''Theledectes'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of theledectine

procolophonid Procolophonidae is an extinct family of small, lizard-like parareptiles known from the Late Permian to Late Triassic that were distributed across Pangaea, having been reported from Europe, North America, China, South Africa, South America, Antarc ...

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 ...

from middle

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

(early

Anisian In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from million years ago until million years ago. The Anisian Age succeeds the Olenekian Age (part of the Lower Triassic Ep ...

stage) deposits of Free State Province,

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

.The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

, ''Theledectes perforatus'', is based on the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

BP/1/4585, a flattened

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, the ...

. This skull was collected by the South African palaeontologist,

James W. Kitching James William Kitching (6 February 1922 – 24 December 2003) was a South African vertebrate paleontology, vertebrate palaeontologist and regarded as one of the world’s greatest fossil finders. Career His work in the southern hemisphere, in ...

from Hugoskop in the Rouxville District and referred to subzone B of the

Cynognathus Assemblage Zone The ''Cynognathus'' Assemblage Zone is a tetrapod biozone utilized in the Karoo Basin of South Africa. It is equivalent to the Burgersdorp Formation, the youngest lithostratigraphic formation in the Beaufort Group, which is part of the fossilife ...

of the

Burgersdorp Formation The ''Cynognathus'' Assemblage Zone is a tetrapod biozone utilized in the Karoo Basin of South Africa. It is equivalent to the Burgersdorp Formation, the youngest lithostratigraphic formation in the Beaufort Group, which is part of the fossilife ...

Beaufort Group The Beaufort Group is the third of the main subdivisions of the Karoo Supergroup in South Africa. It is composed of a lower Adelaide Subgroup and an upper Tarkastad Subgroup. It follows conformably after the Ecca Group and unconformably underlie ...

(

Karoo Basin The Karoo Supergroup is the most widespread stratigraphy, stratigraphic unit in Africa south of the Kalahari Desert. The group (stratigraphy), supergroup consists of a sequence of units, mostly of nonmarine origin, deposited between the Pennsylvan ...

). The genus was first named by Sean P. Modesto and Ross J. Damiani in

2003 File:2003 Events Collage.png, From top left, clockwise: The crew of STS-107 perished when the Space Shuttle Columbia disintegrated during reentry into Earth's atmosphere; SARS became an epidemic in China, and was a precursor to SARS-CoV-2; A des ...

. However, the species was initially assigned to the genus '' Thelegnathus'' (now considered to be a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

'') by C.E. Gow in 1977, as the species ''Thelegnathus perforatus''.

Description

Most of the skull is poorly preserved, with the exception of the tooth-bearing elements. ''Theledectes'' is the only known parareptile with more than one row of marginal teeth (teeth along the edge of the mouth). The only other reptiles with multiple marginal tooth rows are

rhynchosaurs Rhynchosaurs are a group of extinct herbivorous Triassic archosauromorph reptiles, belonging to the order Rhynchosauria. Members of the group are distinguished by their triangular skulls and elongated, beak like premaxillary bones. Rhynchosaurs ...

and some

captorhinids Captorhinidae (also known as cotylosaurs) is an extinct family of tetrapods, traditionally considered primitive reptiles, known from the late Carboniferous to the Late Permian. They had a cosmopolitan distribution across Pangea. Description C ...

. The lower jaw has two large incisor-like teeth, akin to ''

Scoloparia ''Scoloparia'' is an extinct genus of procolophonid parareptile from the Triassic of Canada. Fossils have been found in the Early Triassic to Norian-age Wolfville Formation in Nova Scotia, Canada Canada is a country in North America. ...

''. However, the dentition is also distinctly inset from the rest of the face by a large curved area, a trait also known in ''

Hypsognathus ''Hypsognathus'' (from el, ῠ̔́ψος , 'height' and el, γνάθος , 'jaw') is an extinct genus of procolophonid parareptile from the Late Triassic of New Jersey, Connecticut, and Nova Scotia.Sues, H.-D.,Olsen, P.E., Scott,D.M, and Spenc ...

''. The teeth are large and blunted cones, with circular bases, in contrast to most procolophonids which have teeth that are wider than long. Similar teeth are also observed in ''"Eumetabolodon" dongshengensis'', a Chinese procolophonid previously considered a species of ''

Eumetabolodon ''Eumetabolodon'' is an extinct genus of procolophonine procolophonid parareptile from early and middle Triassic (Induan to earliest Anisian stages) deposits of Nei Mongol, northern China. Two species of ''Eumetabolodon'' were named by J. L. Li i ...

''. In 2008,

Juan Carlos Cisneros Juan Carlos Cisneros (born May 18, 1977 in Buenos Aires, Argentina) is a former Argentine footballer. He played for Clubs of Argentina, Chile, Bolivia and Paraguay. Teams * Deportivo Español 1997-1999 * Cipolletti 1999-2000 * Colo-Colo 2000 * ...

named the subfamily Theledectinae to encompass ''Theledectes'' and ''"E." dongshengensis''.

Classification

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 d ...

after Cisneros, 2008:

References

Procolophonids Middle Triassic reptiles of Africa Fossil taxa described in 2003 Anisian life Prehistoric reptile genera {{triassic-reptile-stub