Ferinestrix vorax is an extinct mustelid carnivoran of enigmatic relationships, known from a partial mandible and femur collected from the 3.2- and 3.6-Myr-old deposits of Hagerman Fossil Beds National Monument, Idaho, USA. Here, we report Ferinestrix rapax sp. nov. based on 80 remains of skull and dentition from a 3.1–3.6-Myr-old deposit of Udunga, Transbaikal, Russia. We demonstrate that Ferinestrix is a stem genus of the badger subfamily Melinae. This genus is distinctly larger and more carnivorous than any other total-clade meline. We show that Ferinestrix originated in Asia and immigrated to North America no later than at the early (Zanclean) to late (Piacenzian) Pliocene transition, and that the North American F. vorax and Asian F. rapax underwent parallel evolution toward increased carnivory. © 2013 The Linnean Society of London, Zoological Journal of the Linnean Society, 2013, 167, 208–226.