Wouldn't it make sense that the ambush behavior that many crotalid species employ would force such an evolutionary path in areas where larger animals (with big feet!) may wonder? Assuming of course that these ancient snakes already vibrated their tails when nervous.
Theses snakes were probably cryptic ambush predators like the crotalus of today. If a snake hunts mainly by ambush it would have to be exposed along game trails where larger predators would frequent. Also, the snakes' small warm blooded prey (rabbits, larger rodents) probably foraged on the same vegatation that larger herbivorous animals ate. These factors would bring these larger animals into close proximity with early crotalus animals. The ambush theroy makes sense because these aniamls already had heat sensing pits, which is probably the best tool for hunting warm blooded prey by way of ambush.
If the evolution of a rattle was for use as a tool to distract predators from the snake's head, it would seem the rattle would not be so fragile and probably more conspicous like those of the ringneck snakes. If the rattle was used as a tool for attraction of prey, id love to find the cool type of insect that shakes and buzzes like that of a rattle, wouldn't it make more sense to evolve a tail looking like a worm? And I don't think insect hunting animals hunt by sound, they are more often attracted by insect-type movement (wrigling, crawling, ect- not shaking or vibrating).
What do you guys think of these ideas- my two pennies, thats all-
