Pachypleurosauria

thumb|Life restoration of the pachypleurosaur [[Keichousaurus]] Pachypleurosauria is an extinct clade of primitive sauropterygian reptiles from the Triassic period. Pachypleurosaurs vaguely resembled aquatic lizards, with elongate forms ranging in size from , with small heads, long necks, paddle-like limbs, and long, deep tails. The limb girdles are greatly reduced, so it is unlikely these animals could move about on land. The widely spaced peg-like teeth project at the front of the jaws, indicating that these animals fed on fish. In the species Prosantosaurus, it was observed that they fed on

Keichousaurus (meaning "Kweichow lizard") is an extinct genus of pachypleurosaurian marine reptile from the Chialingchiang and Falang Formations of China with two known species attributed to the genus: K. hui and K. yuananensis.

Anarosaurus is an extinct genus of pachypleurosaurs that lived in the Middle Triassic period (Anisian) and has been found in the Jena Formation and the Karlstadt Formation of Germany and the Winterswijk Quarry (Lower Muschelkalk) of The Netherlands. Two species are known: A. pumilio (the type species) and A. heterodontus. The holotype of A. pumilio was originally housed at the Institut und Museum fur Geologie und Palaontologie, Georg-August-Universitat, Gottingen, but can no longer be located today because it was lost or destroyed during World War II. Anarosaurus was a small reptile with an es

Dianopachysaurus is an extinct genus of pachypleurosaur known from the lower Middle Triassic (Anisian age) of Yunnan Province, southwestern China. It was found in the Middle Triassic Lagerstätte of the Guanling Formation. It was first named by Jun Liu, Olivier Rieppel, Da-Yong Jiang, Jonathan C. Aitchison, Ryosuke Motani, Qi-Yue Zhang, Chang-Yong Zhou and Yuan-Yuan Sun in 2011 and the type species is Dianopachysaurus dingi, thanking a Professor Ding for his help.

Honghesaurus is an extinct genus of pachypleurosaur from the Anisian-age Guanling Formation of China. The type specimen measures about in total body length.

Serpianosaurus (meaning "Serpiano lizard") is an extinct genus of pachypleurosaurs known from the Middle Triassic (late Anisian and early Ladinian stages) deposits of Switzerland and Germany. It was a small reptile, with the type specimen of S. mirigiolensis measuring long.