Captorhinidae (also known as cotylosaurs) is an extinct family of

tetrapods Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids ( pelycosaurs, extinct therapsi ...

, traditionally considered primitive reptiles, known from the late Carboniferous to the Late

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last ...

. They had a cosmopolitan distribution across

Pangea Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million y ...

Description

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

. Their

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

s 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, ...

, and had teeth that were better able to deal with tough plant material. The postcranial skeleton is very similar to that of advanced

reptiliomorph Reptiliomorpha (meaning reptile-shaped; in PhyloCode known as ''Pan-Amniota'') is a clade containing the amniotes and those tetrapods that share a more recent common ancestor with amniotes than with living amphibians (lissamphibians). It was defi ...

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 s ...

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 (transitiona ...

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 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 Autotomy (from the Greek ''auto-'', "self-" and ''tome'', "severing", αὐτοτομία) or self-amputation, is the behaviour whereby an animal sheds or discards one or more of its own appendages, usually as a self-defense mechanism to elude a ...

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'' 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 postc ...

'' 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

deposits. Captorhinidae contains a single subfamily, the Moradisaurinae. Moradisaurinae was named and assigned to the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

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 Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria t ...

Niger ) , official_languages = , languages_type = National languagesRussia 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-eig ...

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

and Oklahoma. Captorhinids were once thought to be the ancestors of

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked t ...

s. 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'' from

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...

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 th ...

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 ''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 ...

'' ** '' Labidosauriscus'' ** '' Opisthodontosaurus'' ** '' 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 si ...

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

'' ** Subfamily Moradisaurinae *** '' Balearosaurus'' *** '' Captorhinikos'' *** '' Gansurhinus'' *** '' Gecatogomphius''The Paleobiology Database: Moradisaurinae
*** '' Kahneria'' *** '' Labidosaurikos'' *** '' Labidosaurus'' *** '' 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- amniotes instead, as the sister group to '' Protorothyris 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 possi ...

References

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