What did Tyrannosaurus rex really look like?
Tyrannosaurus rex is known from many skeletons but very little soft tissue, so its skin, lips, posture and bulk have all been argued over. Fossil skin patches, feathered relatives, bone textures and tooth wear each point in different directions.
5 established, 5 disputed, 2 debunked, 2 unresolved. We do not pick an answer; the evidence places each claim. How we decide
41 citations from 13 independent sources - 28 echo the same voices and count once. Graded A1-D1.
Added 29 Sept 2026
What the four states mean
- Establishedsupported, uncontested
- Disputedcredible sources disagree
- Debunkedrefuted by the evidence
- Unresolvedno settled answer
Established 5supported, uncontested
Fossil skin described from Tyrannosaurus and other tyrannosaurids is scaly.▰▰▰▱▱ likely3 points
Supports- We describe fossil integument from Tyrannosaurus and other tyrannosaurids ( Albertosaurus, Daspletosaurus, Gorgosaurus and Tarbosaurus ), confirming that these large-bodied forms possessed scaly, reptilian-like skin.Bell, Campione, Persons, Currie, Larson, Tanke and Bakker 2017, Tyrannosauroid integument reveals conflicting patterns of gigantism and feather evolution, Biology Letters 13: 20170092 authoritative
- Each patch shows the same skin type: uniform, tiny 'basement scales', each less than 1 mm acrossMark P. Witton, Revenge of the scaly Tyrannosaurus, Mark P. Witton's Blog, June 2017 analysis
- The preservation of scales on tyrannosaurs shows that they had scales, just like any other dinosaurs.Riley Black, Long Live the Fuzzy T. rex, Scientific American (Laelaps blog), 2017 analysis
In drawings of T. rex by college and school students, the spine sat at an average angle of 50 to 60 degrees, within about 5 degrees of the 1905 posture at 57 degrees.▰▰▰▱▱ likely2 points
Supports- An average angle of 50-60° was found in drawings from all ages, which is within about 5° of the 1905 posture at 57°.Ross, Duggan-Haas and Allmon 2013, The Posture of Tyrannosaurus rex: Why Do Student Views Lag Behind the Science?, Journal of Geoscience Education 61: 145-160 (abstract) authoritative
- Within a sample of 111 Ithaca College undergraduates and 205 elementary to middle school students who visited the Paleontological Research Institution in Ithaca, New York, students most often drew T. rex with a spinal angle of over 40°, with the college students being more likely to draw the dinosaur with the incorrect posture than precollege students.Riley Black, Drawing Tyrannosaurus: You're Probably Doing it Wrong, National Geographic (Laelaps blog) summary
Yutyrannus huali, a gigantic basal tyrannosauroid from the Lower Cretaceous of China, bore long filamentous feathers.▰▰▰▱▱ likely3 points
Supports- Here we report the discovery of a gigantic new basal tyrannosauroid, Yutyrannus huali gen. et sp. nov., based on three nearly complete skeletons representing two distinct ontogenetic stages from the Lower Cretaceous Yixian Formation of Liaoning Province, China.Xu, Wang, Zhang et al. 2012, A gigantic feathered dinosaur from the Lower Cretaceous of China, Nature 484: 92-95 authoritative
- Most significantly, Y. huali bears long filamentous feathers, thus providing direct evidence for the presence of extensively feathered gigantic dinosaurs and offering new insights into early feather evolution.Xu, Wang, Zhang et al. 2012, A gigantic feathered dinosaur from the Lower Cretaceous of China, Nature 484: 92-95 authoritative
- Filamentous feathers have been described in two tyrannosauroids, both from the Early Cretaceous of China: Dilong paradoxus [ 8 ] and Yutyrannus hualiBell, Campione, Persons, Currie, Larson, Tanke and Bakker 2017, Tyrannosauroid integument reveals conflicting patterns of gigantism and feather evolution, Biology Letters 13: 20170092 authoritative
A computational study of scanned skeletons concluded that adult T. rex had body masses around 6000 to 8000 kg, with the largest known specimen, Sue, perhaps about 9500 kg.▰▰▱▱▱ likely2 points
Supports- Although those problems cause ambiguity, we conclude that adult T. rex had body masses around 6000-8000 kg, with the largest known specimen (“Sue”) perhaps ∼9500 kg.Hutchinson, Bates, Molnar, Allen and Makovicky 2011, A Computational Analysis of Limb and Body Dimensions in Tyrannosaurus rex with Implications for Locomotion, Ontogeny, and Growth, PLoS ONE 6(10): e26037 authoritative
- Here we address these questions using three-dimensionally scanned computer models of four large, well-preserved fossil specimens as well as a putative juvenile individual.Hutchinson, Bates, Molnar, Allen and Makovicky 2011, A Computational Analysis of Limb and Body Dimensions in Tyrannosaurus rex with Implications for Locomotion, Ontogeny, and Growth, PLoS ONE 6(10): e26037 authoritative
A skeletally mature T. rex specimen, RSM P2523.8, has an estimated body mass exceeding all other known T. rex specimens.▰▰▱▱▱ likely3 points
Supports- Here we describe an extremely large and relatively complete (roughly 65%) skeleton of Tyrannosaurus rex (RSM P2523.8).Persons, Currie and Erickson 2020, An Older and Exceptionally Large Adult Specimen of Tyrannosaurus rex, The Anatomical Record 303: 656-672 (abstract) authoritative
- Multiple measurements (including those of the skull, hip, and limbs) show that RSM P2523.8 was a robust individual with an estimated body mass exceeding all other known T. rex specimens and representatives of all other gigantic terrestrial theropods.Persons, Currie and Erickson 2020, An Older and Exceptionally Large Adult Specimen of Tyrannosaurus rex, The Anatomical Record 303: 656-672 (abstract) authoritative
- Histological sampling of the fibula confirms that RSM P2523.8 is skeletally mature.Persons, Currie and Erickson 2020, An Older and Exceptionally Large Adult Specimen of Tyrannosaurus rex, The Anatomical Record 303: 656-672 (abstract) authoritative
Disputed 5credible sources disagree
Feathery integument may have been present on parts of the T. rex body not covered by the known scaly skin patches.▰▰▰▱▱ likely2 against4 points
Supports- So even if assume for a moment that the new study is correct and the rare patches of tyrannosaur skin really do represent a body surface of scales, not a wisp of feather in sight, it doesn’t mean that feathery integument wasn’t present elsewhere on the body.Riley Black, Long Live the Fuzzy T. rex, Scientific American (Laelaps blog), 2017 analysis
- if partly feathered, these were limited to the dorsum.Bell, Campione, Persons, Currie, Larson, Tanke and Bakker 2017, Tyrannosauroid integument reveals conflicting patterns of gigantism and feather evolution, Biology Letters 13: 20170092 authoritative
Against- Palaeontologists have to work with data, not suspicions or gut feelings, and the data we have does not include, or hint at, the presence of filaments.Mark P. Witton, Revenge of the scaly Tyrannosaurus, Mark P. Witton's Blog, June 2017 analysis
- For the time being, wholly scale models fit our existing data just as reasonably as partly fuzzy onesMark P. Witton, Revenge of the scaly Tyrannosaurus, Mark P. Witton's Blog, June 2017 analysis
The loss of extensive feather coverings in tyrannosaurids was possibly tied to the evolution of gigantism.▰▰▰▱▱ likely1 against3 points
Supports- This loss is unrelated to palaeoclimate but possibly tied to the evolution of gigantism, although other mechanisms exist.Bell, Campione, Persons, Currie, Larson, Tanke and Bakker 2017, Tyrannosauroid integument reveals conflicting patterns of gigantism and feather evolution, Biology Letters 13: 20170092 authoritative
- In light of this, the reduction of filamented regions, and perhaps lessening their density, is a reasonable inference for animals of the size and habitat of Tyrannosaurus, and would reflect thermoregulatory responses to scaling and shade availability seen in living animals.Mark P. Witton, Revenge of the scaly Tyrannosaurus, Mark P. Witton's Blog, June 2017 analysis
Against- Lacking fuzz might not have really saved T. rex very much trouble at its size.Riley Black, Long Live the Fuzzy T. rex, Scientific American (Laelaps blog), 2017 analysis
When the mouth was closed, the teeth of Tyrannosaurus rex and other theropods were completely covered by extraoral tissue.▰▰▰▱▱ likely2 against4 points
Supports- Analyses of dental histology from crocodylians and theropod dinosaurs, including Tyrannosaurus rex , further indicate that the most likely condition was complete coverage of the marginal dentition with extraoral tissue when the mouth was closed.Cullen, Larson, Witton, Scott, Maho, Brink, Evans and Reisz 2023, Theropod dinosaur facial reconstruction and the importance of soft tissues in paleobiology, Science 379: 1348-1352 (abstract) authoritative
- According to Cullen et al. , in contrast to their closest toothed crocodilian relatives, theropod teeth lacked any evidence of outer surface wear, indicating the existence of extraoral tissues and oral secretions needed to keep them hydrated and protected from exposure.AAAS news release on Cullen et al. 2023, Theropod dinosaur teeth were hidden behind thin lips, EurekAlert summary
Against- The new study “can be summed up in two words: completely unconvincing,” says Carr, of Carthage College in Kenosha, Wisc.Jake Buehler, T. rex may have had lips like a modern lizard's, Science News, 2023 (quoting Thomas Cullen and Thomas Carr) summary
- The new research “completely disregards … the texture of the facial bones, which unambiguously shows that [tyrannosaurs] had flat scales, like in crocodilians, all the way down to the edges of the jaws.”Jake Buehler, T. rex may have had lips like a modern lizard's, Science News, 2023 (quoting Thomas Cullen and Thomas Carr) summary
Variation in Tyrannosaurus bones and teeth, combined with stratigraphy, indicates three potential groups that could be named as two new species, T. imperator and T. regina, alongside T. rex.▰▰▰▱▱ roughly even chance2 against4 points
Supports- The authors conclude that the physical variation found in Tyrannosaurus specimens combined with their stratigraphy are indicative of three potential groups that could be nominated as two new species, T. imperator and T. regina , alongside the only recognised species to date, T. rex .Springer news release on Paul, Persons and Van Raalte 2022, The Tyrant Lizard King, Queen and Emperor (Evolutionary Biology), via ScienceDaily summary
- A new analysis of Tyrannosaurus skeletal remains reveals physical differences in the femur, other bones and dental structures across specimens that could suggest Tyrannosaurus rex specimens need to be re-categorised into three distinct groups or speciesSpringer news release on Paul, Persons and Van Raalte 2022, The Tyrant Lizard King, Queen and Emperor (Evolutionary Biology), via ScienceDaily summary
Against- The results showed that the absolute variation in Tyrannosaurus is unexceptional and it does not indicate cryptic diversity.Carr, Napoli, Brusatte, Holtz, Hone, Williamson and Zanno 2022, Insufficient Evidence for Multiple Species of Tyrannosaurus in the Latest Cretaceous of North America, Evolutionary Biology (abstract) authoritative
- We conclude that “T. regina” and “T. imperator” are subjective junior synonyms of T. rex.Carr, Napoli, Brusatte, Holtz, Hone, Williamson and Zanno 2022, Insufficient Evidence for Multiple Species of Tyrannosaurus in the Latest Cretaceous of North America, Evolutionary Biology (abstract) authoritative
The coarse texture of tyrannosaurid facial bones indicates a face covered mainly in flat scales, as in crocodylians.▰▰▰▱▱ unlikely2 against3 points
Supports- The coarse texture shared between tyrannosaurids and crocodylians indicates a primary covering of flat scales on the face of the nonavian dinosaurs ( Fig. 4 ).Carr, Varricchio, Sedlmayr, Roberts and Moore 2017, A new tyrannosaur with evidence for anagenesis and crocodile-like facial sensory system, Scientific Reports 7: 44942 authoritative
Against- crocodylians do not have face scales, but a tight, highly cracked sheet of facial skin - Milinkovitch et al. (2013).Mark P. Witton, Revenge of the scaly Tyrannosaurus, Mark P. Witton's Blog, June 2017 analysis
- This bone roughness isn’t a consistent feature in theropods, Cullen says. Young tyrannosaurs and smaller theropod species had smooth bones similar to a lizard’s.Jake Buehler, T. rex may have had lips like a modern lizard's, Science News, 2023 (quoting Thomas Cullen and Thomas Carr) summary
Debunked 2refuted by the evidence
Tyrannosaurus rex stood in an upright, tail-dragging posture, as in the original 1905 description of the dinosaur.Refuted by
This is in striking contrast to images created by modern dinosaur scientists, which average between 0 and 10°.
refuted2 against3 pointsThe claim rested on- if asked to draw a picture of Tyrannosaurus rex, most of these students will likely draw an animal with an upright, tail-dragging posture, remarkably like the original 1905 description of this famous dinosaur.Ross, Duggan-Haas and Allmon 2013, The Posture of Tyrannosaurus rex: Why Do Student Views Lag Behind the Science?, Journal of Geoscience Education 61: 145-160 (abstract) authoritative
Refuted by- This is in striking contrast to images created by modern dinosaur scientists, which average between 0 and 10°.Ross, Duggan-Haas and Allmon 2013, The Posture of Tyrannosaurus rex: Why Do Student Views Lag Behind the Science?, Journal of Geoscience Education 61: 145-160 (abstract) authoritative
- We hypothesize that older-style images long embedded in pop culture could lead to cultural inertia, in which outdated scientific ideas are maintained in the public consciousness long after scientists have abandoned them.Ross, Duggan-Haas and Allmon 2013, The Posture of Tyrannosaurus rex: Why Do Student Views Lag Behind the Science?, Journal of Geoscience Education 61: 145-160 (abstract) authoritative
Speculation following feathered theropod finds held that the largest tyrannosaurids, including Tyrannosaurus rex, were extensively feathered.Refuted by
suggesting that most (if not all) large-bodied tyrannosaurids were scaly and, if partly feathered, these were limited to the dorsum.
refuted2 against3 pointsThe claim rested on- Recent evidence for feathers in theropods has led to speculations that the largest tyrannosaurids, including Tyrannosaurus rex , were extensively feathered.Bell, Campione, Persons, Currie, Larson, Tanke and Bakker 2017, Tyrannosauroid integument reveals conflicting patterns of gigantism and feather evolution, Biology Letters 13: 20170092 authoritative
Refuted by- suggesting that most (if not all) large-bodied tyrannosaurids were scaly and, if partly feathered, these were limited to the dorsum.Bell, Campione, Persons, Currie, Larson, Tanke and Bakker 2017, Tyrannosauroid integument reveals conflicting patterns of gigantism and feather evolution, Biology Letters 13: 20170092 authoritative
- A thick coat of protoplumage might be out of the questionRiley Black, Long Live the Fuzzy T. rex, Scientific American (Laelaps blog), 2017 analysis
Unresolved 2no settled answer
Scaly skin on a large adult does not rule out that younger tyrannosaurs possessed feathers.▰▰▰▱▱ likely2 points
Supports- Finally, the presence of epidermal scales in a large adult individual does not rule out the possibility that younger individuals possessed feathersBell, Campione, Persons, Currie, Larson, Tanke and Bakker 2017, Tyrannosauroid integument reveals conflicting patterns of gigantism and feather evolution, Biology Letters 13: 20170092 authoritative
- If so, Tyannosaurus could have changed appearance considerably with age (fluffy when small, scaly when big - above) or season (reflecting changes in climate or behaviour)?Mark P. Witton, Revenge of the scaly Tyrannosaurus, Mark P. Witton's Blog, June 2017 analysis
A discovery such as a mummified tyrannosaur carcass with preserved facial tissues could settle which of these dinosaurs had lips.▰▰▰▱▱ likely2 points
Supports- Something like the discovery of a mummified tyrannosaur carcass with preserved facial tissues, Carr says, could settle the matter of who had lips and who didn’tJake Buehler, T. rex may have had lips like a modern lizard's, Science News, 2023 (quoting Thomas Cullen and Thomas Carr) summary
- its soft-tissues - and thus much about its life appearance - are poorly represented by fossil remains.Mark P. Witton, Revenge of the scaly Tyrannosaurus, Mark P. Witton's Blog, June 2017 analysis
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