Aye-aye (IMAGE) North Carolina State University Caption The world's weirdest little primate has gotten even weirder, thanks to the discovery of a tiny extra digit. Aye-ayes possess small 'pseudothumbs' -- complete with their own fingerprints --- that may help them grip objects and branches as they move through trees. This is the first accessory digit ever found in a primate. Credit David Haring/Duke Lemur Center Usage Restrictions with credit 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.