropod rather than a ceratopsid.<ref>{{Cite journal |last=Hatcher |first=J. B. |year=1907 |title=The Ceratopsia |url=https://archive.org/stream/TheCeratopsia/Musgs-1907-hatcherEtAl-theCeratopsiaLkUsaPart1Monograph#page/n111 |journal=Monographs of the United States Geological Survey |volume=49 |pages=113–114|issn=0886-7550}}</ref>

[[Henry Fairfield Osborn]] recognized the similarity between ''Manospondylus gigas'' and ''T. rex'' as early as 1917, by which time the second vertebra had been lost. Owing to the fragmentary nature of the ''Manospondylus'' vertebrae, Osborn did not synonymize the two genera, instead considering the older genus indeterminate.<ref name="osborn1917">{{Cite journal |last=Osborn |first=H. F. |author-link=Henry Fairfield Osborn |year=1917 |title=Skeletal adaptations of ''Ornitholestes'', ''Struthiomimus'', ''Tyrannosaurus'' |journal=Bulletin of the American Museum of Natural History |volume=35 |issue=43 |pages=733–771 |hdl=2246/1334}}</ref> In June 2000, the [[Black Hills Institute]] found around 10% of a ''Tyrannosaurus'' skeleton ([[Black Hills Institute|BHI]] 6248) at a site that might have been the original ''M. gigas'' locality.<ref name="larson2008">{{Cite book |title=''Tyrannosaurus rex'', The Tyrant King |url=https://archive.org/details/tyrannosaurusrex00plar |url-access=limited |last=Larson |first=N. L. |publisher=Indiana University Press |year=2008 |isbn=978-0-253-35087-9 |editor-last=Larson |editor-first=P. |location=Bloomington, IN |pages=[https://archive.org/details/tyrannosaurusrex00plar/page/n16 1]–55 |chapter=One hundred years of ''Tyrannosaurus rex'': the skeletons |editor-last2=Carpenter |editor-first2=K.}}</ref>

===Skeleton discovery and naming===
[[File:Tyrannosaurus skeleton.jpg|thumb|Outdated skeletal restoration by [[William Diller Matthew|William D. Matthew]] from 1905, published alongside Osborn's description paper]]
[[Barnum Brown]], assistant curator of the [[American Museum of Natural History]], found the first partial skeleton of ''T. rex'' in eastern Wyoming in 1900. Brown found another partial skeleton in the [[Hell Creek Formation]] in Montana in 1902, comprising approximately 34 fossilized bones.<ref name="osborn1905" /> Writing at the time Brown said "Quarry No. 1 contains the femur, pubes, humerus, three vertebrae and two undetermined bones of a large Carnivorous Dinosaur not described by [[Othniel Charles Marsh|Marsh]].&nbsp;... I have never seen anything like it from the [[Cretaceous]]."<ref name="dingus2010" /> [[Henry Fairfield Osborn]], president of the [[American Museum of Natural History]], named the second skeleton ''T. rex'' in 1905. The generic name is derived from the [[Greek language|Greek]] words {{lang|grc|τύραννος}} ({{translit|grc|tyrannos}}, meaning "tyrant") and {{lang|grc|[[wikt:σαῦρος|σαῦρος]]}} ({{translit|grc|sauros}}, meaning "lizard"). Osborn used the [[Latin language|Latin]] word {{lang|la|rex}}, meaning "king", for the specific name. The full [[Binomial nomenclature|binomial]] therefore translates to "tyrant lizard the king" or "King Tyrant Lizard", emphasizing the animal's size and presumed dominance over other species of the time.<ref name="osborn1905" />

[[File:Dynamosaurus holotype.jpg|thumb|left|''Dynamosaurus imperiosus'' [[holotype]] (NHMUK PV R8020, previously AMNH 5886) on display at the [[Natural History Museum, London|Natural History Museum]]]]
Osborn named the other specimen ''Dynamosaurus imperiosus'' in a paper in 1905.<ref name="osborn1905" /> In 1906, Osborn recognized that the two skeletons were from the same species and selected ''Tyrannosaurus'' as the preferred name.<ref name="osborn1906" /> In 1941, the ''T. rex'' type specimen was sold to the [[Carnegie Museum of Natural History]] in Pittsburgh, Pennsylvania, for $7,000.<ref name="dingus2010">{{Cite book |title=Barnum Brown: The Man Who Discovered ''Tyrannosaurus rex'' |url=https://archive.org/details/barnumbrownmanwh00ding |url-access=limited |last1=Dingus |first1=L. |last2=Norell |first2=M. |date=May 3, 2010 |publisher=University of California Press |isbn=978-0-520-94552-4 |pages=[https://archive.org/details/barnumbrownmanwh00ding/page/n106 90], 124}}</ref> The original ''Dynamosaurus'' material now resides in the collections of the [[Natural History Museum, London|Natural History Museum]], London.<ref name="Breithaupt">{{Cite journal |last1=Breithaupt |first1=B. H. |last2=Southwell |first2=E. H. |last3=Matthews |first3=N. A. |date=2006 |editor-last=Lucas |editor-first=S. G. |editor2-last=Sullivan |editor2-first=R. M. |title=''Dynamosaurus imperiosus'' and the earliest discoveries of ''Tyrannosaurus rex'' in Wyoming and the West |url=http://econtent.unm.edu/utils/getdownloaditem/collection/bulletins/id/693/filename/694.pdf/mapsto/pdf |format=PDF |journal=New Mexico Museum of Natural History and Science Bulletin |volume=35 |page=258 |quote=The original skeleton of ''Dynamosaurus imperiosus'' (AMNH 5866/BM R7995), together with other ''T. rex'' material (including parts of AMNH 973, 5027, and 5881), were sold to the British Museum of Natural History (now The Natural History Museum) in 1960. This material was used in an interesting 'half-mount' display of this dinosaur in London. Currently the material resides in the research collections. |archive-date=August 1, 2019 |access-date=June 25, 2015 |archive-url=https://web.archive.org/web/20190801022355/http://econtent.unm.edu/utils/getdownloaditem/collection/bulletins/id/693/filename/694.pdf/mapsto/pdf |url-status=live }}</ref> ''Dynamosaurus'' would later be honored by the 2018 description of another species of tyrannosaurid by Andrew McDonald and colleagues, ''[[Dynamoterror dynastes]]'', whose name was chosen in reference to the 1905 name, as it had been a "childhood favorite" of McDonald's.<ref name="McDonald2018">{{Cite journal |last1=McDonald |first1=A. T. |last2=Wolfe |first2=D. G. |last3=Dooley |first3=A. C. Jr. |date=2018 |title=A new tyrannosaurid (Dinosauria: Theropoda) from the Upper Cretaceous Menefee Formation of New Mexico |journal=PeerJ |volume=6 |page=6:e5749 |doi=10.7717/peerj.5749 |pmid=30324024|pmc=6183510 |doi-access=free  |issn = 2167-8359}}</ref>

From the 1910s through the end of the 1950s, Barnum's discoveries remained the only specimens of ''Tyrannosaurus'', as the [[Great Depression]] and wars kept many paleontologists out of the field.<ref name="larson2008" />

===Resurgent interest===
[[File:FMNH SUE Trex.jpg|alt=|thumb|Specimen "[[Sue (dinosaur)|Sue]]", [[Field Museum of Natural History]], Chicago]]
Beginning in the 1960s, there was renewed interest in ''Tyrannosaurus'', resulting in the recovery of 42 skeletons (5–80% complete by bone count) from Western North America.<ref name="larson2008" /> In 1967, Dr. William MacMannis located and recovered the skeleton named "MOR 008", which is 15% complete by bone count and has a reconstructed skull displayed at the [[Museum of the Rockies]]. The 1990s saw numerous discoveries, with nearly twice as many finds as in all previous years, including two of the most complete skeletons found to date: [[Sue (dinosaur)|Sue]] and [[Stan (dinosaur)|Stan]].<ref name="larson2008" />

[[Sue Hendrickson]], an [[amateur]] paleontologist, discovered the most complete (approximately 85%) and largest ''Tyrannosaurus'' skeleton in the [[Hell Creek Formation]] on August 12, 1990. The specimen Sue, named after the discoverer, was the object of a legal battle over its ownership. In 1997, the litigation was settled in favor of Maurice Williams, the original land owner. The fossil collection was purchased by the [[Field Museum of Natural History]] at auction for $7.6&nbsp;million, making it the most expensive dinosaur skeleton until the sale of Stan for $31.8 million in 2020.<ref>{{cite news |title=T. Rex Skeleton Brings $31.8 Million at Christie's Auction |url=https://www.nytimes.com/2020/10/06/arts/design/t-rex-skeleton-brings-31-8-million-at-christies-auction.html |archive-url=https://web.archive.org/web/20201007175400/https://www.nytimes.com/2020/10/06/arts/design/t-rex-skeleton-brings-31-8-million-at-christies-auction.html |archive-date=October 7, 2020 |url-access=subscription |url-status=live |website=The New York Times |date=October 7, 2020 |access-date=May 5, 2021|last1=Small |first1=Zachary }}</ref> From 1998 to 1999, Field Museum of Natural History staff spent over 25,000 hours taking the rock off the bones.<ref name="Sueprep">{{Cite web |url=http://archive.fieldmuseum.org/sue/?_ga=1.256723145.352611903.1414146341#preparing |title=Preparing Sue's bones |year=2007 |website=Sue at the Field Museum |publisher=The Field Museum |access-date=October 24, 2014 |archive-date=January 1, 2016 |archive-url=https://web.archive.org/web/20160101183701/http://archive.fieldmuseum.org/sue/?_ga=1.256723145.352611903.1414146341#preparing |url-status=live }}</ref> The bones were then shipped to [[New Jersey]] where the mount was constructed, then shipped back to Chicago for the final assembly. The mounted skeleton opened to the public on May 17, 2000, in the Field Museum of Natural History. A study of this specimen's fossilized bones showed that Sue reached full size at age 19 and died at the age of 28, the longest estimated life of any tyrannosaur known.<ref name="Ericksonetal2004TyrannosaurGigantism">{{Cite journal |last1=Erickson |first1=G. |last2=Makovicky |first2=P. J. |last3=Currie |first3=P. J. |last4=Norell |first4=M. |last5=Yerby |first5=S. |last6=Brochu |first6=C. A. |s2cid=4404887 |date=May 26, 2004 |title=Gigantism and life history parameters of tyrannosaurid dinosaurs |journal=Nature |volume=430 |issue=7001 |pages=772–775 |bibcode=2004Natur.430..772E |doi=10.1038/nature02699 |pmid=15306807 |url=http://doc.rero.ch/record/15279/files/PAL_E2578.pdf |archive-date=July 14, 2020 |access-date=November 23, 2022 |archive-url=https://web.archive.org/web/20200714024211/http://doc.rero.ch/record/15279/files/PAL_E2578.pdf |url-status=live }}{{Erratum|doi=10.1038/nature16487|pmid=26675726|http://retractionwatch.com/2016/03/01/high-profile-critic-slams-nature-letters-about-dinosaur-growth-following-corrections/ ''Retraction Watch''}}</ref> 
[[File:Scotty Tyrannosaurus.jpg|thumb|left|"[[Scotty (dinosaur)|Scotty]]", the largest known specimen, exhibited in Japan]]
Another ''Tyrannosaurus'', nicknamed Stan (BHI 3033), in honor of amateur paleontologist Stan Sacrison, was recovered from the Hell Creek Formation in 1992. Stan is the second most complete skeleton found, with 199 bones recovered representing 70% of the total.<ref>{{Cite web |url=http://www.museum.manchester.ac.uk/yourvisit/galleries/stan/ |title=Stan |date=September 18, 2010 |website=The University of Manchester |archive-url=https://web.archive.org/web/20100918104233/http://www.museum.manchester.ac.uk/yourvisit/galleries/stan/ |archive-date=September 18, 2010 }}</ref> This tyrannosaur also had many bone pathologies, including broken and healed ribs, a broken (and healed) neck, and a substantial hole in the back of its head, about the size of a ''Tyrannosaurus'' tooth.<ref>{{Cite book |title=''Tyrannosaurus'' Sue |url=https://archive.org/details/tyrannosaurussue00fiff_672 |url-access=limited |last=Fiffer |first=S. |publisher=W. H. Freeman and Company, New York |year=2000 |isbn=978-0-7167-4017-9 |pages=[https://archive.org/details/tyrannosaurussue00fiff_672/page/n139 121]–122 |chapter=Jurassic Farce}}</ref>

In 1998, 20-year-old Bucky Derflinger noticed a ''T. rex'' toe exposed above ground, making him the youngest person to discover a ''Tyrannosaurus''. The specimen, dubbed [[Specimens of Tyrannosaurus#"Bucky": TCM 2001.90.1|Bucky]] in honor of its discoverer, was a young adult, {{convert|10|ft|m|order=flip}} tall and {{convert|35|ft|m|order=flip}} long. Bucky is the first ''Tyrannosaurus'' to be found that preserved a [[furcula]] (wishbone). Bucky is permanently displayed at [[The Children's Museum of Indianapolis]].<ref>{{cite web|url=https://www.childrensmuseum.org/blog/meet-bucky-the-teenage-t-rex-v2 |date=July 7, 2014 |title=Meet Bucky The Teenage T. Rex |work=[[The Children's Museum of Indianapolis|Children's Museum of Indianapolis]] |access-date=December 2, 2019 |url-status=live |archive-url=https://web.archive.org/web/20141227210245/http://www.childrensmuseum.org/blog/meet-bucky-the-teenage-t-rex-v2 |archive-date=December 27, 2014}}</ref>
[[File:Tyrannosaurus specimens.svg|thumb|The specimens "Sue", AMNH 5027, "Stan", and "Jane", to scale with a human.]]
In the summer of 2000, crews organized by [[Jack Horner (paleontologist)|Jack Horner]] discovered five ''Tyrannosaurus'' skeletons near the [[Fort Peck Reservoir]].<ref name="bbc-horner">{{cite news |url=http://news.bbc.co.uk/2/hi/science/nature/965609.stm |title=Dig pulls up five T. rex specimens |date=October 10, 2000 |access-date=December 13, 2008 |work=BBC News |archive-date=August 19, 2018 |archive-url=https://web.archive.org/web/20180819045859/http://news.bbc.co.uk/2/hi/science/nature/965609.stm |url-status=live }}</ref> In 2001, a 50% complete skeleton of a juvenile ''Tyrannosaurus'' was discovered in the Hell Creek Formation by a crew from the [[Burpee Museum of Natural History]]. Dubbed Jane (BMRP 2002.4.1), the find was thought to be the first known skeleton of a [[pygmy]] tyrannosaurid, ''[[Nanotyrannus]]'', but subsequent research revealed that it is more likely a juvenile ''Tyrannosaurus'', and the most complete juvenile example known;<ref name="currieetal2003">{{Cite journal |last1=Currie |first1=P. J. |last2=Hurum |first2=J. H. |last3=Sabath |first3=K. |date=2003 |title=Skull structure and evolution in tyrannosaurid dinosaurs |url=http://www.app.pan.pl/archive/published/app48/app48-227.pdf |journal=Acta Palaeontologica Polonica |volume=48 |issue=2 |pages=227–234 |access-date=October 8, 2008 |archive-date=October 31, 2008 |archive-url=https://web.archive.org/web/20081031093118/http://www.app.pan.pl/archive/published/app48/app48-227.pdf |url-status=live }}</ref> Jane is exhibited at the Burpee Museum of Natural History.<ref>{{cite magazine |url=https://www.smithsonianmag.com/science-nature/tiny-terror-controversial-dinosaur-species-just-awkward-tween-tyrannosaurus-180957084/ |title=Tiny terror: Controversial dinosaur species is just an awkward tween ''Tyrannosaurus'' |last=Black |first=Riley |date=October 28, 2015 |magazine=Smithsonian Magazine |access-date=December 10, 2018 |archive-date=December 11, 2018 |archive-url=https://web.archive.org/web/20181211010200/https://www.smithsonianmag.com/science-nature/tiny-terror-controversial-dinosaur-species-just-awkward-tween-tyrannosaurus-180957084/ |url-status=live }}</ref> In 2002, a skeleton nicknamed "Wyrex", discovered by amateur collectors Dan Wells and Don Wyrick, had 114 bones and was 38% complete. The dig was concluded over 3 weeks in 2004 by the [[Black Hills Institute]] with the first live [[online]] ''Tyrannosaurus'' excavation providing daily reports, photos, and video.<ref name="larson2008" />

In 2006, [[Montana State University]] revealed that it possessed the largest ''Tyrannosaurus'' skull yet discovered (from a specimen named MOR 008), measuring {{convert|5|ft|cm|0|sp=us}} long.<ref name =MOR008>{{Cite web |url=http://www.montana.edu/cpa/news/nwview.php?article=3607 |title=Museum unveils world's largest ''T-rex'' skull. |date=2006 |archive-url=https://web.archive.org/web/20060414021235/http://www.montana.edu/cpa/news/nwview.php?article=3607 |archive-date=April 14, 2006 |access-date=April 7, 2006}}</ref> Subsequent comparisons indicated that the longest head was {{convert|136.5|cm|in}} (from specimen LACM 23844) and the widest head was {{convert|90.2|cm|in}} (from Sue).<ref name="gignac">{{Cite journal |last1=Gignac |first1=P. M. |last2=Erickson |first2=G. M. |year=2017 |title=The biomechanics behind extreme osteophagy in ''Tyrannosaurus rex'' |journal=Scientific Reports |volume=7 |issue=1 |page=2012 |bibcode=2017NatSR...7.2012G |doi=10.1038/s41598-017-02161-w |pmc=5435714 |pmid=28515439}}</ref>

===Footprints===
[[File:Philmont T-Rex 2022.jpg|left|thumb|Probable footprint from [[New Mexico]]]]
Two isolated fossilized [[footprint]]s have been tentatively assigned to ''T. rex''. The first was discovered at [[Philmont Scout Ranch]], New Mexico, in 1983 by American geologist Charles Pillmore. Originally thought to belong to a [[hadrosaurid]], examination of the footprint revealed a large 'heel' unknown in [[ornithopod]] dinosaur tracks, and traces of what may have been a [[hallux]], the dewclaw-like fourth digit of the tyrannosaur foot. The footprint was published as the [[ichnogenus]] ''[[Tyrannosauripus pillmorei]]'' in 1994, by [[Martin Lockley]] and Adrian Hunt. Lockley and Hunt suggested that it was very likely the track was made by a ''T. rex'', which would make it the first known footprint from this species. The track was made in what was once a vegetated wetland mudflat. It measures {{convert|83|cm|in|sp=us}} long by {{convert|71|cm|in|sp=us}} wide.<ref name="lockley&hunt1994">{{Cite journal |last1=Lockley |first1=M. G. |last2=Hunt |first2=A. P. |year=1994 |title=A track of the giant theropod dinosaur ''Tyrannosaurus'' from close to the Cretaceous/Tertiary boundary, northern New Mexico |journal=Ichnos |volume=3 |issue=3 |pages=213–218  |doi=10.1080/10420949409386390|bibcode=1994Ichno...3..213L }}</ref>

A second footprint that may have been made by a ''Tyrannosaurus'' was first reported in 2007 by British paleontologist Phil Manning, from the [[Hell Creek Formation]] of Montana. This second track measures {{convert|72|cm|in|sp=us}} long, shorter than the track described by Lockley and Hunt. Whether or not the track was made by ''Tyrannosaurus'' is unclear, though ''Tyrannosaurus'' is the only large theropod known to have existed in the Hell Creek Formation.<ref name="rextrack2007">{{Cite web |url=http://www.nhm.ac.uk/about-us/news/2007/october/news_12515.html |title=A Probable Tyrannosaurid Track From the Hell Creek Formation (Upper Cretaceous), Montana, United States |year=2007 |website=National Museum of History News  |access-date=December 18, 2007 |archive-url=https://web.archive.org/web/20071214014855/http://www.nhm.ac.uk/about-us/news/2007/october/news_12515.html |archive-date=December 14, 2007 }}</ref><ref name="manningetal2008">{{Cite journal |last1=Manning |first1=P. L. |last2=Ott |first2=C. |last3=Falkingham |first3=P. L. |s2cid=129985735 |year=2009 |title=The first tyrannosaurid track from the Hell Creek Formation (Late Cretaceous), Montana, U.S.A |journal=PALAIOS |volume=23 |issue=10 |pages=645–647 |bibcode=2008Palai..23..645M |doi=10.2110/palo.2008.p08-030r}}</ref>

A set of footprints in Glenrock, Wyoming dating to the [[Maastrichtian]] stage of the Late Cretaceous and hailing from the [[Lance Formation]] were described by Scott Persons, Phil Currie and colleagues in 2016, and are believed to belong to either a juvenile ''T. rex'' or the dubious tyrannosaurid ''Nanotyrannus lancensis''. From measurements and based on the positions of the footprints, the animal was believed to be traveling at a walking speed of around 2.8 to 5 miles per hour and was estimated to have a hip height of {{convert|1.56|to|2.06|m|ft|abbr=on}}.<ref>{{Cite journal |last1=Smith |first1=S. D. |last2=Persons |first2=W. S. |last3=Xing |first3=L. |year=2016 |title=A "Tyrannosaur" trackway at Glenrock, Lance Formation (Maastrichtian), Wyoming |url=https://www.sciencedaily.com/releases/2016/01/160116214746.htm |journal=Cretaceous Research |volume=61 |issue=1 |pages=1–4 |doi=10.1016/j.cretres.2015.12.020 |bibcode=2016CrRes..61....1S |archive-date=July 11, 2019 |access-date=March 9, 2018 |archive-url=https://web.archive.org/web/20190711130653/https://www.sciencedaily.com/releases/2016/01/160116214746.htm |url-status=live }}</ref><ref>{{Cite journal |last=Perkins |first=S. |year=2016 |title=You could probably have outrun a ''T. rex'' |url=https://www.science.org/content/article/you-could-probably-have-outrun-t-rex |journal=Palaeontology |doi=10.1126/science.aae0270 |archive-date=October 3, 2022 |access-date=June 30, 2022 |archive-url=https://web.archive.org/web/20221003205139/https://www.science.org/content/article/you-could-probably-have-outrun-t-rex |url-status=live }}</ref><ref>{{cite news |url=https://www.usatoday.com/story/news/2016/01/27/tyrannosaurs-faster-than-velociraptors/79423372/ |title=Forget all you know from Jurassic Park: For speed, ''T. rex'' beats ''velociraptor''s |last=Walton |first=T. |access-date=March 13, 2016 |newspaper=USA Today |year=2016 |archive-date=August 19, 2018 |archive-url=https://web.archive.org/web/20180819045903/https://www.usatoday.com/story/news/2016/01/27/tyrannosaurs-faster-than-velociraptors/79423372/ |url-status=live }}</ref> A follow-up paper appeared in 2017, increasing the speed estimations by 50–80%.<ref>{{Cite journal |last=Ruiz |first=J. |year=2017 |title=Comments on "A tyrannosaur trackway at Glenrock, Lance Formation (Maastrichtian), Wyoming" (Smith et al., ''Cretaceous Research'', v. 61, pp. 1–4, 2016) |journal=Cretaceous Research |volume=82 |pages=81–82 |doi=10.1016/j.cretres.2017.05.033}}</ref>