''Theledectes'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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 th ...

from middle

Triassic The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 ...

(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 ...

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. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...

.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 specime ...

, ''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 sever ...

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, th ...

. This skull was collected by the South African palaeontologist, James W. Kitching 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 fossil ...

, Beaufort Group ( Karoo Basin). The genus was first named by Sean P. Modesto and Ross J. Damiani in 2003. However, the species was initially assigned to the genus '' Thelegnathus'' (now considered to be a '' nomen dubium'') 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. 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 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 Spe ...

''. 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''. In 2008, Juan Carlos Cisneros 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 ...

after Cisneros, 2008:

References

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