Cow-bison hybrids (cattalo, beefalo) are also fertile.
Those are actually different genera as well (Bos taurus x Bison bison), not just species. As is the case with the wholphin (Pseudorca crassidens x Tursiops truncatus), which is why I believe the textbook definition of "species" is bullshit and needs to be dropped or at least revised.
Different human "races" are not different species, however, and in fact there is a lot more genetic diversity within different African populations than there is between African and non-African populations for one. While non-African populations do have tiny amounts of Neanderthal DNA mixed in due to interbreeding, there isn't anywhere enough to warrant a separate classification even at the subspecies level.