The dinosaurs were a highly successful group of animals, who got their name from [Sir Richard Owen]
?, who proposed the name
Dinosauria, meaning 'fearfully great lizard'. Dinosaurs were descendents of Thecodonts and existed from the middle
Triassic to the end of
Cretaceous (210-220 to 65 million years ago). Birds are now generally believed to represent descendents of dinosaurs, and so are classed with them by those who believe groups should be monophyletic. Other than them, the last dinosaurs disappeared 65 million years ago, most likely caused by the effects a very large meteorite hitting the earth (a theory first proposed by [Walter Alvarez]
?).
Classification of dinosaurs
Dinosaurs are divided into two major groups, the Saurischia and the Ornithischia, on the basis of hip structure.
/Talk