Tyrannosaurus rex

A predatory Dinosaur. This is probably the most famous and most fearsome predator of all times. Tyrannosaurus rex (Cretaceous, 65 million years), it's name meaning 'terrible king lizard', is a very rare animal. Up until this day only 20 specimens are found, including only three complete skulls. This therapod? dinosaur was first found by [Barnum Brown]?, in the early 1900s.

Tyrannosaurus could reach a length of up to 14 metres (45 feet) and could weigh up to 5 tonnes. Like all other theropods, Tyrannosaurus had recurved teeth that ensured that meat was pulled free when biting their victims. All food was swallowed whole, since these dinosaurs never developed any chewing mechanism. Tyrannosaurus had only his teeth as a weapon (in contrast to for instance raptors, who also used their toe claws). The arms of Tyrannosaurus were exceptionally small, probably to make up for the weight of its enormous head.

Given the size of Tyrannosaurus, and combined with the fact that they were almost certainly warm-blooded, paleontologist? [James Farlow]? calculated the number of lawyers a grown Tyrannosaurus had to eat (based on a scene from the movie [Jurassic Park]?, in which a lawyer became T-Rex fodder) to stay alive. Taken an average weight of 68 kilograms, 292 lawyers would be needed to keep one T-Rex happy for a year!

The discussion about the feeding patterns of Tyrannosaurus rex, and other large predatory dinosaurs hasn't finished yet. Some paleontologists called these dinosaurs 'Land sharks', and portrayed them as highly active predators, while others see them as scavengers. The available evidence of bite marks in other animals and even other Tyrannosaurus, combined with the enormous serrated teeth and large jaw seem to speak in favour of a role as predator. Another theory is that their size and power allowed them to steal kills from smaller predators, much as modern-day lions often take the kills of hyenas and other smaller predators.

Although not much is known about the vision of Tyrannosaurus, the skulls clearly show that the eye sockets are positioned in such a way, that they had binocular vision.

In contrast to common belief, Tyrannosaurus Rex wasn't the only Tyrannosaurus around. The following species have been identified:

(measurements given are based on found fossils and estimates)

[Tyrannosaurus torosus]? (Russel, 1970)

• Skull length : 1.1 m.
• Total length : 9 m.
• Hip height : 2.5 m.
• Weight : 2.3 tonnes

[Tyrannosaurus bataar]? (Maleev, 1955)

• Skull length : 1.35 m.
• Total length : 10 m.
• Hip height : 2.9 m.
• Weight : 5 tonnes

Finally, Tyrannosaurus rex (Osborne, 1905)

• Skull length : 1.75 m.
• Total length : 13.6 m.
• Hip height : 4.4 m.
• Weight : 12 tonnes

The classification of these varies a little (for instance, T. battaar is sometimes called Tarbosaurus?).

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Tyranosaurus Rex was the original name of the 1970s pop group founded by [Marc Bolan]?, [T. Rex]?.

/Talk?