藏羚羊
In 1945, American paleontologist George Gaylord Simpson classified both in the tribe Saigini under the same subfamily, Caprinae. Subsequent authors were not certain about the relationship between the two, until phylogenetic studies in the 1990s revealed that though morphologically similar, the Tibetan antelope is closer to the Caprinae while the saiga is closer to the Antilopinae.