Jaguars south of the Amazon River

Before recent tests failed to establish that the jaguar was divided into different subspecies, it was presumed that different subspecies existed north and south of the Amazon River, such as Panthera onca onca north of the river, and Panthera onca palustris south of the river. Eventually, it was reckoned that geographical barriers, such as the Amazon River or the Andes Mountains, limited the flow of genes between jaguars, if not restricting them to be different subspecies. Southern jaguars disappeared in a number of places, like the Pampas' part of Argentina and Uruguay.