I have recently had an epiphany about dinosaurs that makes perfect sense! You would have to be spiritual minded to see it so I suspect many scientific minded people will tell me I've lost it...that's okay.
Here was my idea, just as the fallen angels have manipulated with genetics to claim their own creations (and to piss God off), I suspect they took God's creation of birds and genetically altered them to make their own creation. That is why scientists claim dinosaurs evolved into birds because so much of the genetic code of birds is in them. They need a life form they can inhabit but God has designed a soul for each of his life forms that they cannot trump...for example, a foal is born and the spirit of a horse enters into it, a child is born and the spirit of a man enters into it; however, if you genetically combine the two and form a centaur, neither the spirit of a horse nor the spirit of a man will enter into it thus the fallen angel has its vessel. (Tom Horn explains this best but he doesn't take it to the "dinosaur level")
I believe they have been tampering with God's creation for so long. It began with dinosaurs (which God wiped out by some means...further evidence that He didn't create them), then the Nephilim (which God wiped out with Noah's flood) and now, I'm convinced, these "alien" abductions which seem to always have some sexual tampering attached to them, is the fallen angels, once more, taking God's creation and manipulating it's DNA genetically so they can make a near match and claim their own "creation" that they can inhabit. That's why people here talk about "shape-shifters" and hybrids. I believe they DO exist as an affront to God! We should expect His Divine Judgment to occur very soon, imo!