Aye-Aye's Hidden Thumb

                                                                                                                           Image: © David Haring/Duke Lemur Center

There's a little extra thumb-thing on the hand of the aye-aye, a strange-looking nocturnal lemur native to Madagascar. Tucked near each wrist is a small nub of bone and cartilage that's like a miniature thumb — and until recently, scientists didn't know this pseudothumb existed. --- LiveScience