The Unique Wildlife of South America (Xenarthran) had time to evolve while South America was isolated from Africa about 110 million years ago when the Atlantic started to form , and isolated from Antarctica and South America about 35 million years ago. It did not reconnect with North America until the Isthmuth of Panama formed about 3 million years ago.
Marsupials like the Opossum , Xenarthrans like the Armadillos, Anteters and Sloths where the result
Monkeys rafted to South America from Africa about 40 million years ago.
Jaguars, Pumas, Spectacled Bears, and Camel relatives that became llamas all entered Via Isthmuth of Panama when it formed.