# Sclerothorax > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Sclerothorax > Markdown URL: https://mediated.wiki/source/Sclerothorax.md > Source: https://en.wikipedia.org/wiki/Sclerothorax > Source revision: 1323253615 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) Extinct genus of temnospondyls Sclerothorax Temporal range: Early Triassic, Olenekian PreꞒ Ꞓ O S D C P T J K Pg N Fossil Scientific classification Kingdom: Animalia Phylum: Chordata Clade: Tetrapoda Order: †Temnospondyli Suborder: †Stereospondyli Clade: †Capitosauria Family: †Sclerothoracidae Huene, 1932 Genus: †Sclerothorax Huene, 1932 Type species †Sclerothorax hypselonotus Huene, 1932 ***Sclerothorax*** is an extinct [genus](/source/Genus) of [temnospondyl](/source/Temnospondyl) from the [Early Triassic](/source/Early_Triassic) of Germany. It is distinguished from other temnospondyls by its short and very wide skull and the elongated [neural spines](/source/Neural_spine) that form a ridge along its back. *Sclerothorax* is a [basal](/source/Basal_(phylogenetics)) member of [Capitosauria](/source/Capitosauria), a large [clade](/source/Clade) of temnospondyls that lived throughout the Triassic.[1] ## Description Restoration Among the most unusual features of *Sclerothorax* are its elongated neural spines. The neural spines are tallest at the front of the spine. *Sclerothorax* also has a very large [pectoral girdle](/source/Pectoral_girdle); the [interclavicle](/source/Interclavicle) bone is longer than the skull, meaning that *Sclerothorax* has the proportionally largest interclavicle of any temnospondyl. The body of *Sclerothorax* is covered by small scale-like bony ossicles that would have been embedded in the [dermis](/source/Dermis) in life. The skull of *Sclerothorax* is short, wide, and roughly rectangular in shape. The snout is wider than the cheek region. The bones along the midline of the [skull roof](/source/Skull_roof) are also very wide relative to those of other temnospondyls.[1] ## Discovery Two fossil specimens of *Sclerothorax* were discovered in the German state of [Hesse](/source/Hesse) in the 1920s. German paleontologist [Friedrich von Huene](/source/Friedrich_von_Huene) studied the remains and named the new genus and species *Sclerothorax hypselonotus* in 1932. The [holotype](/source/Holotype) specimen preserved only the vertebral column, but was identifiable as a temnospondyl by its [rhachitomous](/source/Rachitomi) vertebrae and as a new species by its tall neural spines. Huene's second specimen included a complete skull, [pectoral girdle](/source/Pectoral_girdle), and back portion of the [dorsal vertebral](/source/Dorsal_vertebra) column that was also clearly a temnospondyl. However, it was not apparent that the specimen belonged to the same species as the first until Huene exposed more of the crushed vertebrae and found that they were similar to those of his first specimen.[1] A third specimen of *Sclerothorax* was discovered in 1967 that preserved the vertebral column and the lower jaw. It was described in 2004 by Michael Fastnacht, who also reported that the specimen had an impression of the [palate](/source/Palate). The palate seemed to be long and narrow like that of another German temnospondyl called *[Trematosaurus](/source/Trematosaurus)*. Fastnacht therefore concluded that Huene's two specimens belonged to different species, with the first high-spined specimen referable to *Sclerothorax*. However, three more specimens were uncovered in German museum collections with nearly complete skulls attached to vertebral columns. These specimens had broad heads, proving that Huene's second specimen also belongs to *Sclerothorax*.[1] ## Classification Restoration Huene originally classified *Sclerothorax* within the family [Actinodontidae](/source/Actinodontidae) as a close relative of *[Sclerocephalus](/source/Sclerocephalus)*, another genus of temnospondyl from Germany that has a similarly broad skull. This classification put it as a close relative of a major temnospondyl group called [Stereospondyli](/source/Stereospondyli), characterized by [centra](/source/Body_of_vertebra) (central portions of vertebrae) that are primarily formed by bones called [intercentra](https://en.wikipedia.org/w/index.php?title=Intercentra&action=edit&redlink=1) (non-stereospondyl temnospondyls have an additional bone called the [pleurocentrum](https://en.wikipedia.org/w/index.php?title=Pleurocentrum&action=edit&redlink=1) that forms a significant portion of each vertebra). The unusual vertebrae of *Sclerothorax* were thought to separate it from stereospondyls, but in 2000 it was reinterpreted as a tentative member of the group. A [phylogenetic analysis](/source/Phylogenetics) published in 2007 placed *Sclerothorax* as a [derived](/source/Synapomorphy) stereospondyl in a clade called Capitosauria.[1] ## References 1. ^ [***a***](#cite_ref-SFFK07_1-0) [***b***](#cite_ref-SFFK07_1-1) [***c***](#cite_ref-SFFK07_1-2) [***d***](#cite_ref-SFFK07_1-3) [***e***](#cite_ref-SFFK07_1-4) Schoch, R.R.; Fastnacht, M.; Fichter, J.; Keller, T. (2007). ["Anatomy and relationships of the Triassic temnospondyl *Sclerothorax*"](https://www.app.pan.pl/archive/published/app52/app52-117.pdf) (PDF). *Acta Palaeontologica Polonica*. **52** (1): 117–136. - [Paleontology portal](https://en.wikipedia.org/wiki/Portal:Paleontology) v t e Stereospondyli Kingdom: Animalia Phylum: Chordata Clade: Tetrapodomorpha Order: Temnospondyli Tetrapodomorpha see Tetrapodomorpha Temnospondyli see Temnospondyli Stereospondyli see below↓ Stereospondyli Stereospondyli Arachana Capulomala Peltobatrachus Lapillopsidae Lapillopsis Manubrantlia Rhigerpeton Rotaurisaurus Rhinesuchidae Australerpeton? Broomistega Laccosaurus Parapytanga? Rastosuchus Rhineceps Rhinesuchoides Rhinesuchus Uranocentrodon Lydekkerinidae Chomatobatrachus Cryobatrachus Deltacephalus Eolydekkerina Indobenthosuchus Luzocephalus? Lydekkerina Capitosauria Antarctosuchus Bukobaja Calmasuchus Capitosaurus Cherninia Cyclotosaurus Edingerella Eocyclotosaurus Eryosuchus Heptasaurus Huangfuchuansuchus Jammerbergia Kestrosaurus Kupferzellia Mastodonsaurus Meyerosuchus Odenwaldia Paracyclotosaurus Parotosuchus Quasicyclotosaurus Procyclotosaurus Promastodonsaurus Rhadalognathus Samarabatrachus Sassenisaurus Sclerothorax Selenocara Stanocephalosaurus Stenotosaurus Subcyclotosaurus Tatrasuchus Vladlenosaurus Volgasaurus Volgasuchus Warrenisuchus Watsonisuchus Wellesaurus Wetlugasaurus Xenotosuchus Yuanansuchus Trematosauria see below↓ Trematosauria Trematosauria Almasaurus Bothriceps Callistomordax Chinlestegophis Keratobrachyops Laidleria Latiscopus Qantas Rileymillerus Syrtosuchus Uruyiella Benthosuchidae Benthosuchus Kwatisuchus Trematosauridae Angusaurus Aphaneramma Cosgriffius Erythrobatrachus Gonioglyptus Hyperokynodon Icanosaurus Indolyrocephalus Inflectosaurus Lyrocephaliscus Microposaurus Panchetosaurus Platystega Prothoosuchus Stoschiosaurus Tertrema Tertremoides Thoosuchus Tirraturhinus Trematolestes Trematosuchoides Trematosaurus Trematosuchus Trematotegmen Wantzosaurus Metoposauridae Anaschisma Apachesaurus Arganasaurus Buettnererpeton Dutuitosaurus Metoposaurus Panthasaurus Rhytidosteidae Boreopelta Mahavisaurus Nanolania Peltostega Pneumatostega Rhytidosteus Sangaia Trucheosaurus Derwentiinae Arcadia Acerastia Deltasaurus Derwentia Indobrachyops Rewana Chigutisauridae Arenaerpeton Chigutisaurus Compsocerops Koolasuchus Pelorocephalus Siderops Brachyopidae Banksiops Bathignathus Batrachosaurus Batrachosuchoides Batrachosuchus Blinasaurus Brachyops Gobiops Hadrokkosaurus Notobrachyops Platycepsion Sinobrachyops Vanastega Vigilius Xenobrachyops Plagiosauridae Gerrothorax Megalophthalma Plagiobatrachus Plagiorophus Plagiosaurus Plagioscutum Plagiosternum Plagiosuchus See also: Trematosauroidea Metoposauroidea Rhytidosteoidea Brachyopomorpha Brachyopoidea Plagiosauroidea Category Taxon identifiers Sclerothorax hypselonotus Wikidata: Q2570648 GBIF: 8487291 Paleobiology Database: 248239 --- Adapted from the Wikipedia article [Sclerothorax](https://en.wikipedia.org/wiki/Sclerothorax) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Sclerothorax?action=history)). 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