Black wildebeest the hybrid as compared to either of its parents. In some animals, the auditory bullae are highly deformed, and in others, the radius and ulna are fused. Black wildebeest are sexually dimorphic, with females being smaller in size and more slender than males. The head-and-body length is typically between . Males reach about at the shoulder, while females reach . Males typically weigh and females . A distinguishing feature in both sexes is the tail, which is long and similar to that of a horse. Its bright-white colour gives this animal the vernacular name of "white-tailed gnu", and also distinguishes
Black wildebeest in the 1800s. The black wildebeest is currently included in the same genus as the blue wildebeest ("Connochaetes taurinus"). This has not always been the case, and at one time the latter was placed under a separate genus of its own, "Gorgon". The black wildebeest lineage seems to have diverged from the blue wildebeest in the mid- to late Pleistocene, and became a distinct species around a million years ago. This evolution is quite recent on a geologic time scale. Features necessary for defending a territory, such as the horns and broad-based skull of the modern black wildebeest, have been