Firstly, you won't find the word "dinosaur" in the bible because the name wasn't devised until Richard Owen coined it 1842. The term actually just means terrible lizzard.
Secondly, If you read the bible you'll see references to animals like dragons, scaley creatures, etc.
Thirdly, if you read the flood account you'll see that Noah was to bring two of every kind and assuming dinosaurs were around at the time it must include them. However, atheists like to assume that this must mean full adult sized creatures of every kind but the bible doesn't say that. Tiny dinosaurs were not huge but well, er... tiny!
Given these facts it's entirely possible that Noah took two of every creature on the ark!