MONTAGNE: Bits of melanin are found inside cells, and the shape of those bits says something about the color of the creature. Main article: Feathered dinosaur Fossilized skin impressions from the tail region of a Tyrannosaurus, Houston Museum of Natural Science

Woodward, Holly N; Tremaine, Katie; Williams, Scott A; Zanno, Lindsay E; Horner, John R; Myhrvold, Nathan (January 1, 2020). "Growing up Tyrannosaurus rex: Osteohistology refutes the pygmy "Nanotyrannus" and supports ontogenetic niche partitioning in juvenile Tyrannosaurus". Science Advances. 6 (1): eaax6250. Bibcode: 2020SciA....6.6250W. doi: 10.1126/sciadv.aax6250. PMC 6938697. PMID 31911944. Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to its large and powerful hind limbs, the forelimbs of Tyrannosaurus were short but unusually powerful for their size, and they had two clawed digits. The most complete specimen measures up to 12.3–12.4m (40–41ft) in length, but according to most modern estimates, Tyrannosaurus could have exceeded sizes of 13m (43ft) in length, 3.7–4m (12–13ft) in hip height, and 8 tonnes (7.9 long tons; 8.8 short tons) in mass. Although many other theropods likely rivaled Tyrannosaurus in size, it is still among the largest known land predators and is estimated to have exerted the strongest bite force among all terrestrial animals. By far the largest carnivore in its environment, Tyrannosaurus rex was most likely an apex predator, preying upon hadrosaurs, juvenile armored herbivores like ceratopsians and ankylosaurs, and possibly sauropods. Some experts have suggested the dinosaur was primarily a scavenger. The question of whether Tyrannosaurus was an apex predator or a pure scavenger was among the longest debates in paleontology. Most paleontologists today accept that Tyrannosaurus was both an active predator and a scavenger. In 2016, analysis of limb proportions by Persons and Currie suggested Nanotyrannus specimens to have differing cursoriality levels, potentially separating it from T. rex. [88] However, paleontologist Manabu Sakomoto has commented that this conclusion may be impacted by low sample size, and the discrepancy does not necessarily reflect taxonomic distinction. [89] In 2016, Joshua Schmerge argued for Nanotyrannus' validity based on skull features, including a dentary groove in BMRP 2002.4.1's skull. According to Schmerge, as that feature is absent in T. rex and found only in Dryptosaurus and albertosaurines, this suggests Nanotyrannus is a distinct taxon within the Albertosaurinae. [90] The same year, Carr and colleagues noted that this was not sufficient enough to clarify Nanotyrannus' validity or classification, being a common and ontogenetically variable feature among tyrannosauroids. [91]McDonald, A. T.; Wolfe, D. G.; Dooley, A. C. Jr. (2018). "A new tyrannosaurid (Dinosauria: Theropoda) from the Upper Cretaceous Menefee Formation of New Mexico". PeerJ. 6: 6:e5749. doi: 10.7717/peerj.5749. PMC 6183510. PMID 30324024. The Mega Neon T-Rex cycles through the colors of the rainbow in the same parts where it glows when Neon. a b Carr, T.D. (1999). "Craniofacial ontogeny in Tyrannosauridae (Dinosauria, Coelurosauria)". Journal of Vertebrate Paleontology. 19 (3): 497–520. Bibcode: 1999JVPal..19..497C. doi: 10.1080/02724634.1999.10011161. S2CID 83744433. Perkins, S. (2016). "You could probably have outrun a T. rex". Palaeontology. doi: 10.1126/science.aae0270. Several notable Tyrannosaurus remains have been found in the Hell Creek Formation. During the Maastrichtian this area was subtropical, with a warm and humid climate. The flora consisted mostly of angiosperms, but also included trees like dawn redwood ( Metasequoia) and Araucaria. Tyrannosaurus shared this ecosystem with ceratopsians Leptoceratops, Torosaurus, and Triceratops, the hadrosaurid Edmontosaurus annectens, the parksosaurid Thescelosaurus, the ankylosaurs Ankylosaurus and Denversaurus, the pachycephalosaurs Pachycephalosaurus and Sphaerotholus, and the theropods Ornithomimus, Struthiomimus, Acheroraptor, Dakotaraptor, Pectinodon and Anzu. [222]

Other tyrannosaurid fossils found in the same formations as T. rex were originally classified as separate taxa, including Aublysodon and Albertosaurus megagracilis, [61] the latter being named Dinotyrannus megagracilis in 1995. [76] These fossils are now universally considered to belong to juvenile T. rex. [77] A small but nearly complete skull from Montana, 60 centimeters (2.0ft) long, might be an exception. This skull, CMNH 7541, was originally classified as a species of Gorgosaurus ( G. lancensis) by Charles W. Gilmore in 1946. [78] In 1988, the specimen was re-described by Robert T. Bakker, Phil Currie, and Michael Williams, then the curator of paleontology at the Cleveland Museum of Natural History, where the original specimen was housed and is now on display. Their initial research indicated that the skull bones were fused, and that it therefore represented an adult specimen. In light of this, Bakker and colleagues assigned the skull to a new genus named Nanotyrannus (meaning "dwarf tyrant", for its apparently small adult size). The specimen is estimated to have been around 5.2 meters (17ft) long when it died. [79] However, In 1999, a detailed analysis by Thomas Carr revealed the specimen to be a juvenile, leading Carr and many other paleontologists to consider it a juvenile T. rex individual. [80] [81] Reconstructed skeleton of "Jane", Burpee Museum of Natural History terrestrial taxa such as tyrannosaurids and Neovenator may have had average facial sensitivity for non-edentulous terrestrial theropods, although further research is needed. The neurovascular canals in Tyrannosaurus may instead have supported soft tissue structures for thermoregulation or social signaling, the latter of which could be confirmed by the fact that the neurovascular network of canals may have changed during ontogeny. [169] a b Holtz, T. R. Jr. (2004). "Tyrannosauroidea". In Weishampel, D. B.; Dodson, P.; Osmólska, H. (eds.). The dinosauria. Berkeley: University of California Press. pp. 111–136. ISBN 978-0-520-24209-8.Lipkin, C.; Carpenter, K. (2008). "Looking again at the forelimb of Tyrannosaurus rex". In Carpenter, K.; Larson, P. E. (eds.). Tyrannosaurus rex , the Tyrant King. Bloomington: Indiana University Press. pp. 167–190. ISBN 978-0-253-35087-9. Bakker, R.T.; Williams, M.; Currie, P.J. (1988). " Nanotyrannus, a new genus of pygmy tyrannosaur, from the latest Cretaceous of Montana". Hunteria. 1: 1–30. a b c d Carr, T. D.; Varricchio, D. J.; Sedlmayr, J. C.; Roberts, E. M.; Moore, J. R. (March 30, 2017). "A new tyrannosaur with evidence for anagenesis and crocodile-like facial sensory system". Scientific Reports. 7: 44942. Bibcode: 2017NatSR...744942C. doi: 10.1038/srep44942. ISSN 2045-2322. PMC 5372470. PMID 28358353. The Giganotosaurus was the only main antagonist in the Jurassic World trilogy that Blue didn't meet.