The Gaur is a large, dark-coated ox of South Asia andSoutheast Asia. The biggest populations are found today in India. It is also called seladang or in context with safari tourisms Indian bison, which is technically incorrect. The gaur is the largest of all wild cattle, bigger even than the Asian Water Buffalo wild and Bison. The domesticated form of the gaur is called gayal or mithun.
- Bos gaurus laosiensis (Myanmar to China), the South-east Asian gaur, sometimes also known as Bos gaurus readei. This is the most endangered gaur subspecies. Nowadays, it is found mainly in Indochina and Thailand. The population in Myanmar has been wiped out almost entirely. Southeast Asian gaurs are now found mainly in small populations in scattered forests in the region. Many of these populations are too small to be genetically viable; moreover, they are isolated from each other due to habitat fragmentation. Together with illegal poaching, this will likely put an end to this subspecies in the not so distant future. Currently the last strongholds of these giants, which contain viable populations for long-term survival are Xishuangbanna National Nature Reserve in southern Yunnan, China, Cat Tien national park in VietNam, and Virachey national park in Cambodia. These forests, however, are under heavy pressure, suffering from the same poaching and illegal logging epidemic common in all other forests in South-east Asia.
- Bos gaurus gaurus (India, Nepal) also called "Indian bison". This is the most popular subspecies, containing more than 90 percent of the entire gaur population in the world.
- Bos gaurus hubbacki (Thailand, Malaysia). Found in southern Thailand and Malaysia peninsular, is the smallest subspecies of gaur.
- Bos gaurus frontalis, domestic gaur, probably a gaur-cattle hybrid breed
The wild group and the domesticated group are sometimes considered separate species, with the wild gaur called Bibos gauris or Bos gaurus, and the domesticated gayal or mithun (mithan) called Bos frontalis Lambert, 1804.
When wild Bos gaurus and the domestic Bos frontalis are considered to belong to the same species the older name Bos frontalis is used, according to the rules of the International Commission on Zoological Nomenclature (ICZN). However, in 2003, the ICZN "conserved the usage of 17 specific names based on wild species, which are pre-dated by or contemporary with those based on domestic forms", confirming Bos gaurus for the Gaur.Previously thought to be closer to bison, genetic analysis has found that they are closer to cattle with which they can produce fertile hybrids. They are thought to be most closely related to banteng and said to produce fertile hybrids