Mimomys youhenicus was named by Xue (1981) ['All the inselfalte, prismenfalte and mimomyskante well developed. Enamel islet exists at about the same stage as the tooth has two large roots, the roots grew early. The fourth inner trianglar nearly opposite to the third outer trianglar, and the posterior side of the crown is rather flat and long.']. Its type specimen is not given. Its type locality is You-he, Lower River You, Weinan, Shensi, which is in a Piacenzian lacustrine horizon in China.