Emerged naturally in a population of pigs, or was cultivated in a lab and released into pigs as a "trial" run?
"Scientists say the virus was first discovered in pigs in China in 2012 but it was not associated with disease. It was first detected in the United States in 2014 during a diarrhea outbreak in Ohio pigs and has since been detected in other countries, as well."
"Saif says for now, porcine deltacoronavirus has only affected human cell cultures in a laboratory setting – no actual people got sick. The virus was also able to bind to receptors in cells from cats and chickens."
https://www.cbsnews.com/news/deadly-new-pig-virus-porcine-deltacoronavirus-could-pose-threat-to-humans-researchers-say/?ftag=CNM-00-10aab7e&linkId=51757201