Global flood.
They were probably around after the flood,
but a whole bunch of yayhoos in armor, out to prove themselves by killing a “dragon”, exterminated them.
They would have survived on Noah's Ark.
Noah's flood is what I think it was. At the time Man took up only a small part of the planet. There was plenty left for Dinosaurs to roam, on continents yet to be touched by human footprints.
I’m one of those crazy conservative nut jobs that believes a lot of them died in the flood and the remainder were killed off as humans repopulated...what would give the most meat? Dinosaurs..one of God’s commandments after the flood was to eat them there hamburgers (meat..for the first time)...also If you believe in a literal Noah and Ark then noah certainly wouldn’t take the biggest dinos on board he’d take babies...and yes, there is evidence of dinosaur prints with human fossilized prints...and an obscure and often hidden story of a freshly mounted dinosaur in Italy in the 1560’s...but then again, I could just be a whacko