If the earth was only 6000 years old, man would have walked with the dinosaurs and it would have been recorded in the bible.
Behold now, Behemoth, which I made as well as you;
He eats grass like an ox.
Behold now, his strength in his loins
And his power in the muscles of his belly.
He bends his tail like a cedar;
The sinews of his thighs are knit together.
His bones are tubes of bronze;
His limbs are like bars of iron.
He is the first of the ways of God;
Let his maker bring near his sword.
- Job 40:15-19
And it is. You should read the Bible some time; its amazing what you'll find. There is as much about dynos as there is about any of the wild creatures. Interaction with wild animals has always been very limited.