I strongly feel that dinosaurs and humans were alive at the same time.
In the Bible, Job 40:15-18 describes God talking to Job about a possible dinosaur:
"Look at the behemoth,which I made along with you and which feeds on grass like an ox. What strength he has in his loins, what power in the muscles of his belly! His tail sways like a cedar; the sinews of his thighs are close-knit. His bones are tubes of bronze, his limbs like rods of iron."
Since this creature eats grass LIKE an ox, he must not be an ox, but he likely is a vegetarian. Verse 16 talks about the strength in his hips, so he could be an animal with powerful legs, such as an elephant. Verse 16 also says that he has a strong and massive stomach, so he could even be a hippo. But then verse 17 writes that "his tail sways like a cedar." Cedar trees are HUGE...so it can't be an elephant or a hippo. But what about a dinosaur, say a Brontosaurus?
Job 41:1-34 (look it up!) describes yet another beast--another possible dinosaur.
In history, Alexander The Great reported that, when he conquered parts of what is now India in 326 B.C. his soldiers were scared by great dragons that lived in caves; Marco Polo visited China in 1271 A.D. and reported that the emperor raised dragons to pull his chariots in parades (http://www.truthandscience.net/whataboutdinosaurs.htm).
In 1977, a Japanese crew of fishermen caught a dead creature that was about 30 feet long, with a neck about five feet long, and weighing about 4,000 pounds. It appeared to be a dinosaur known as the plesiosaur (Petersen, "Unlocking the Mysteries of Creation").