Genomic sequencing  of a SARS-like virus suggests retlation to a virus that is known to infect bats. From NPR news:

Dutch virologists have just published the whole genome of the new coronavirus — all 30,118 letters of its code. And, the sequence reveals that the mystery virus is most closely related to coronaviruses that infect bats in Southeast Asia.

In fact, the pathogen is more similar to two bat viruses than it is to the human SARS virus that sent the world into a panic when it infected nearly 8,000 people in 2003.

Virologist Ron Fouchier, who has done controversial work on bird flu viruses, led the sequencing effort of the SARS-like virus. He tells Shots the results suggest that the new coronavirus virus came from bats. “Bats harbor many coronaviruses, so it’s logical to assume that bats are the natural reservoir” of the new pathogen, he says.

“But this doesn’t mean the Saudi man contracted the virus from bats,” says Fouchier.

When viruses jump from animals to humans, there’s usually a second animal that connects the natural carrier with humans. This species is called the amplifier because it increases the number of viral particles that can hop over into people.