The meaning of ‘dinosaur’

The name dinosaur is derived from two Greek words: deinos meaning ‘fearfully great’ and sauros meaning ‘lizard’. It was coined by the English anatomist Richard Owen in 1842. Owen recognized that the huge fossilized bones unearthed at several places in nineteenth-century England were markedly different from the bones of the other existing reptiles.

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How is an alligator different from a crocodile?

A crocodile has a ‘V’ shaped snout, whereas an alligator has a ‘U’ shaped snout. When a crocodile closes its mouth, the fourth tooth in the lower jaw sticks up outside the top jaw. However, there is a well-defined constriction in the upper jaw behind the nostrils to accommodate it. When an alligator does the same thing, the tooth is hidden. This is because, in the alligator, the upper jaw is longer than the lower jaw.

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