@chr It's like a portmanteau. Top half anthro + bottom half human (minotaur) combined with top half human + bottom half theriomorphic (centaur) equals top half anthro + bottom half therio.
Completely ignoring the fact that the -taur of centaur and the -taur of minotaur are completely different morphemes. (actually, I don't think the -taur of centaur is a morpheme at all)