Elvis came first and raped the beatles.
Elvis just copied black bluesmen on Beale Street. The same street his clothing supplier, Lansky Bros., was located. I'm not positive, but I think Lansky's is now known as BB Kings Blues Club.
Elvis used to watch guys like Big Boy Crudup, Pee Wee Crayton, BB King, T-Bone Walker, and numerous others in addition to the guys like Frank Sinatra and the balladeers he also copied.
So, The Beatles idolized the King, and they were contemporary artists alongside the Stones, but of the aforementioned, neither of them "invented" rock and roll.
Sam Phillips, though he never admitted to it, I'm sure he was paraphrased as saying "if I could just find a white man that sang like a negro, I would make a million dollars." Well, he was correct. And Elvis was his man that proved him to be correct.