http://www.mariowiki.com/Super_Mario_FX
Super Mario FX is a game that was originally going to be released for the Super Nintendo Entertainment System, using the Super FX chip used in Super Mario World 2: Yoshi's Island. It seemed, however, that even the chip didn't have enough capability to run this complex 3-d platformer, so it was moved to the Nintendo 64, and released as Super Mario 64.
http://en.wikipedia.org/wiki/Super_Mario_FX#Development
Essentially what this means is that super mario 64 (But not 64) was originally going to be released on the SNES.