Yep. Was watching a nature show the other day about mountain lions and the moderator said that "the mountain lion's mouth evolved to be a perfect fit for a deer's neck". This explains all the fossils of the extinct small-mouthed mountain lion, and the extinct large mouth mountain lion.(/sarcasm off)
Odd that the deer's neck didn't evolve to not fit the lion's mouth.
How would that have imparted a survival advantage for the deer?