''Stegotretus'' is an extinct

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 ...

lepospondyl Lepospondyli is a diverse taxon of early tetrapods. With the exception of one late-surviving lepospondyl from the Late Permian of Morocco (''Diplocaulus minumus''), lepospondyls lived from the Early Carboniferous ( Mississippian) to the Early Per ...

microsaur Microsauria ("small lizards") is an extinct, possibly polyphyletic order of tetrapods from the late Carboniferous and early Permian periods. It is the most diverse and species-rich group of lepospondyls. Recently, Microsauria has been considere ...

referred to the

Pantylidae Pantylidae is an extinct family of lepospondyl amphibians and often considered a sister-group to the family Tuditanidae. The family contains two genera ''Pantylus'' and ''Stegotretus'', while a third, ''Sparodus ''Sparodus'' is an extinct g ...

. It is known from the

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 ''Carbonifero ...

–

Permian The Permian ( ) is a geologic period and 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 period of the Paleoz ...

boundary

Cutler Formation The Cutler Formation or Cutler Group is a rock unit that is exposed across the U.S. states of Arizona, northwest New Mexico, southeast Utah and southwest Colorado. It was laid down in the Early Permian during the Wolfcampian epoch. Descript ...

exposures of

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ker ...

History of study

Material now referred to ''Stegotretus'' was first described (in brief) by Eberth & Berman (1983). It was formally named by Berman et al. (1988). The genus name comes from the Greek ''stegos'' ('roof') and ''tretos'' ('perforated') to refer to a large fenestra found on the

palatine A palatine or palatinus (in Latin; plural ''palatini''; cf. derivative spellings below) is a high-level official attached to imperial or royal courts in Europe since Roman times.

bone. The species name, ''S. agyrus'', is said to be derived from Greek ''agyrus'' ('gathering' / 'crowd') in reference to the concentration of all known specimens in a small area. The proper word in ancient Greek for 'gathering' / 'crowd' is however ''agora'' (ἀγορά), with the variant ''agyris'' (ἄγυρις) in the

Aeolic In linguistics, Aeolic Greek (), also known as Aeolian (), Lesbian or Lesbic dialect, is the set of dialects of Ancient Greek spoken mainly in Boeotia; in Thessaly; in the Aegean island of Lesbos; and in the Greek colonies of Aeolis in Anatolia ...

dialect.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. Revised and augmented throughout by Sir Henry Stuart Jones with the assistance of Roderick McKenzie.''Oxford: Clarendon Press. The holotype and referred materials are currently reposited in the

Carnegie Museum of Natural History The Carnegie Museum of Natural History (abbreviated as CMNH) is a natural history museum in the Oakland neighborhood of Pittsburgh, Pennsylvania. It was founded by Pittsburgh-based industrialist Andrew Carnegie in 1896. Housing some 22 millio ...

. A large number of partial to complete skulls and associated postcrania are known for this taxon.

Anatomy

Despite the large number of specimens of ''Stegotretus'', many are poorly preserved or distorted. ''Stegotretus'' is diagnosed by the presence of only two premaxillary teeth and by a large circular fenestra on the palatine. A contact between the maxilla and the quadratojugal and the absence of an entepicondylar foramen on the humerus separate it from the purportedly closely related ''

Pantylus ''Pantylus'' (from el, παν , 'all' and el, τύλος , 'knob') is an extinct lepospondyl amphibian from the Permian period of North America. ''Pantylus'' was probably a largely terrestrial animal, judging from its well-built legs. It was ...

''.

Relationships

''Stegotretus'' was classified as a pantylid by Berman et al. (1988). This has been validated by phylogenetic analyses that include the taxon, although it is sometimes recovered as being more closely related to ''

Sparodus ''Sparodus'' is an extinct genus of microsaur within the family Gymnarthridae. See also * Prehistoric amphibian * List of prehistoric amphibians This list of prehistoric amphibians is an attempt to create a comprehensive listing of all genera ...

'' than to ''Pantylus'' when all three taxa are sampled. Below is the result of the analysis by Huttenlocker et al. (2013):

References

{{Taxonbar, from=Q7606720 Carboniferous amphibians of North America Recumbirostrans Cisuralian amphibians of North America Paleozoic amphibians of North America Fossil taxa described in 1988