Tyrannosaurus rex
Tyrannosaurus is a genus of large theropod dinosaur. The type species Tyrannosaurus rex, often shortened to T. rex or colloquially T-Rex, is one of the best represented theropods. It lived throughout what is now western North America, on what was then an island continent known as Laramidia. Tyrannosaurus had a much wider range than other tyrannosaurids. Fossils are found in a variety of geological formations which have been dated to the late Maastrichtian age of the late Cretaceous period, 69 to 66 million years ago, with isolated specimens possibly indicating an earlier origin in the middle Campanian age. It was one of the last known members of the tyrannosaurids and among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event.

ScottRobertAnselmo · CC BY-SA 3.0 · via Wikipedia/Commons. May be a photograph of a specimen, or an artist’s reconstruction — an interpretation of a skeleton, since colour and soft tissue are almost never preserved.
On record
Recorded, not inferred- Also called
- tyrant lizard kingPBDB
- Sits inside
- TyrannosaurusPBDB
- Diet
- carnivorePBDB, for Coelurosauria
- Life habit
- ground dwelling, solitaryPBDB, for Theropoda
- Motility
- actively mobilePBDB, for Theropoda
- Environment
- terrestrialPBDB, for Theropoda
- Length
- 40 footWikidata
- Mass
- 20000 poundWikidata
Time the record covers
At most 18 million years on record.
Every occurrence read is dated to somewhere between 83.6 Mya and 66 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.
70 occurrences of Tyrannosaurus rex on record, most of them in the Late Cretaceous. Bar height is expected occurrences, not a count: each fossil is spread across the span it is dated to, so a tall narrow bar means tight dating and a low wide one means loose.
When
70 occurrences- Late Cretaceous100%
These are dates about fossils, not the animal: the record can only begin after it arose and end before it died out, so either end may reach further. Shares are expected occurrences: a fossil dated to a span is counted partly in each period it straddles. More on what this infers.
Found in
11 formations
- Hell Creek Formation · Montana Group43
- Lance Formation10
- Denver Formation5
- Ferris Formation4
- Scollard Formation · Edmonton Group2
- Dinosaur Park Formation · Belly River Group1
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The named rock units Tyrannosaurus rex has been recovered from, largest first. Drawn where the rock is now, not where it formed.
Tyrannosaurus rex and its relatives
Late CretaceousWhere Tyrannosaurus rex and its relatives were recorded in the Late Cretaceous.
Found in the same rock
309 taxa- Trionychidae28 sites
- Champsosaurus24 sites
- Cyclurus fragosus24 sites
- Brachychampsa montana23 sites
- Borealosuchus sternbergii22 sites
- Myledaphus bipartitus22 sites
- Ceratopsidae21 sites
- Lepisosteus occidentalis21 sites
- Baenidae19 sites
- Compsemys victa18 sites
- Adocus17 sites
- Hadrosaurinae17 sites
- Paronychodon16 sites
- Richardoestesia isosceles15 sites
- Scapherpeton tectum15 sites
- Triceratops15 sites
- Helopanoplia beecheri14 sites
- Lonchidion selachos14 sites
- Aves13 sites
- Caudata13 sites
- Melvius thomasi13 sites
- Chelydridae12 sites
- Lepidosauria12 sites
- Opisthotriton kayi11 sites
The Paleobiology Database records 68 sites for Tyrannosaurus rex, and this reads all of them. The number is how many of those sites it was catalogued from too. The 24 sharing the most are listed.
This is not a list of everything alive at the time. It is only what has come out of the same ground as this animal and been written down.
Entered from
30 references- Vertebrate biostratigraphy of the Hell Creek Formation in southwestern North Dakota and northwestern South Dakota23
- The tyrant lizard king, queen and emperor: multiple lines of morphological and stratigraphic evidence support subtle evolution and probable speciation within the North American genus Tyrannosaurus7
- Late Cretaceous dinosaurs from the Denver Basin, Colorado4
- Vertebrate faunal changes through Lancian and Puercan time in southern Wyoming4
- Fossil vertebrates from the Late Cretaceous Lance Formation, eastern Wyoming3
- Patterns of geographic variation in latest Cretaceous vertebrates: evidence from the turtle component2
- Paul, 19882
- Extinct mammals, birds, reptiles and fishes2
- Tyrannosaurus and other Cretaceous carnivorous dinosaurs2
- Preliminary report on the mammals form Lane's Little Jaw Site Quarry: a latest Cretaceous (earliest Puercan?) local fauna, Hell Creek Formation, southeastern Montana1
- New examples of Tyrannosaurus rex from the Lance Formation of Wyoming, United States1
- Fossil Vertebrate Collections1
Each of the 70 occurrences read was entered from one of these publications, ordered by how many each accounts for. This is not a search for papers mentioning the name. 18 further references are not listed. Entries link to doi.org where the Paleobiology Database holds an identifier, and to its own record where it does not. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.
Media and terms
Media content3
Picture of Tyrannosaurus rex
- Source
- Wikipedia/Commons
- Credit
- ScottRobertAnselmo
- Licence
- CC BY-SA 3.0
- Commercial use
- the licence allows it
Laser scan
- Source
- MorphoSource
- Licence
- In Copyright
- Commercial use
- cannot be read from the licence given — check the record
- Specimen
- Tyrannosaurus rex · AMNH:FARB:5027
3D model
- Source
- Sketchfab
- Licence
- CC0 Public Domain
- Commercial use
- the licence allows it
The description on this site
- Licence
- CC BY-SA 4.0
This is what the site found, which is not the same as what exists.
Keep going
What may have been alongside itTyrannosaurus through timeFormations of the Late CretaceousThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Osborn 1905