South America's Oldest Monkey (IMAGE) Natural History Museum of Los Angeles County Caption This is an artist rendering of what South America's oldest known monkey might have looked like. It was about the size of a squirrel, but with a longer tail, and probably weighed less than 250 grams (~0.5 lbs). Credit Artist: Jorge González Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.