In the original concept art for the Cataclysm expansion, their mandibles differed from those of the common raptor, being somewhat similar to a beak. Also, their spikes appeared to be structures similar to feathers, due to their shape and location, meaning that these raptors might have been on their way to evolving into birds.
Though the majority of Raptor Rise is destroyed and under rivers of lava after Volcanoth!, the raptors can still be found by hunters wanting to tame them. They are on a small shelf[64.1, 60.5]