Tyrannosaurus

Genus of large theropod dinosaur

Tyrannosaurus is a genus of coelurosaurian theropod dinosaur that lived during the late Cretaceous period, approximately 68 to 66 million years ago. The species Tyrannosaurus rex (rex meaning "king" in Latin), often colloquially referred to as T. rex, is one of the most well-represented of the large theropods. Tyrannosaurus was among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event.

Description

Mounted skeleton of Tyrannosaurus rex

Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to its large and powerful hind limbs, Tyrannosaurus forelimbs were short but unusually powerful for their size and had two clawed digits. The most complete specimen measures up to 12.3 meters (40 feet) in length, and it is estimated to have weighed between 8.4 and 14 metric tons.

Discovery and History

Manospondylus vertebrae, initially thought to be a separate genus

The first partial skeleton of Tyrannosaurus was discovered in 1902 by the famous fossil hunter Barnum Brown in the Hell Creek Formation of Montana. The genus was formally described by Henry Fairfield Osborn in 1905. Initially, several other genera, such as Manospondylus and Dynamosaurus, were thought to be distinct, but later research confirmed they were synonymous with Tyrannosaurus.

Paleobiology

Tyrannosaurus was a top predator in its ecosystem, preying on large herbivorous dinosaurs such as hadrosaurs and ceratopsians. Its powerful jaws and serrated teeth were capable of crushing bone, and it likely had a keen sense of smell, aiding in its role as a scavenger as well.

Specimens

Sue, one of the most complete Tyrannosaurus skeletons

Numerous specimens of Tyrannosaurus have been discovered, with notable examples including Sue, housed at the Field Museum of Natural History in Chicago, and Scotty, one of the largest known specimens. These specimens have provided significant insights into the biology and life history of Tyrannosaurus.

Growth and Development

Studies of Tyrannosaurus growth patterns suggest that it experienced a rapid growth spurt during adolescence, reaching full size in about 20 years. This rapid growth was followed by a plateau in size, with individuals living up to 30 years.

Related Pages

• Dinosaur
• Theropoda
• Cretaceous–Paleogene extinction event

Scotty, another large specimen of Tyrannosaurus

Gallery

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  Diagram showing various Tyrannosaurus specimens
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  Reconstructed Tyrannosaurus at Philmont
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  Comparison of Tyrannosaurus with other large theropods
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  Skull of Tyrannosaurus rex