Nyanzachoerus pattersoni is recognized as a subspecies of Nyanzachoerus kanamensis and defines the eastern rift forms of the Nyanzachoerus kanamensis. Nyanzachoerus is ancestral to its decendents Notochoerus. Nyanzachoerus is characterised by large and simple premolars, which in Nyanzachoerus are larger than those of Notochoerus.
Nyanyachoerus possess enlarged rear premolars relative to their anterior premolars. They are a sexually dimorphic species. Mandibles are deep and robust and they have relatively thick tooth enamel. Worn teeth have cusps that show dentine lakes that are star shaped.