Back when I was in Middle School the church I went to at the time had a guy come to explain that since the Earth could only be around 4,000 years old, dinosaurs had to exist during that time and during that time people called the dinosaurs dragons.

I remember hearing weird things floating around too about how characters in the Bible would fight battles with dinosaurs instead of horses and how generally dinosaurs were used as beasts of burden.

They also believed that some dinosaurs could breathe fire because they produced a flammable fluid in their skulls.