Bos mutus Przewalski, 1883 - Wild Yak

There are a few taxonomic disputes due to existence of a 'domesticated' variety/species of the same. While B. mutus is widely recognized as Wild Yak and B. grunniens as Domestic Yak, some authors consider B. mutus as subspcies of B. grunniens which is likely to be errenous and lacks enough support for the claim. 

Cervus elaphus Linnaeus, 1758 - Hangul (Kashmir Stag)

Kashmir Red Deer, Kashmir Stag or Hangul is a taxonomically disputed species. Some authors consider this species as a separate species i.e. Cervus hanglu whereas others consider it as a subspecies of Red Deer i.e. C. elaphus. There is another claim that considers this as a subspecies of Cervus canadensis. Nevertheless, there is no conclusion yet.