Phytosaurus (meaning "plant lizard") is a dubious genus of extinct parasuchid phytosaur[1] found in an outcrop of the Keuper (likely the Exter Formation)[2] in Germany.

[3] In 1826, the holotypes of both species were discovered in Wurttemburg, Germany at the "Neckar" site at the base of the hill which Wildenau Castle stands upon.

[3] The holotype of P. cylindricodon consists of parts of the skull and jaws, with natural casts of the teeth which, however, did not preserve their conical form but were flattened which led to the misunderstanding they were specialised in eating plant material,[3] and the holotype of P. cubicodon consists of fragments of the jaw.

[4] Many later authors, beginning with Owen (1841), have classified both species of Phytosaurus as nomen dubia due to the lack of known diagnostic material.

[1] Owen (1841) had Phytosaurus classified as a synonym of Mastodonsaurus, an unrelated amphibian, and later Labyrinthodon, a now obsolete taxon.