wild ox vs aurochs

wild ox and aurochs both are nouns.

Word	Noun	Adjective	Verb	Adverb
wild ox	Yes	No	No	No
aurochs	Yes	No	No	No

As nouns, aurochs is a hyponym of wild ox; that is, aurochs is a word with a more specific, narrower meaning than wild ox:

wild ox: any of various wild bovines especially of the genera Bos or closely related Bibos
aurochs: large recently extinct long-horned European wild ox; considered one of the ancestors of domestic cattle

Other hyponyms of wild ox include Bos primigenius, urus, Bos grunniens, yak, banteng, banting, Bos banteng, tsine, Asian wild ox.

wild ox (noun)	aurochs (noun)
any of various wild bovines especially of the genera Bos or closely related Bibos	large recently extinct long-horned European wild ox; considered one of the ancestors of domestic cattle
	European bison having a smaller and higher head than the North American bison