Plagiosuchus

Plagiosuchus Temporal range: Triassic, 242.0–235 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Order:	†Temnospondyli
Suborder:	†Stereospondyli
Family:	†Plagiosauridae
Genus:	†Plagiosuchus Huene, 1922
Type species
† Plagiosuchus pustuliferus Fraas, 1896

Plagiosuchus is an extinct genus of plagiosaurid temnospondyl. It is known from several collections from the Middle Triassic of Germany.

History of study

The type and only species of Plagiosuchus, P. pustuliferus, was originally described as a species of Plagiosternum, with the specific epithet as 'pustuliferum' by Eberhard Fraas in 1896.^[1] The interclavicle described and figured by Fraas had originally been noted by him as Labyrinthodon sp. in an 1889 publication^[2] and before that by von Meyer and Plienenger in a 1844 publication.^[3] This interclavicle was not formalized as the holotype but is recognized as the lectotype. The taxon was reassigned to the newly named genus Plagiosuchus in 1922 by von Huene, who described new material that permitted him to differentiate it from Plagiosternum granulosum; this was also when the specific epithet was grammatically modified.^[4] Additional material was referenced and briefly figured by Hellrung (2003)^[5] and Werneburg and Witter (2005),^[6] but most of the osteology comes from the description of a complete skull, figured by Hellrung, by Damiani et al. (2009).^[7] Histology of the osteoderms^[8] and the limbs^[9][10] has also been analyzed.

Anatomy

Plagiosuchus has a relatively long skull for a plagiosaurid, approximately as long as it is wide. However, its most defining feature is its greatly enlarged orbit, which forms a massive orbitotemporal fenestra with the loss of several post-orbital bones, including the postfrontal and the postorbital, and the reduction of several others.^[7] This fenestra is about 80% of the total length of the skull. The subtemporal vacuity on the palate is also correspondingly long, while the tooth rows are short, confined to the anterior portion of the skull. Ornamentation varies across the skeleton, with the distinct pustules found in many other plagiosaurids found on the pectoral elements, more typical temnospondyl ridging on the mandible, and more irregular large tubercles on the skull.^[11]

See also

• Prehistoric amphibian
• List of prehistoric amphibians

References

1. Fraas, Eberhard (1896). Die schwäbischen Trias-Saurier nach dem Material der Kgl. Naturalien-Sammlung in Stuttgart zusammengestellt. E. Schweizerbart'sche Verlagshandlung. pp. 1–18.
2. Fraas, Eberhard. (1889). Die Labyrinthodonten der schwäbischen Trias. [With plates.]. OCLC 559337958.
3. Meyer, Hermann von Geologe, 1801-1869. (1844). Beiträge zur Paläontologie Württembergs, enthaltend die fossilen Wirbelthierreste aus den Triasgebilden mit besonderer Rücksicht auf die Labyrinthodonten des Keupers. OCLC 602914927.
4. Huene, Friedrich (1922). "BEITRäGE ZUR KENNTNIS DER ORGANISATION EINIGER STEGOCEPHALEN DER SCHWäBISCHEN TRIAS". Acta Zoologica. 3 (2–3): 395–400. doi:10.1111/j.1463-6395.1922.tb01025.x. ISSN 0001-7272.
5. Hellrung, Hanna. (2003). Gerrothorax pustuloglomeratus, ein Temnospondyle (Amphibia) mit knöcherner Branchialkammer aus dem Unteren Keuper von Kupferzell (Süddeutschland) = Gerrothorax pustuloglomeratus, a temnospondyle (Amphibia) with a bony branchial chamber from the Lower Keuper of Kupferzell (South Germany). Staatliches Museum für Naturkunde. OCLC 492485374.
6. Werneburg, Ralf; Witter, Wolfram (2005). "Fossillagerstätten im Unteren Keuper Thüringens (Erfurt-Formation, MittelTrias). Teil 2: ICE-Trasse nördlich der BAB 71-Ausfahrt 'Arnstadt-Nord'". Veröffentlichungen des Naturhistorischen Museums Schleusingen. 20: 57–75.
7. Damiani, Ross; Schoch, Rainer R.; Hellrung, Hanna; Werneburg, Ralf; Gastou, Stephanie (2009). "The plagiosaurid temnospondylPlagiosuchus pustuliferus(Amphibia: Temnospondyli) from the Middle Triassic of Germany: anatomy and functional morphology of the skull". Zoological Journal of the Linnean Society. 155 (2): 348–373. doi:10.1111/j.1096-3642.2008.00444.x. ISSN 0024-4082.
8. Witzmann, Florian; Soler-Gijón, Rodrigo (2010). "The bone histology of osteoderms in temnospondyl amphibians and in the chroniosuchianBystrowiella". Acta Zoologica. 91 (1): 96–114. doi:10.1111/j.1463-6395.2008.00385.x. ISSN 0001-7272.
9. Konietzko-Meier, D.; Schmitt, A. (2013). "A histological study of a femur of Plagiosuchus, a Middle Triassic temnospondyl amphibian from southern Germany, using thin sections and micro-CT scanning". Netherlands Journal of Geosciences. 92 (2–3): 97–108. Bibcode:2013NJGeo..92...97K. doi:10.1017/s0016774600000020. ISSN 0016-7746. S2CID 131811136.
10. Sanchez, S.; Schoch, R. R. (2013-05-22). "Bone Histology Reveals a High Environmental and Metabolic Plasticity as a Successful Evolutionary Strategy in a Long-Lived Homeostatic Triassic Temnospondyl". Evolutionary Biology. 40 (4): 627–647. doi:10.1007/s11692-013-9238-3. ISSN 0071-3260. PMC 3832766. PMID 24293739.
11. Schoch, Rainer R.; Milner, Andrew R. (2014). Sues, Hans-Dieter (ed.). Handbuch der Paläoherpetologie, Part 3A2. Temnospondyli I. Stuttgart. ISBN 978-3-931516-26-0. OCLC 580976.