1868,Charles Darwin,The Variation of Animals and Plants Under Domestication, Vol. I.[1]:
Besides these three species and the zebu, the yak, the gayal, and thearni (not to mention the buffalo or genusBubalus) have been domesticated; making altogether seven species ofBos.
1904, Arthur Erwin Brown, “The Zoology of North American Big Game”, inAmerican Big Game in Its Haunts[2]: