Procolophonia

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Procolophonians
Temporal range: Guadalupian - Late Triassic, 272.3–201.3  Ma
Pareiasaurus serridens.jpg
Pareiasaurus (Pareiasauromorpha)
Sclerosaurus1DB.jpg
Sclerosaurus (Procolophonoidea)
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Subclass: Parareptilia
Order: Procolophonomorpha
Clade: Ankyramorpha
Suborder: Procolophonia
Seeley, 1888
Subgroups

Procolophonia is an extinct clade of basal reptiles, traditionally classified as "parareptiles", that lived from the Middle Permian till the end of the Triassic period. The group includes the largest known parareptiles, the up to oxen-sized herbivorous pareiasaurs, as well as the longest lived "parareptiles", the small lizard-like procolophonoids. Although traditionally grouped in Parareptilia, this classification scheme has been questioned.

Contents

Classification

There are two main groups of Procolophonia, the small, lizard-like Procolophonoidea, and the Pareiasauroidea, which include the large, armoured Pareiasauridae. According to the traditional classification of Carroll 1988 as well as phylogenetic analyses of 2012, smaller groups like Rhipaeosauridae (now a synonym of Nycteroleteridae) and Sclerosauridae are classified with the pareiasaurs and with the procolophonids, respectively. [1] The Nyctiphruretidae was thought to represent the sister taxon of Procolophonia by many studies, however recently discovered material places it within the group, as the sister taxon of Procolophonoidea. [2]

The following cladogram is simplified after the phylogenetic analysis of MacDougall and Reisz (2014) and shows the placement of Procolophonia within Parareptilia. Relationships within bolded terminal clades are not shown. [2]

Parareptilia

In a 2022, study, Simoes et al (2022) proposed that Parareptilia was paraphyletic, and that procolphonians were closely related to neodiapsids as part of the clade Neoreptilia. [3]

Reptiliomorpha

Relationship to turtles

The procolophonians were traditionally thought to be ancestral to the turtles, although experts disagreed over whether turtle ancestors would be found among the Procolophonidae, the Pareiasauridae (Lee 1995,1996, 1997), or simply a generic Procolophonian ancestor. Laurin & Reisz, 1995 and Laurin & Gauthier 1996 defined the Procolophonia cladistically as "The most recent common ancestor of pareiasaurs, procolophonids, and testudines (Chelonia), and all its descendants", and listed a number of autapomorphies. However, Rieppel and deBraga 1996 and deBraga & Rieppel, 1997 argued that turtles evolved from sauropterygians, which would mean that the Parareptilia and Procolophonia constitute wholly extinct clades that are only distantly related to living reptiles. The first genome-wide phylogenetic analysis of turtle relationships was completed by Wang et al. (2013). Using the draft genomes of Chelonia mydas and Pelodiscus sinensis, the team used the largest turtle data set to date in their analysis and concluded that turtles are likely a sister group of crocodilians and birds (Archosauria). [4] This placement within the diapsids suggests that the turtle lineage lost diapsid skull characteristics as it now possesses an anapsid skull.

References

Notes
  1. Linda A. Tsuji, Johannes Müller and Robert R. Reisz (2012). "Anatomy of Emeroleter levis and the Phylogeny of the Nycteroleter Parareptiles". Journal of Vertebrate Paleontology. 32 (1): 45–67. doi:10.1080/02724634.2012.626004.
  2. 1 2 Mark J. MacDougall and Robert R. Reisz (2014). "The first record of a nyctiphruretid parareptile from the Early Permian of North America, with a discussion of parareptilian temporal fenestration". Zoological Journal of the Linnean Society. 172 (3): 616–630. doi:10.1111/zoj.12180.
  3. Simões, T. R.; Kammerer, C. F.; Caldwell, M. W.; Pierce, S. E. (2022). "Successive climate crises in the deep past drove the early evolution and radiation of reptiles". Science Advances. 8 (33): eabq1898. Bibcode:2022SciA....8.1898S. doi: 10.1126/sciadv.abq1898 . PMC   9390993 . PMID   35984885.{{cite journal}}: CS1 maint: article number as page number (link)
  4. Wang, Zhuo; Pascual-Anaya, J; Zadissa, A; Li, W; Niimura, Y; Huang, Z; Li, C; White, S; Xiong, Z; Fang, D; Wang, B; Ming, Y; Chen, Y; Zheng, Y; Kuraku, S; Pignatelli, M; Herrero, J; Beal, K; Nozawa, M; Li, Q; Wang, J; Zhang, H; Yu, L; Shigenobu, S; Wang, J; Liu, J; Flicek, P; Searle, S; Wang, J; et al. (27 March 2013). "The draft genomes of soft-shell turtle and green sea turtle yield insights into the development and evolution of the turtle-specific body plan". Nature Genetics. 45 (701–706): 701–6. doi:10.1038/ng.2615. PMC   4000948 . PMID   23624526.
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