Most research into the origins of the coronavirus acknowledges that it likely evolved from a strain found in horseshoe bats. The strain of the virus present in bats has been found to be almost 96% similar to the one found in humans. However, the virus in humans includes a key protein not present in the horseshoe bat variation, meaning either that there was an intermediate host before the virus jumped to humans or that the virus evolved within humans before becoming dangerous.
No specific animal coronavirus has yet been directly linked to the human version. Many possible routes involving both bats and other species remain under exploration.