Name:
Utahraptor
(Utah's hunter).
Phonetic: You-tah-rap-tor.
Named By: James Kirkland, Robert Gaston, &
Donald Burge - 1993.
Classification: Chordata, Reptilia, Dinosauria,
Saurischia, Theropoda, Dromaeosauridae Eudromaeosauria, Dromaeosaurinae.
Species: U. ostrommaysi (type).
Type: Carnivore.
Size: Estimated between 5.5 to 7 meters long.
Known locations: USA, Utah - Cedar Mountain
Formation [Yellow Cat Member].
Time period: Barremian of the Cretaceous.
Fossil representation: Numerous specimens of
fragmentary remains.
Superficially,
Utahraptor appears to be an earlier, scaled up
version of Deinonychus.
Specimens of Utahraptor are fragmentary but suggest
a potential size of
up to seven meters long, with some more conservative estimates falling
nearer six meters long. These estimates make Utahraptor
a contender for
one of the largest known dromaeosaurid
dinosaurs, but if that were not
enough
there are some specimens that hint to Utahraptor
possibly being even
larger.
Being
a larger animal, Utahraptor also had a larger claw
estimated to
potentially be twenty-four centimetres long. Utahraptor
had thick leg
bones and are not what you would expect from a fast hunter. They may
have instead had extra powerful muscles for driving the killing claw
forwards into its prey. Bringing all of the above together, Utahraptor
probably focused upon its attentions to larger prey items such as
hadrosaurs or smaller sauropods.
As
a dromaeosaurid, Utahraptor probably shared the
same phylogenetic
features of the group, including having feathers. While no feathers
have been found with Utahraptor remains, it would
be an exception to
the 'group rule' if it did not have them. One thing to consider however
is that the large size of Utahraptor may have meant
it had a degree of
gigantothermy that would not have been present in its smaller group
relatives. If so then it may have had a reduced or altered arrangement
of feathers instead.
Further reading
- A large dromaeosaur (Theropoda) from the Lower Cretaceous of eastern
Utah. - Hunteria 2(10):1-16. - J. I. Kirkland, D. Burge & R.
Gaston - 1993.
- New osteological data and the affinities of Utahraptor
from the Cedar
Mountain Fm. (Early Cretaceous) of Utah. - Journal of Vertebrate
Paleontology. 21 (3): 36A. - B. B. Britt, D. J. Chure, K. L. Stadtman,
J. H. Madsen, R. D. Scheetz & D. L. Burge - 2001.
- A method for distinguishing dromaeosaurid manual unguals from pedal
"sickle claws". - Bulletin of the Gunma Museum of Natural History (11):
1–6. - P. Sewnter - 2007.
- Commentaries on different uses of the specific epithet of the large
dromaeosaurid Utahraptor Kirkland et al., 1993
(Dinosauria, Theropoda).
- The Bulletin of Zoological Nomenclature. 76 (1): 90−96. - T. V. V.
Costa & D. Normand - 2019.