Critterature: Bones of Contention

I'd like to step back in time a bit And mention the dinosaur. He lived two hundred million years And then was seen no more. The dino's demise is a mystery That's hashed and often rehashed here. One fav'rite hypothesis seems to be That a giant asteroid crashed here. Argued by clerics, and scientists, And other great men of distinction, Some clearly deluded, Yet none has concluded What actually caused the extinction. What really occurred Lies somewhere obscured Amongst all those theories and guesses. Some still do remain, though, Like the crane and komodo, And a number of interstate truck-stop waitresses.