Daspletosaurus

Daspletosaurus Temporal range: Late Cretaceous
Daspletosaurus skull at the Chicago Field Museum.
Conservation status
Fossil
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Superorder:	Dinosauria
Order:	Saurischia
Suborder:	Theropoda
Family:	Tyrannosauridae
Subfamily:	Tyrannosaurinae
Tribe:	Tyrannosaurini
Genus:	Daspletosaurus
Binomial name
Daspletosaurus torosus Russell, 1970

Daspletosaurus (IPA: /das'plitosɑrəs/; dahs-PLEE-toh-sawr-us) meaning 'frightful lizard', from the Greek daspleto-/δασπλητο- meaning 'horrid, frightful' and saurus/σαυρος meaning 'lizard', was a theropod dinosaur from the Late Cretaceous Period of what is now North America.

Discovery and species

The size of Daspletosaurus, compared with a 1.8 m (approx. 6 ft) human.

A contemporary of Gorgosaurus, Daspletosaurus was founded on a skeleton originally believed to be an undescribed species of Gorgosaurus. Currently, one species of Daspletosaurus, D. torosus, (torosus meaning 'brawny') has been officially recognized. However, a recent tyrannosaur find in Montana is thought to be that of a new (still un-named) daspletosaur species. The skull of this find seems to indicate a more Tyrannosaurus-like animal than D. torosus, possibly indicating an intermediate form between D. torosus and T. rex. Most of the specimens found were in Alberta and others were found in New Mexico.

Daspletosaurus species

• D. torosus

Classification

It has been suggested that Daspletosaurus is a direct ancestor of Tyrannosaurus. The massive, stocky build of the two tyrannosaurids and certain similarities in skull structures seem to be indicators of a close phylogenetic relationship between the two genera. Some have even gone further, to suggest that Daspletosaurus is actually a species of Tyrannosaurus (Tyrannosaurus torosus), but this has not been universally accepted.

Paleobiology

Describer Dale Russell hypothesized that while the more lightly built and more common Gorgosaurus may have specialised in preying on the more common species of hadrosaurids, the heavier, more robust Daspletosaurus may have specialised in the less prevalent armoured species of the time, such as the ceratopsids.

In popular culture

Daspletosaurus was the main character in an episode of the 4 part Discovery Channel special, Dinosaur Planet.

Data

• Weight: 3.6 tonnes (4 short tons)
• Length: 8.5 metres (28 feet)
• Found: Alberta, Canada; Montana, USA
• Period: Upper Cretaceous, Late Campanian
• Family: Tyrannosauridae

References

• Liddell & Scott (1980). Greek-English Lexicon, Abridged Edition. Oxford University Press, Oxford, UK. ISBN 0-19-910207-4.

• Dinosaur Walk Museum