Ilyodon is a genus of splitfins found in the Pacific slope river basins of Balsas, Tuxpan (Coahuayana), Purificación, Chacala (Marabasco), Armería and Ameca in western Mexico.
There are currently five recognized species in this genus according to FishBase, but only I. furcidens and I. whitei are indisputably valid (the remaining are then considered variants of those two).[1]