Parareptilia 5162226 220102249 2008-06-18T08:22:33Z 190.95.27.232 {{Taxobox | name = Parareptilia | fossil_range = [[Permian]] to [[Triassic]] (without Chelonia); or Permian to Recent (if incl. Chelonia) | image = Nyctiphruretus BW.jpg | image_caption = ''[[Nyctiphruretus]]'' | regnum = [[Animal]]ia | phylum = [[Chordate|Chordata]] | subphylum = [[Vertebrate|Vertebrata]] | superclassis = [[Tetrapoda]] | classis = [[Reptile|Sauropsida]] | subclassis = '''Parareptilia''' | subclassis_authority = [[Everett C. Olson|Olson]], [[1947]] | subdivision_ranks = Groups | subdivision = 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]]. Whether the term is valid depends a lot on the phylogenetic position of turtles, the relationships of which to other reptilian groups are still uncertain The name Parareptilia was coined by [[Everett C. Olson|Olson]] 1947 to refer to an extinct group of Paleozoic reptiles, as opposed to the rest of the reptiles or [[Eureptilia]] ("true reptiles"). The name fell into disuse, until it was revived by [[cladistics|cladistic]] studies, to refer to anapsida that were thought unrelated to turtles. [[Jacques Gauthier|Gauthier]] ''et al.'' 1988 provided the first [[phylogeny|phylogenetic]] definitions for the names of many amniote taxa, including [[Sauropsida]] as the parent clade for [[Reptilia]], and argued cladistically that captorhinids and turtles were sister groups, constituting the clade Anapsida (in a much more limited context than the definition given by [[Alfred Sherwood Romer|Romer]] 1967). A name had to be found for various [[Permian]] and [[Triassic]] reptiles no longer included in the Anapsids, and "Parareptiles" was chosen. However, they did not feel confident enough to erect Parareptilia as a formal taxon. Their [[cladogram]] was as follows: --o [[AMNIOTA]] |-- [[Synapsida]] `--o [[Sauropsida]] |--o "[[parareptiles]]" | |-- [[Mesosauridae]] | `--+-- [[Procolophonidae]] | `--+-- [[Millerettidae]] | `-- [[Pareiasauria]] `--o [[Reptilia]] |---o [[Anapsida]] | |-- [[Captorhinidae]] | `-- [[Testudines]] `--o [[Romeriida]] |-- [[Protorothyrididae]] `-- [[Diapsida]] [[Michel Laurin|Laurin]] and [[Robert Reisz|Reisz]] 1995 presented a different cladogram, in which the Reptilia are divided into Parareptilia (now a formal taxon) and Eureptilia. The Captorhinidae are transferred to the Eureptilia, and the Parareptilia includes both early Anapsid reptiles and turtles, but not the Captorhinidae and Protorothyrididae. The mesosaurs are placed outside both groups, as the sister taxon to the reptiles (but still sauropsids). The traditional taxon of Anapsida is rejected as paraphyletic. This gives the following: --o AMNIOTA |-- Synapsida `--o Sauropsida |-- Mesosauridae `--o Reptilia |--o Parareptilia | |-- Millerettidae | `--+-- Pareiasauria | `--+-- Procolophonidae | `-- Testudines `--o Eureptilia |-- Captorhinidae `--o Romeriida |-- Protorothyrididae `-- Diapsida In contrast, [[Oliver Rieppel|Rieppel]], 1994, 1995; Rieppel & deBraga, 1996; and deBraga & Rieppel, 1997 have argued that turtles are actually related to sauropterygia, and hence are diapsids. The diapsid affinities of turtles have also been supported by [[molecular phylogeny]] (e.g. [[Rafael Zardoya|Zardoya]] and [[Axel Meyer|Meyer]] 1998). If so, this would mean that the Parareptilia would become a wholly extinct clade. However this hypothesis is not very widely accepted among [[vertebrate paleontology|vertebrate paleontologists]], and [[Michael Benton|Benton]] 2000, 2004, retains the traditional class Anapsida for the "parareptiles" and turtles. ==See also== * [[Anapsida]] ==References== * {{cite book|last=Benton|first=M. J.|coauthors=|authorlink=|title=[[Vertebrate Paleontology (Benton)|Vertebrate Paleontology]]|edition=2nd ed.|publisher=Blackwell Science Ltd|location=London|year=2000|isbn=0632056142|series=}}, 3rd ed. 2004 ISBN 0632056371 * {{cite journal|last=deBraga|first=M.|coauthors=Rieppel, O.|year=1997|title=Reptile phylogeny and the interrelationships of turtles|url=|journal=[[Zoological Journal of the Linnean Society]]|issn=|volume=120|issue=3|pages=281–354|doi=10.1006/zjls.1997.0079}} * {{cite journal|last=deBraga|first=M.|coauthors=Reisz, R. R.|year=1996|title=The Early Permian reptile ''Acleistorhinus pteroticus'' and its phylogenetic positio|url=|journal=[[Journal of Vertebrate Paleontology]]|issn=|volume=16|issue=3|pages=384–395 |doi=}} * {{cite book|last=Gauthier|first=J.|coauthors=A. G. Kluge, & T. Rowe|chapter=The early evolution of the Amniota|editor=M. J. Benton (ed.)|title=''The phylogeny and classification of the tetrapods'', Volume 1: amphibians, reptiles, birds|edition=|publisher=[[Clarendon Press]]|location=Oxford|year=1988|isbn=|series=103-155}} * {{cite web|last=Laurin|first=M.|coauthors=Gauthier, J. A.|url=http://tolweb.org/articles/?article_id=462|title=Phylogeny and Classification of Amniotes|date=1996|publisher=at the [[Tree of Life Web Project]]}} * {{cite journal|last=Laurin|first=M.|coauthors=Reisz, R. R.|year=1995|title=A reevaluation of early amniote phylogeny|url=|journal=[[Zoological Journal of the Linnean Society]]|issn=|volume=113|issue=|pages=165–223|doi=}} ([http://www.ingentaconnect.com/content/ap/zj/1995/00000113/00000002/art00007 abstract]) * {{cite journal|last=Olson|first=E. C.|coauthors=|year=1947|title=The family Diadectidae and its bearing on the classification of reptiles|url=|journal=[[Fieldiana Geology]]|issn=0096-2651|volume=11|issue=|pages=1–53|doi=}} * {{cite journal|last=Rieppel|first=O.|coauthors=|year=1994|title=Osteology of ''Simosaurus gaillardoti'' and the relationships of stem-group sauropterygia|url=|journal=Fieldiana Geology|issn=0096-2651|volume=1462|issue=|pages=1–85|doi=}} * {{cite journal|last=Rieppel|first=O.|coauthors=|year=1995|title=Studies on skeleton formation in reptiles: implications for turtle relationships|url=|journal=Zoology-Analysis of Complex Systems|issn=|volume=98|issue=|pages=298–308|doi=}} * {{cite journal|last=Rieppel|first=O.|coauthors=deBraga, M.|year=1996|title=Turtles as diapsid reptiles|url=|journal=[[Nature (journal)|Nature]]|issn=|volume=384|issue=|pages=453–455|doi=}} * {{cite book|last=Romer|first=A. S.|coauthors=|authorlink=|title=[[Vertebrate Paleontology (Romer)|Vertebrate Paleontology]]|edition=3rd edition|publisher=University of Chicago Press|location=Chicago|year=1967|isbn=0-7167-1822-7|series=}} * {{cite journal|last=Zardoya|first=R.|coauthors=Meyer, A.|year=1998|title=Complete mitochondrial genome suggests diapsid affinities of turtles|url=http://www.pubmedcentral.gov/articlerender.fcgi?artid=24355|journal=[[Proceedings of the National Academy of Sciences|Proc Natl Acad Sci U S A]]|issn=0027-8424|volume=95|issue=24|pages=14226–14231|doi=}} ==External links== * [http://www.permiantetrapods.net/PARAREPTILIA.html Parareptilia] * [http://dml.cmnh.org/2001Oct/msg00393.html re Reptilian Subclass Parareptilia?] - [[Dinosaur Mailing List]] archives [[Category:Parareptiles| ]] [[no:Parareptilia]] [[ru:Парарептилии]] [[zh:副爬行動物]]