Procolophonia
From Wikipedia, the free encyclopedia
| Procolophonians Temporal range: Guadalupian - Late Triassic, | |
|---|---|
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| Pareiasaurus (Pareiasauromorpha) | |
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| Sclerosaurus (Procolophonoidea) | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| 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 until 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.[1][2][3][4]
Procolophonians show the development of a fossa (depression) on the supratemporal bone, which is suggested to have supported a tympanic membrane for hearing, unlike most other "parareptiles". Tympanic hearing is also thought to have convergently evolved in the common ancestor of millerettids and neodiapsids (the ancestral group of modern reptiles and birds), which was supported by different bones.[2]
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.[5] 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.[6]
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.[6]
| Parareptilia |
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In a 2022, study, Simoes et al (2022) proposed that Parareptilia was paraphyletic, and that procolophonians were closely related to neodiapsids as part of the clade Neoreptilia.[7] More recent studies have supported the paraphyly of Parareptilia, but have instead found procolophonians in a slightly more basal position among the earliest diverging neoreptiles.[2][4][8]
| Reptiliomorpha |
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Cladogram after Jenkins et al. 2025:[2]
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