Answer:
the other guy is wrong, Snakes and lizards share a common ancestor, even though a snake's hind legs are buried somewhere in the muscle, lizards have 4 legs, So they share a common ancestor. Snakes and lizards also belong to the same species.
So, my best explanations for this question are that Snakes and lizards share a common ancestor, and they both belong to the same species, like I said in the first few sentences.
Snakes and lizards both have pelvic organs even though snakes don't have hind legs.
I hope this helps! :)