Lotosaurus is an extinct genus of rauisuchian archosaur that lived in China. It was 2.5 m (8 ft 4 in) long and a heavily built quadruped. It was a herbivore, biting off leaves with its toothless jaws. Lotosaurus, like other members of the family Ctenosauriscidae, had a sail on its back. It looked similar to that of Permian pelycosaurs like Dimetrodon and Edaphosaurus, although not as high. It may have been used for display and/or body temperature regulation.