This is a color morph of fish that are probably some combination of various Xiphophorus ancestors. That means there is no scientific name, such as a species name, for them. The name they are given by the fish trade is intended to inspire people to buy them. I was at a fish auction today and had some creamsicle mollies for sale. I saw some almost identical mollies offered by someone else who was calling their fish lyre tailed gold dust mollies. My own have a pronounced lyre shaped tail, a partial sail fin and of course are a golden color. I was using the traditional pet shop name for mine and the other seller had decided it was not exciting enough. These color morphs change names as often as many Hollywood personalities change spouses.
If you are enjoying your fish, don't worry too much what the aquarium trade has decided to call them this week. Next week it will be something different anyway.