Before humans descended on the island of Madagascar there was a species of lemur as a big as gorilla. Today,the largest lemur weighs 20 lbs. (The smallest, the mouse lemur, and weighs 1.1 oz,and has "the smallest known brain of any primate, at just 2 grams, or " according to Wikipdia.). I'm not certain what kind of lemur this is,but it likes to have people scratch its back. (And this is not a video that should form you feel apt, says Barbara J. King, or an anthropology professor at the College of William and Mary.)
Source: boingboing.net