|Named By:||Eberhard Fraas in 1889|
|Time Period:||Late Triassic|
|Location:||England - Bromsgrove Sandstone Formation (Finstall Member). Germany - Hassberge Formation, Lowenstein Formation, Stuttgart Formation, Trossingen Formation. Greenland (Oersted Dal Member) - Fleming Fjord Formation. Luxembourg. Poland - Drawno Beds Formation. Russia - Bukobay Formation. Thailand - Huai Hin Lat Formation|
|Size:||Skulls up to 70 centimetres long, largest individuals up to 4.3 meters long|
|Classification:||| Chordata | Amphibia | Temnospondyli | Mastodonsauridae ||
|Also known as:||| Mastodonsaurus robustus ||
Cyclotosaurus is an extinct genus of temnospondyl within the family Mastodonsauridae. It was of great size for an amphibian, reaching 3-4.3 m (9.8-14.1 ft) in length with an elongated 70 cm (28 in) skull.