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
Blue wildebeest placed in a separate genus, "Gorgon". In a study of the mitotic chromosomes and mtDNA, which was undertaken to understand more of the evolutionary relationships between the two species, the two were found to have a close phylogenetic relationship and had diverged about a million years ago. "C. taurinus" has five subspecies: The blue wildebeest is known to hybridise with the black wildebeest. The differences in social behaviour and habitats have historically prevented interspecific hybridisation, but it may occur when both species are confined within the same area, and the offspring are usually fertile. A study of these hybrid animals