Captorhinidae (also known as cotylosaurs) is an extinct family of tetrapods, traditionally considered primitive reptiles, known from the late

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carboniferous ...

to the Late Permian. They had a cosmopolitan distribution across Pangea.

Description

Captorhinids are a clade of small to very large lizard-like reptiles that date from the

late Carboniferous Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effe ...

through the Permian. Their skulls were much stronger than those of their relatives, the

Protorothyrididae Protorothyrididae is an extinct family of small, lizard-like reptiles belonging to Eureptilia. Their skulls did not have fenestrae, like the more derived diapsids. Protorothyridids lived from the Late Carboniferous to Early Permian periods, in w ...

, and had teeth that were better able to deal with tough plant material. The

postcrania Postcrania (postcranium, adjective: postcranial) in zoology and vertebrate paleontology is all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g. of dinosaurs or other extinct tetrapods, consist of partial or isolated sk ...

l skeleton is very similar to that of advanced reptiliomorph amphibians, so much in fact that the amphibian

Seymouriamorpha Seymouriamorpha were a small but widespread group of limbed vertebrates (tetrapods). They have long been considered reptiliomorphs, and most paleontologists may still accept this point of view, but some analyses suggest that seymouriamorphs are ...

and

Diadectomorpha Diadectomorpha is a clade of large tetrapods that lived in Euramerica during the Carboniferous and Early Permian periods and in Asia during Late Permian (Wuchiapingian), They have typically been classified as advanced reptiliomorphs (transitional ...

were thought to be reptiles and grouped together in "Cotylosauria" as the first reptiles in the early 20th century. Captorhinids have broad, robust skulls that are generally triangular in shape when seen in dorsal view. The

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has ...

e are characteristically downturned. The largest captorhinid, the herbivorous '' Moradisaurus'', could reach an estimated snout-vent length of 2 meters (6.5 feet). Early, smaller forms possessed single rows of teeth, and were likely carnivorous or omnivorous, while the larger, more

derived Derive may refer to: *Derive (computer algebra system), a commercial system made by Texas Instruments * ''Dérive'' (magazine), an Austrian science magazine on urbanism *Dérive, a psychogeographical concept See also * *Derivation (disambiguation ...

captorhinids belonging to the subfamily Moradisaurinae were herbivorous and developed multiple (up to 11) rows of teeth in the jaws alongside propalinal (back and forth) jaw motion, which created an effective apparatus for grinding and shredding plant matter.Histological and SEM analysis of captorhinid tail vertebrae concluded in a 2018 study that captorhinids were the first amniotes to develop caudal autotomy as a defensive function. In studied specimens a split line is present in certain caudal vertebrae that is similar to those found in modern reptiles that perform caudal autonomy. This behaviour represented significant evolutionary benefit for the animals, allowing for escape and distracting predators, as well as minimizing blood loss at an injury site.

Discovery and history

Until recently, ''

Concordia cunninghami ''Euconcordia'' is an extinct genus of Late Carboniferous captorhinid known from Greenwood County, Kansas of the United States. Description ''Euconcordia'' is known from the holotype KUVP 8702a&b, well preserved skull in dorsal view along ...

'' was thought to be the basalmost known member of Captorhinidae. A novel phylogenic study of primitive reptile relationships by Muller & Reisz in 2006 recovered ''

Thuringothyris ''Thuringothyris'' is an extinct genus of Early Permian eureptiles known from the Thuringian Forest in central Germany. Description ''Thuringothyris'' is known from the holotype MNG 7729, articulated well-preserved skull and partial postcra ...

'' as a sister taxon of the Captorhinidae.Muller, J. and Reisz, R.R. (2006). "The phylogeny of early eureptiles: Comparing parsimony and Bayesian approaches in the investigation of a basal fossil clade." ''Systematic Biology'', 55(3):503-511. The same results were obtained in later phylogenic analyses. ''Concordia'' is still the earliest known captorhinid as all other captorhinid taxa are known only from Permian deposits. Captorhinidae contains a single subfamily, the Moradisaurinae. Moradisaurinae was named and assigned to the family Captorhinidae by A. D. Ricqlès and P. Taquet in 1982. Moradisaurinae was defined as "all captorhinids more closely related to ''Moradisaurus'' than to ''

Captorhinus ''Captorhinus'' (from el, καπτō , 'to gulp down' and el, ῥῑνός , 'nose') is an extinct genus of captorhinid reptiles that lived during the Permian period. Its remains are known from Oklahoma, Texas, Europe, India, the Pedra de Fog ...

''". The moradisaurines inhabited what is now China, Morocco, Niger,

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eight ...

, Texas and Oklahoma. Captorhinids were once thought to be the ancestors of turtles. The

Middle Permian The Guadalupian is the second and middle series/ epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± ...

reptile ''

Eunotosaurus ''Eunotosaurus'' (''Latin'': Stout-backed lizard) is an extinct genus of amniote, possibly a close relative of turtles. ''Eunotosaurus'' lived in the late Middle Permian (Capitanian stage) and fossils can be found in the Karoo Supergroup of Sout ...

'' from South Africa was seen as the " missing link" between cotylosaurs and chelonians throughout much of the early 20th century. However, more recent fossil finds have shown that ''Eunotosaurus'' is a

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 the ...

unrelated to either turtles or captorhinids.

Classification

Taxonomy

The following taxonomy follows Reisz ''et al.'', 2011 and Sumida ''et al.'', 2010 unless otherwise noted. *Family Captorhinidae ** '' Captorhinoides''? ** '' Acrodenta'' ** '' Baeotherates'' ** ''

'' ** '' Euconcordia'' ** '' Labidosauriscus'' ** ''

Opisthodontosaurus ''Opisthodontosaurus'' is an extinct genus of captorhinid reptile from the Early Permian of Oklahoma. The type species ''Opisthodontosaurus carrolli'' was named in 2015 on the basis of several articulated skeletons from the Dolese Brothers Limest ...

'' ** '' Protocaptorhinus'' ** '' Reiszorhinus'' ** '' Rhiodenticulatus'' ** ''

Romeria Christianity has a strong tradition of pilgrimages, both to sites relevant to the New Testament narrative (especially in the Holy Land) and to sites associated with later saints or miracles. History Christian pilgrimages were first made to sit ...

'' ** '' Saurorictus'' ** ''

'' ** Subfamily Moradisaurinae *** '' Balearosaurus'' *** '' Captorhinikos'' *** ''

Gansurhinus ''Gansurhinus'' is an extinct genus of moradisaurine captorhinid known from the Middle Permian Qingtoushan Formation of the Qilian Mountains and the Late Permian Naobaogou Formation in the Daqing Mountains of China. It was first named by Robe ...

'' *** '' Gecatogomphius''The Paleobiology Database: Moradisaurinae
*** '' Kahneria'' *** ''

Labidosaurikos ''Labidosaurikos'' is a genus of extinct captorhinid anapsid reptile that lived around 279 to 272 million years ago during Kungurian age of the lower Permian. The American paleontologist John Willis Stovall first described ''Labidosaurikos'' in 1 ...

'' *** ''

Labidosaurus ''Labidosaurus'' (from el, λᾰβῐ́δος , 'forceps' and el, σαῦρος , 'lizard') is an extinct genus of reptile from the Permian period of North America. Fossils have been discovered in Texas. It was heavily built, resembling a liza ...

'' *** '' Moradisaurus'' *** '' Rothianiscus'' *

Dubious Doubt is a mental state in which the mind remains suspended between two or more contradictory propositions, unable to be certain of any of them. Doubt on an emotional level is indecision between belief and disbelief. It may involve uncertainty ...

Captorhinids ** '' Puercosaurus'' ** '' Riabininus''

Phylogeny

The

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 ...

below was recovered in a study by Sumida ''et al.'', 2010. The cladogram below follows the topology from a 2011 analysis by paleontologists Robert R. Reisz, Jun Liu, Jin-Ling Li and Johannes Müller. The majority of phylogenetic studies recover captorhinids as basal members of Eureptilia; however, Simões ''et al.'' (2022) recover them as stem-

amniote Amniotes are a clade of tetrapod vertebrates that comprises sauropsids (including all reptiles and birds, and extinct parareptiles and non-avian dinosaurs) and synapsids (including pelycosaurs and therapsids such as mammals). They are distin ...

s instead, as the sister group to ''

Protorothyris ''Protorothyris'' is an extinct genus of Early Permian protorothyridid known from Texas and West Virginia of the United States. It was first named by Llewellyn Ivor Price in 1937 and the type species is ''Protorothyris archeri''. ''P. archeri'' ...

archeri'', while the clade including captorhinids and ''P. archeri'' is recovered as the sister group to

Araeoscelidia Araeoscelidia or Araeoscelida is a clade of extinct diapsid reptiles superficially resembling lizards, extending from the Late Carboniferous to the Early Permian. The group contains the genera '' Araeoscelis'', '' Petrolacosaurus'', the possibly ...

References

{{Taxonbar, from=Q141936 Prehistoric reptile families Carboniferous reptiles Permian reptiles Pennsylvanian first appearances Lopingian extinctions Taxa named by Ermine Cowles Case