Hawksbill sea turtle, which is where "tortoiseshell" came from...pretty good reproduction of the real thing, actually.
I have a couple actual tortoiseshell picks, that were in the case my 1910 Gibson mandolin came in...extremely valuable, yet illegal to sell, and I won't use them, because I'm morally opposed to making things out of turtles and tortoises when there's no good reason to do so.
Like 'em better alive and swimming gracefully in the oceans or stomping around the yard.