National Geographic : 2011 Feb
? X Basal archosaurs Crocs Pterosaurs DINOSAURS FAMILY TREE OF ARCHOSAURS Until recently, feathers had been found only on birds and closely related thero- pod dinosaurs, ranging from pigeon-size Epidexipteryx to seven-foot-long Beipiaosaurus. The discovery of featherlike structures on ornithischians---beaked dinosaurs far removed from birds---hints that the ancestor of all dinosaurs may have had feathers. "Fuzz" on pterosaurs suggests that protofeathers may have evolved even earlier, in the common ancestor of pterosaurs and dinosaurs. BEASTS OF A FEATHER ARTIST'S CONCEPT OF TIANYULONG MALE ON LEFT, FEMALE ON RIGHT Males of Tianyulong, a dinosaur only distantly related to birds, may have used filaments blooming from their backs to attract females, just as many male birds use their feathers today.