When did the American buffalo disappear and become bison?

[muriel_volestrangler]

29. Yes, there are 4 species in this

Wikipedia says the African Cape buffalo (Syncerus) is not particularly related to the others, but it also has a reference to a 2009 paper on the genetics, which says that they are closer to the Asian water buffalo (Bubalus) than to the others (or to domestic cattle):

We identified 3 distinct lineages after the Bovini split from the Boselaphini and Tragelaphini tribes, which has lead to the (1) Buffalo clade (Bubalus and Syncerus species) and a more recent divergence leading to the (2) Banteng, Gaur and Mithan and (3) Domestic cattle clades. A fourth lineage may also exist that leads to Bison and Yak. However, there was some ambiguity as to whether this was a divergence from the Banteng/Gaur/Mithan or the Domestic cattle clade. From an analysis of approximately 30,000 sites that were amplified in all species 133 sites were identified with ambiguous inheritance, in that all trees implied more than one mutation at the same site. Closer examination of these sites has identified that they are the result of ancient polymorphisms that have subsequently undergone lineage sorting in the Bovini tribe, of which 53 have remained polymorphic since Bos and Bison species last shared a common ancestor with Bubalus between 5–8 million years ago (MYA).

http://www.biomedcentral.com/1471-2164/10/177/abstract

But, just to throw a spanner in the works, the Gaur is also called the Indian Bison.