Kuehneosaurus is an extinct genus of Late Triassic reptile from the United Kingdom. Measuring 72 centimetres long (2.3 feet), it had "wings" formed from ribs which jutted out from its body by as much as 14.3 cm, connected by a membrane which allowed it to slow its descent when jumping from trees. It is a member of a family of gliding reptiles, the Kuehneosauridae, within the larger group Lepidosauromorpha, which also contains modern lizards and tuatara.
Unlike its longer "winged" relative Kuehneosuchus (which may be a species of the same genus or represent a different sexual morph), aerodynamic studies have shown that Kuehneosaurus was probably not a glider, but instead used its elongated ribs to parachute from the trees. A study by Stein et al. in 2008 found that its parachuting speed, descending at a 45-degree angle, would be between 10 and 12 metres per second. Pitch was controlled by lappets (wattle-like flaps of skin) on the hyoid apparatus, as in the modern gliding lizard Draco.
