“The Largest Raptor in the Rock Record”
Binomial Utahraptor ostrommaysi · YOO-tah-RAP-tor
Early Cretaceous - 135-125 Ma
IllustrationUtahraptor fossil records in Fossil Atlas are mapped as selected modern discovery locations, with 2 source-backed records currently shown. Utah, United States, especially Cedar Mountain Formation records in the current atlas. Key mapped formations in the current dataset include Cedar Mountain. These pins are fossil record locations, not a complete ancient habitat map.
Utahraptor was a large Early Cretaceous dromaeosaur from the Cedar Mountain Formation of Utah. Fossil Atlas maps selected discovery records and connects the page to regional fossil guides.
Drawn true to scale on a metre ruler.
Length
measured5.5 m · 18 ft
Largest known specimens
Height
measured1.8 m (6 ft)
Body mass
estimate500 kg · 1,100 lb
Typical adult
Top speed
estimate40 km/h · 25 mph
Modelled, debated
Utahraptor was the largest known dromaeosaur, considerably bigger than its more famous relatives Velociraptor and Deinonychus. Its sickle claws were proportionally massive, and at the body size Utahraptor reached, it could have targeted prey much larger than a smaller raptor could handle. Its discovery in 1991 preceded the release of Jurassic Park and provided a real animal close in size to the fictional raptors depicted in the film.
The sickle claw
Very large relative to body size, with the second-toe claw reaching around 24 centimetres. Used for gripping and pinning prey rather than slashing, based on the same functional analysis applied to smaller relatives.
Size
Estimates of 5-7 metres in length and up to 500 kilograms, making it capable of tackling large ornithopods or sauropod juveniles that smaller dromaeosaurs could not manage.
The bonebed
A Utahraptor bonebed in Utah, found in the early 2000s and still being excavated, contains multiple individuals and may represent a group caught in a mud trap. Results from this excavation are still being published.
Timing
Utahraptor was described in 1993, the same year Jurassic Park was released. The film depicted animals close in size to Utahraptor but labelled as Velociraptor. The real Velociraptor is much smaller.
Position of this animal’s known range across 252 million years of the Mesozoic and beyond.
135-125 million years ago
Utahraptor was far larger than Velociraptor.
Its Utah record provides a North American comparison point for Deinonychus and Velociraptor.
The name ties directly to Utah, making it strong for regional internal links.
James Kirkland's team found the first Utahraptor material in the Cedar Mountain Formation of Utah in 1991. Kirkland, Robert Gaston, and Donald Burge formally named it in 1993. Later fieldwork in the same area identified a bonebed that may contain dozens of individuals, though excavation is ongoing and full results have not yet been published.
Animals known from the same deposits and time as Utahraptor.
Sauropelta
A nodosaurid ankylosaur from the Cedar Mountain Formation, well-defended but potentially vulnerable at smaller sizes.
Gastonia
An ankylosaur from the Cedar Mountain Formation covered in lateral spikes, likely a difficult target even for Utahraptor.
Hippodraco
An iguanodontid ornithopod from the same formation, a plausible prey animal.
Other members of Dromaeosauridae.
Deinonychus
A slightly smaller and slightly later North American dromaeosaur from the same general region.
Velociraptor
A much smaller relative from Mongolia, the most famous member of the family.
Microraptor
A tiny four-winged relative from China, showing the extreme size range within the dromaeosaurid group.
Pins show selected fossil records for Utahraptor; use them as modern discovery evidence, not a complete range map. Modern fossil discovery map: pins show where selected fossil and specimen records were found today, not ancient Earth positions. What does this mean?
Specimen evidence
No open specimen media or embeddable model assets are available in the local enrichment data yet.
Utahraptor is represented here by selected fossil records from utah, united states, especially cedar mountain formation records in the current atlas. Fossil Atlas maps those records as modern discovery locations.
No. The map shows modern fossil discovery locations from selected records. Ancient habitat and paleogeographic reconstructions are separate questions.
The current Fossil Atlas records include Cedar Mountain. Formation coverage depends on the selected dataset and may not be complete.
Yes. Use the expedition card generator to turn the Utahraptor map and specimen profile into a shareable card.
Selected fossil records from PBDB and museum biodiversity aggregators. This is not a complete fossil count by country; source labels and confidence notes help distinguish canonical paleobiology records from specimen-media records.
Reconstruction images are labeled illustrations and do not represent fossil evidence. Size, speed, and bite-force figures are typical published estimates and remain subject to revision as new specimens are described.
Maps use curated PBDB, museum, and specimen-source records with visible caveats.
Pins show where fossils were found or reported today, not exact ancient habitat positions.
Artwork is labeled separately from specimen photos, maps, and source records.
Request desk
Request another dinosaur like Utahraptor, submit a correction, or tell us what would make this page useful as a printable card.
Tell us which dinosaur or fossil site to map next, flag a correction, suggest a new pin, or request a card pack. Hit the button to open a prefilled email. We read every one.
Email request