Dinosaur

Dinosaur were group of reptiles that lived on earth for over 160 millon years. They became extinct about 65 millon years ago. The dinosuars evolved 255 millons years ago during a geological period known as the Trassic. Some were only the size of a chicken, others were the biggest land animals that ever existed.

The same dinosuars did not exist throughout the age of reptilces. For example, Diplodocus lived during the jurassic and was a sauroped or lizard- footed dinosaur. Scientist have found evidence of over 500 types of dinosaur, spanning all the periods but it is believed that as many as 1,300 types may be existed and most of which are still not discoveres yet.

The Theropods were meat- eaters, all built to the same design. They has long mouths full of meat- tearing teeth, they walked on thier hind legs and had small bodies which they balanced with long, heavy tails. Some such as compsognathus, were chicken sized while the biggest were 12- m long killers, such as Tyrannosaurs.

Sauropods were plants- eaters. They had big, heavy bodies and moved around on all fours, using their long necks to reach leaves on trees. They were the biggest land animals that ever lived included Diplodocus and Brachiosaurs.