both are mammals, He may have made one earlier that had this feature and one went to the caves and one went to the water

also, you may have heard of Rupert Sheldrake's Morphogenetic Fields theory... Could be this was all designed in so this "convergence" was likely to happen to similar creatures both in the dark

there is too much evidence of genetic variation and speciation to say that sometimes there isn't hard forks as one species turns into two, but to say that God couldn't have made it that way deliberately is kinda silly