Thats not something I was expecting to see. Very weird and cool at the same time.
I've seen that show too on discovery. And no the genes for legs and feet are infact still there believe it or not, they are just dormant or now serve a different use. On rare occassions the genes awaken and you can get weird animals liks this. For example theres dolphins with 4 flippers, chickens with teeth, people with tails, and apparently snakes with limbs.
It is also possible to awaken the genes artificially in a lab. For example in theory scientist could turn a chicken, turkey, emu, or any other bird into something that looks like a theropod dinosaur with arms, claws, scales, teeth, tail ect. Weather that'd be a good idea is another story all together.