What two species were lumped together under the name A. leucophaeus?
Based on studies of morphology, the bluebuck has historically been classified as either a distinct species or as a subspecies of the roan antelope. After its extinction, some 19th-century naturalists began to doubt its validity as a species, with some believing the museum specimens to be small or immature roan antelopes, and both species were lumped together under the name A. leucophaeus by the English zoologist George Robert Gray in 1821. The Austrian zoologist Franz Friedrich Kohl pointed out the distinct features of the bluebuck in 1866, followed by Sclater and Thomas, who rejected the synonymy in 1899.In 1974 the American biologist Richard G. Klein showed (based on fossils) that the bluebuck and roan antelope occurred sympatrically on the coastal plain of the southwestern Cape from Oakhurst to Uniondale during the early Holocene, supporting their status as separate species. In 1996 an analysis of mitochondrial DNA extracted from the bluebuck specimen in Vienna showed that it is outside the clade containing the roan and sable antelopes. The study therefore concluded that the bluebuck is a distinct species, and not merely a subspecies of the roan antelope as was supposed. The cladogram below shows the position of the bluebuck among its relatives, following the 1996 analysis:
bluebuck roan antelope