| Plagiosuchus Temporal range: Triassic, | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Amphibia |
| 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.
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.
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]
Temnospondyli or temnospondyls is a diverse ancient order of small to giant tetrapods — often considered primitive amphibians — that flourished worldwide during the Carboniferous, Permian and Triassic periods, with fossils being found on every continent. A few species continued into the Jurassic and Early Cretaceous periods, but all had gone extinct by the Late Cretaceous. During about 210 million years of evolutionary history, they adapted to a wide range of habitats, including freshwater, terrestrial, and even coastal marine environments. Their life history is well understood, with fossils known from the larval stage, metamorphosis, and maturity. Most temnospondyls were semiaquatic, although some were almost fully terrestrial, returning to the water only to breed. These temnospondyls were some of the first vertebrates fully adapted to life on land. Although temnospondyls are amphibians, many had characteristics such as scales and armour-like bony plates that distinguish them from the modern soft-bodied lissamphibians.
Gerrothorax is an extinct genus of temnospondyl amphibian from the Triassic period of Greenland, Germany, Poland, Sweden, and possibly Thailand. It is known from a single species, G. pulcherrimus, although several other species such as G. pustuloglomeratus have been named in the past.
Mastodonsaurus is an extinct genus of temnospondyl amphibian from the Middle Triassic of Europe. It belongs to a Triassic group of temnospondyls called Capitosauria, characterized by their large body size and presumably aquatic lifestyles. Mastodonsaurus remains one of the largest amphibians known, and may have exceeded 6 meters in length.
Metoposaurus meaning "front lizard" is an extinct genus of stereospondyl temnospondyl amphibian, known from the Late Triassic of Germany, Italy, Poland, and Portugal. This mostly aquatic animal possessed small, weak limbs, sharp teeth, and a large, flat head. This highly flattened creature mainly fed on fish, which it captured with its wide jaws lined with needle-like teeth. Many Metoposaurus mass graves have been found, probably from creatures that grouped together in drying pools during drought.
The Stereospondyli are a group of extinct temnospondyl amphibians that existed primarily during the Mesozoic period. They are known from all seven continents and were common components of many Triassic ecosystems, likely filling a similar ecological niche to modern crocodilians prior to the diversification of pseudosuchian archosaurs.
Cyclotosaurus is an extinct genus of temnospondyl within the family Mastodonsauridae. It was of great size for an amphibian, had an elongated skull up to 56 cm (22 in).
Sclerothorax is an extinct genus of temnospondyl amphibian from the Early Triassic of Germany. It is distinguished from other temnospondyls by its short and very wide skull and the elongated neural spines that form a ridge along its back. Sclerothorax is a basal member of Capitosauria, a large clade of temnospondyls that lived throughout the Triassic.
Cheliderpeton is an extinct genus of temnospondyl amphibian. It lived during the Early Permian in what is now Europe. Fossils have been found from the Ruprechtice horizon of the Intrasudetic Basin of Bohemia in the Czech Republic, as well as the Saar-Nahe Basin of southwestern Germany. Cheliderpeton had a 16 cm skull, and reached about 65 cm in length.
Trematosaurus is an extinct genus of trematosaurid temnospondyl amphibian found in Germany and Russia. It was first named by Hermann Burmeister in 1849 and the type species is Trematosaurus brauni.
Actinodon is an extinct genus of eryopoidean temnospondyl within the family Eryopidae.
Plagiosauridae is a clade of temnospondyl amphibians of the Middle to Late Triassic. Deposits of the group are most commonly found in non-marine aquatic depositional environments from central Europe and Greenland, but other remains have been found in Russia, Scandinavia, and possibly Thailand.
Mastodonsauridae is a family of capitosauroid temnospondyls. Fossils belonging to this family have been found in North America, Greenland, Europe, Asia, and Australia. The family Capitosauridae is synonymous with Mastodonsauridae.
Stereospondylomorpha is a clade of temnospondyls. It includes the superfamily Archegosauroidea and the more diverse group Stereospondyli. Stereospondylomorpha was first proposed by Yates and Warren (2000), who found Archegosauroidea and Stereospondyli to be sister taxa in their phylogenetic analysis. A similar clade is Archegosauriformes, named by Schoch and Milner (2000), which includes Stereospondyli and some Permian temnospondyls that are similar in appearance to stereospondyls, including the archegosauroids. However, according to Schoch and Milner's phylogeny, Archegosauroidea is a paraphyletic group of taxa that are successively basal to Stereospondyli, rather than a monophyletic sister taxon.
Hyperokynodon is an extinct genus of trematosaurian temnospondyl within the family Trematosauridae. Fossils have been found in Germany. While most trematosaurids existed during the Early Triassic, Hyperokynodon has been found in Late Triassic deposits, making it the youngest known trematosaurid. Hyperokynodon was known since 1852, but it was not identified as a trematosaurid until 1987. The type and only species is H. keuperinus.
Stanocephalosaurus is an extinct genus of large-sized temnospondyl amphibians living through the early to mid Triassic. The etymology of its name most likely came from its long narrow skull when compared to other temnospondyls. Stanocephalosaurus lived an aquatic lifestyle, with some species even living in salt lakes. There are currently three recognized species and another that needs further material to establish its legitimacy. The three known species are Stanocephalosaurus pronus from the Middle Triassic in Tanzania, Stanocephalosaurus amenasensis from the Lower Triassic in Algeria, and Stanocephalosaurus birdi, from the middle Triassic in Arizona. Stanocephalosaurus rajareddyi from the Middle Triassic in central India needs further evidence in order to establish its relationship among other Stanocephalosaurs. Like other temnospondyls, Stanocephalosaurus was an aquatic carnivore. Evidence of multiple species discovered in a wide range of localities proves that Stanocephalosaurus were present all across Pangea throughout the early to mid Triassic.
Acanthostomatops is an extinct genus of zatracheidid temnospondyl from the Lower Permian Döhlen Basin of Saxony.
Branchiosauridae is an extinct family of small amphibamiform temnospondyls with external gills and an overall juvenile appearance. The family has been characterized by hundreds of well-preserved specimens from the Permo-Carboniferous of Middle Europe. Specimens represent well defined ontogenetic stages and thus the taxon has been described to display paedomorphy (perennibranchiate). However, more recent work has revealed branchiosaurid taxa that display metamorphosing trajectories. The name Branchiosauridae refers to the retention of gills.
The Erfurt Formation, also known as the Lower Keuper, is a stratigraphic formation of the Keuper group and the Germanic Trias supergroup. It was deposited during the Ladinian stage of the Triassic period. It lies above the Upper Muschelkalk and below the Middle Keuper.
Megalophthalma is an extinct genus of temnospondyl amphibian belonging to the family Plagiosauridae. It is represented by the single type species Megalophthalma ockerti from the Middle Triassic Erfurt Formation in southern Germany, which is itself based on a single partial skull and a fragment of the lower jaw. Megalophthalma is distinguished from other temnospondyls by its very large orbits or eye sockets, which occupy most of the skull and are bordered by thin struts of bone. Like those of most plagiosaurids, the skull flat, wide, and roughly triangular. The orbits are pentagon-shaped. The bones at the back of the skull are highly modified and show similarities with those of the plagiosaurid Plagiosternum. Both Megalophthalma and Plagiosternum lack prefrontal and postfrontal bones. In fact, Megalophthalma and Plagiosternum are thought to form their own clade or evolutionary grouping within Plagiosauridae called Plagiosterninae. In overall form Megalophthalma and Plagiosternum are intermediate between the basal plagiosaurid Plagiosuchus and the derived Gerrothorax.
The Stuttgart Formation is a geologic formation in Germany. It preserves fossils dating back to the Carnian stage of the Triassic period.
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