Procolophonomorpha is an order or clade containing most

parareptile Parareptilia ("at the side of reptiles") is a subclass or clade of basal sauropsids (reptiles), typically considered the sister taxon to Eureptilia (the group that likely contains all living reptiles and birds). Parareptiles first arose near th ...

s. Many papers have applied various definitions to the name, though most of these definitions have since been considered synonymous with modern parareptile clades such as Ankyramorpha and

Procolophonia The Procolophonia are a suborder of herbivorous reptiles that lived from the Middle Permian till the end of the Triassic period. They were originally included as a suborder of the Cotylosauria (later renamed Captorhinida Carroll 1988) but are ...

. The current definition of Procolophonomorpha, as defined by Modesto, Scott, & Reisz (2009), is that of as a stem-based group containing ''

Procolophon ''Procolophon'' is a genus of lizard-like procolophonid parareptiles that first appeared in the Early Triassic (Induan) of South Africa, Brazil, and Antarctica. It persisted through the Permian–Triassic extinction event, but went extinct in ...

'' and all taxa more closely related to it than to ''

Milleretta ''Milleretta'' is an extinct genus of millerettid parareptile from the Late Permian of South Africa. Fossils have been found in the Balfour Formation.Ruta, M., Cisneros, JC., Liebrecht, T., Tsuji, L. A. and Müller, J. 2011Amniotes through major ...

''. It constitutes a diverse assemblage that includes a number of lizard-like forms, as well as more diverse types such as the

pareiasaurs Pareiasaurs (meaning "cheek lizards") are an extinct clade of large, herbivorous parareptiles. Members of the group were armoured with scutes which covered large areas of the body. They first appeared in southern Pangea during the Middle Permian ...

. Lee 1995, 1996, 1997 argues that turtles evolved from pareiasaurs, but this view is no longer considered likely. Rieppel and deBraga 1996 and deBraga and Rieppel, 1997 argue that turtles evolved from

sauropterygia Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria became ...

ns, and there is both molecular and fossil (''

Pappochelys ''Pappochelys'' ( meaning "grandfather turtle" in Greek) is an extinct genus of diapsid reptile possibly related to turtles. The genus contains only one species, ''Pappochelys rosinae'', from the Middle Triassic of Germany, which was named by pa ...

'') evidence for the origin of turtles among

diapsid Diapsids ("two arches") are a clade of sauropsids, distinguished from more primitive eureptiles by the presence of two holes, known as temporal fenestrae, in each side of their skulls. The group first appeared about three hundred million years a ...

reptiles.

Classification

The following

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

is simplified after the phylogenetic analysis of MacDougall and Reisz (2014) and shows the placement of Procolophonomorpha within

Parareptilia Parareptilia ("at the side of reptiles") is a subclass or clade of basal sauropsids (reptiles), typically considered the sister taxon to Eureptilia (the group that likely contains all living reptiles and birds). Parareptiles first arose near th ...

and its interrelationships. Relationships within bolded terminal clades are not shown.

References

* Carroll, R. L., 1988: Appendix; Vertebrate Classification. in Carroll, R. L. 1988: ''

Vertebrate Paleontology and Evolution ''Vertebrate Paleontology and Evolution'' is an advanced textbook on vertebrate paleontology by Robert L. Carroll, published in 1988 by WH Freeman. It provides a very detailed technical account of various groups of living and fossil vertebrate ...

'', W. H. Freeman and Company, New York * deBraga M. and O. Rieppel. 1997. "Reptile phylogeny and the interrelationships of turtles". ''Zoological Journal of the Linnean Society'' 120: 281–354. * deBraga, M. and 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., and Gauthier, J. A., 199
Phylogeny and Classification of Amniotes
at the

Tree of Life Web Project The Tree of Life Web Project is an Internet project providing information about the diversity and phylogeny of life on Earth. This collaborative peer reviewed project began in 1995, and is written by biologists from around the world. The site ...

* 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. and M. deBraga. 1996. "Turtles as diapsid reptiles". ''Nature'' 384: 453–455.

External links

Basal Anapsids
–

Palaeos Palaeos.com is a web site on biology, paleontology, phylogeny and geology and which covers the history of Earth. The site is well respected and has been used as a reference by professional paleontologists such as Michael J. Benton, the professor of ...

{{Taxonbar, from=Q3087256 Procolophonomorphs Prehistoric animal orders Guadalupian first appearances Late Triassic extinctions