There are references to dinosaur like animals in Job 40 and 41 which are called Behemoth and Leviathan if I am not mistaken. They are said to be the first's of the ways of God, talking about creation I believe.

As Counts mentioned when it speaks of a day in the Bible, it doesn't necessarily mean a 24 hour day as we think of now. It also mentions in Genesis 1 that beasts were made before man, so with that context it is plausible to consider dinosaurs and their context to the Bible.