The Procolophonomorpha are an order or clade of early reptiles that appeared during the Middle Permian. They constitute a diverse asemblage that includes a number of lizard-like forms, as well as more diverse types like the Pareiasaurs. The most important subclade, the Procolophonia are traditionally thought to be ancestral to (and henxce to include) the Turtles. Lee 1995, 1996, 1997 argues that turtles evolved from Pareiasaurs but this view is by no means held unanimously. Rieppel and deBraga 1996 and deBraga & Rieppel, 1997 argue that turtles evolved from Sauropterygians Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... A clade is a term belonging to the discipline of cladistics. ... Orders See text. ... Families Procolophonoidea Owenettidae Procolophonidae ?Sclerosauridae Pareiasauroidea ?Rhipaeosauridae Pareiasauridae The Procolophonia are an suborder of herbivorous reptiles that lived from the Middle Permian till the end of the Triassic period. ... An order of Reptiles, called the Crown Group. Its distinctive characteristic is that part of its vertebrae, ribs, and sternum unite with its dermal plates so as to form a firm shell. ... Groups ?Placodontia Pachypleurosauridae Nothosauridae    Plesiosauria Sauropterygia (lizard flippers) is a group of very successful aquatic reptiles that flourished during the Age of the Dinosaurs before they became extinct. ...

Taxonomy

The following is based cheifly on Mikko's Phylogeny Archive, but also on Carroll 1988 and Laurin & Gauthier 1996. Note that classifications and even terminology vary widely, according to which authority one cites.

• CLASS SAUROPSIDA
  • Subclass PARAREPTILIA
    • Order Procolophonomorpha sensu Lee, 1995 (= Ankyramorpha deBraga & Reitz, 1996)
      • Superfamily Lanthanosuchoidea
        • Family Acleistorhinidae
        • Family Lanthanosuchidae
      • Order Procolophonomorpha sensu Rieppel & deBraga, 1996 and deBraga & Rieppel, 1997 = Suborder Procolophonia sensu Carroll 1988
        • Family Nycteroleteridae (paraphyletic)
        • Family Rhipaeosauridae) (paraphyletic)
          • Suborder Procolophonia sensu Laurin & Gauthier, 1996 = Procolophoniformes sensu Lee, 1995, 1996
            • Superfamily Procolophonoidea
              • Family Owenettidae (paraphyletic)
                • Family Procolophonidae
                • Family Sclerosauridae
            • Superfamily Pareiasauroidea (paraphyletic according to Lee 1995, 1996, 1997)
              • Pareiasauridae
            • Order Chelonia

Superclasses Anapsida Eurapsida Diapsida Reptilia was an old kingdom or phylum classification that has since been divided into 4 classes. ... Groups See cladograms below Parareptilia (at the side of reptiles) is a subclass or clade of Reptiles which are variously defined as an extinct group of primitive anapsids, or a more cladistically correct alternative to Anapsida. ... Families Procolophonoidea Owenettidae Procolophonidae ?Sclerosauridae Pareiasauroidea ?Rhipaeosauridae Pareiasauridae The Procolophonia are an suborder of herbivorous reptiles that lived from the Middle Permian till the end of the Triassic period. ... Families Procolophonoidea Owenettidae Procolophonidae ?Sclerosauridae Pareiasauroidea ?Rhipaeosauridae Pareiasauridae The Procolophonia are an suborder of herbivorous reptiles that lived from the Middle Permian till the end of the Triassic period. ... Genera Bradysaurus Nochelesaurus Embrithosaurus Deltavjatia Velosauria Shihtienfenia Pareiasuchus Pareiasaurus Scutosaurus Elginia Nanopareia Anthodon The Pareiasaurs - family Pareiasauridae - are a group of medium-sized to very large (60 cm to 3 meters long), stocky, early, reptilian herbivores, that flourished during the Permian period. ... Genera Bradysaurus Nochelesaurus Embrithosaurus Deltavjatia Velosauria Shihtienfenia Pareiasuchus Pareiasaurus Scutosaurus Elginia Nanopareia Anthodon The Pareiasaurs - family Pareiasauridae - are a group of medium-sized to very large (60 cm to 3 meters long), stocky, early, reptilian herbivores, that flourished during the Permian period. ... An order of Reptiles, called the Crown Group. Its distinctive characteristic is that part of its vertebrae, ribs, and sternum unite with its dermal plates so as to form a firm shell. ...

References

• Carroll, R. L., 1988: Appendix; Vertebrate Classification. in Carroll, R. L. 1988: Vertebrate Paleontology and Evolution, W. H. Freeman and company, New York
• deBraga M. & O. Rieppel. 1997. Reptile phylogeny and the interrelationships of turtles. Zoological Journal of the Linnean Society 120: 281-354.
• deBraga, M. & Reisz, R. R., 1996: The Early Permian reptile Acleistorhinus pteroticus and its phylogenetic position. Journal of Vertebrate Paleontology: Vol. 16, #3, pp. 384-395
• Laurin, M., & Gauthier, J. A., 1996 Phylogeny and Classification of Amniotes, at the Tree of Life Web Project
• Lee, M. S. Y. 1995. Historical burden in systematics and the interrelationships of 'Parareptiles'. Biological Reviews of the Cambridge Philosophical Society 70: 459-547.
• Lee M. S. Y. 1996. Correlated progression and the origin of turtles. Nature 379: 812-815.
• Lee, M. S. Y., 1997: Pareiasaur phylogeny and the origin of turtles. Zoological Journal of the Linnean Society: Vol. 120, pp. 197-280
• Rieppel O. & M. deBraga. 1996. Turtles as diapsid reptiles. Nature 384: 453-455.

Vertebrate Paleontology and Evolution is an advanced textbook on vertebrate paleontology by Robert L. Carroll, published by WH Freeman. ... The Tree of Life Web Project is an ongoing Internet project and providing information about the diversity and phylogeny of life on Earth. ...

Links

• Procolophonomorpha - Mikko's Phylogeny Archive
• Basal Anapsids - Palaeos