Yi

Yi is a genus of scansoriopterygid dinosaurs from the Late Jurassic of China. Its only species, Yi qi (Mandarin pronunciation: [î tɕʰǐ]; from Chinese: 翼; pinyin: yì; literally: "wing" and 奇; qí; "strange"), is known from a single fossil specimen of an adult individual found in Middle or Late Jurassic of Hebei, China, approximately 160 million years ago. It was a small, possibly tree-dwelling (arboreal) animal. Like other scansoriopterygids, Yi possessed an unusual, elongated third finger, that appears to have helped to support a membranous gliding plane made of skin. The planes of Yi qi were also supported by a long, bony strut attached to the wrist. This modified wrist bone and membrane-based plane is unique among all known dinosaurs, and might have resulted in wings similar in appearance to those of bats.