Earlier quoted context omitted.
The immediate source - palm civets at a local market was found almost as soon as they looked, about four months after the outbreak. Tracing back where they got it from took longer.
After the discovery of WIV1 in bats it was found that it efficiently infected human airway epithelial cells, and since the palm civets were never linked to any outbreaks it is possible that the virus had directly hopped to humans from bats and that the palm civets were unnecessary as an intermediate species. It was also later found that it infects racoon dogs, ferret badgers and domestic cats. There was never any con…
1. The closest known animal viruses to human SARS-1 were found in civet cats in 2003, within about a year of the first discovery of the virus in humans.
2. No animal viruses closer to SARS-1 have since been discovered. Dr. Shi discovered various viruses in bats that we believe are ancestral to SARS-1, including WIV-1 in 2013. This is significant because we believe SARS-1 evolved primarily in bats, but those viruses have lower genetic identity with SARS-1 than does the virus found in the civets.
If you disagree, please link a paper.
Based on the above, I don't understand why you'd think 2013 is the important date. Within about a year of the emergence of both of the previous two novel coronaviruses in humans (SARS-1 and MERS), a near-identical virus was discovered in animals (civets and camels). This is suggestive but not conclusive evidence that those animals first infected humans, and strong evidence that those viruses existed in nature--somewhere, even if not exclusively in those animals--before they emerged in humans.
For SARS-CoV-2, no such evidence has yet been found. This doesn't prove that SARS-CoV-2 is of unnatural origin, and I assume you'll mention the uncertainty in Ebola's zoonotic hosts shortly; but I don't see how anyone could treat that as irrelevant, except out of willful blindness.