''Theledectes'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 ("near-reptiles") is an extinct group of Basal (phylogenetics), basal Sauropsida, sauropsids ("Reptile, reptiles"), traditionally considered the sister taxon to Eureptilia (the group that likely contains all living reptiles and birds ...

from middle

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

(early

Anisian In the geologic timescale, the Anisian is the lower stage (stratigraphy), stage or earliest geologic age, age of the Middle Triassic series (stratigraphy), series or geologic epoch, epoch and lasted from million years ago until million years ag ...

stage) deposits of Free State Province,

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

.The

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

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

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

BP/1/4585, a flattened

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

. 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 palaeontologist and regarded as one of the world’s greatest fossil finders. Career His work in the southern hemisphere, including Antarctica, led ...

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 Lithostratigraphy, lithostratigraphic Geological formation, formation in the Beauf ...

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 fossili ...

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 under ...

(

Karoo Basin The Karoo Supergroup is the most widespread stratigraphic unit in Africa south of the Kalahari Desert. The supergroup consists of a sequence of units, mostly of nonmarine origin, deposited between the Late Carboniferous and Early Jurassic, a per ...

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

2003 2003 was designated by the United Nations as the International Year of Fresh water, Freshwater. In 2003, a Multi-National Force – Iraq, United States-led coalition 2003 invasion of Iraq, invaded Iraq, starting the Iraq War. Demographic ...

. 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 ...

'') 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 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 Captorhinids are a clade of sm ...

. The lower jaw has two large incisor-like teeth, akin to '' Scoloparia''. 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 , 'height' and , 'jaw') is an extinct genus of procolophonid parareptile from the Late Triassic of New Jersey, Connecticut, and Nova Scotia. ''Hypsognathus'' resembled a moderately sized lizard, with a length of , alth ...

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

Classification

Cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

after Cisneros, 2008:

References

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