Smallest reptile on earth discovered in Madagascar. The male version of the Brookesia nana, or nano-chameleon, has a body of just 13.5mm and is about the size of a sunflower seed. This makes it the smallest of about 11,500 known species of reptiles, according to the Bavarian State Collection of Zoology in Munich. Its length from top to tail is 22mm (0.86in) and is small enough to fit comfortably on a human fingertip.