Chameleons, those shade-shifting, intricately camouflaged lizards that can change color in response to environmental or behavioral influences. Since the oldest lineages of chameleons are all from Madagascar, scientists believe they evolved on the island and spread out from there. As far as paleontologists can tell, the first chameleons evolved shortly after the extinction of dinosaurs 65 million years ago. Unlike other animals that change color, such as the squid and octopus, chameleons do not modify their hues by accumulating or dispersing pigments within their skin cells, the researchers found. Instead, the lizards rely on structural changes that affect how light reflects off their skin, the researchers said. Although chameleons are believed to have originated in Africa or Madagascar, the oldest known fossil, 26 million years old, is Chamaeleo caroliquarti from western Bohemia.
