Dino Index

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Latin Name Tyrannosaurus rex
Everyday Name T rex
Length 14 meters
Height 4 meters
Weight 7000 Kilog
Diet carnivore
Period Cretaceous
Pronunciation tie - ran - o - sor - us

Tyrannosaurus rex

T rex is maybe the most famous dinosaur today, so it is a natural place to start learning about dinosaurs. And besides, T rex was one of the largest carnivorous dinosaurs, and also one of the largest land carivores ever (but prehaps not the largest... Cacharodontosaurus and Giganotosaurus may be larger!!), so that can capture the imagination easily.

Tyrannosaurus rex captured my imagination as the king of dinosaurs when I was very young. We did not know about the less famous but perhaps larger Cacharodontosaurus and Giganotosaurus so king was the best name and seemed appropriate.

Now that name seems a bit wrong (see side box) but it is there to stay.

What did they eat?

Tyrannosaurus rex looks like a meat eater - a carnivore. The teeth are large and sharp and curve inward, so animals cannot escape after they are bitten.

But now, some scientists think Tyrannosaurus rex was actually a scavenger. They say that T. rex could not actually run fast enough to catch most dinosaurs. Although we don't know exactly how fast they were, most estimates are around Also, the front arms on T rex are too short to be really useful catching prey.

But other scientists point out that the whole body is built for attack - with a strong skull and sturdy bones. They also had large olfactory bulbs - those are the places inside the head that help it smell very well. So they probably hunted partly by smelling. They also had great binocular vision, which is neccessary when they are chasing prey.

Now, most scientists agree that T rex was a hunter but also scavenged when there was food available.

Tyrannosaurus rex has been found in several locations in North America, and also in Mogolia (sort of a cousin of the North American T rex).

Tyrannosauriods have been found across North America and Asia even from the late Jurassic period, but T rex itself was only present in the end of the cretaceous in North America.

Small Arms

Paleontologists have been puzzled for a long time about the small size of the arms. They were powerful, but too small to hold prey and at the same time bite it, so they may not have been used for attacking. There are only two claws at the end of these arms, so they don't appear very good for gripping things, either.