Temnospondyli

Eryops, live reconstruction

• Worldwide

The Temnospondyli ( altgr. τέμνειν temnein cut, ' and σπόνδυλος spondylos, eddy ') are a taxon of a very different nature, small to very large non- amniotic land vertebrates, which lived during the Carboniferous, Permian and Triassic world. Some forms lived up to the Lower Cretaceous. The animals lived fully aquatic freshwater, amphibious or terrestrial, a group living in the coastal sea (marine ). Their fossils have been found on all continents. It is discussed whether, under the Temnospondyli the ancestors of modern amphibians are found, or if they have died without descendants.

History of development

During the Carboniferous, there were original, medium-sized ( Dendrerpeton ) or large ( Cochleosaurus, about 1.5 meters long ) semiaquatic forms. Other, more advanced genera such Limnerpeton, were small and resembled today's newts. Branchiosaurus and his relatives kept her life their external gills and resembled the modern axolotl.

While the upper Carboniferous and early Permian developed different groups a stronger spine and stronger legs. They adapted to the life ashore ( Cacops ) or lived semi -aquatic as big, clumsy predators ( Trematops, Eryops ).

Archegosaurus had a long snout and, although he was not armored, very similar to today's crocodiles.

Among the relatives of this group also includes Prionosuchus from Brazil, which was the largest non- amniotic land vertebrate with a length of 9 meters.

During the late Permian terrestrial forms died out due to the increasing drought and competition from the Reptiles, but exclusively in the water and the amphibious living forms lived on, including Melosaurus from Eastern Europe.

Some of the Temnospondyli who lived in the lakes and rivers of the Late Permian to the permanent aquatic life adapted to more and more. The vertebrae were weak legs, small and rudimentary, the heavy skull was large and flat, with upturned eyes. These species are the classic Stereospondyli and related species. During the Triassic these animals dominated the freshwater ecosystems and developed into small and large forms. During the early Triassic, a group langschnäuziger fish eaters, the Trematosaurier, even the marine life is adapted to.

The Capitosauroidea consisted of medium-sized and large forms, with lengths from 2.3 to 4 meters, for example, Paracyclotosaurus and Cyclotosaurus. The largest genus Mastodonsaurus had an extremely large, over a meter long, flat skull. Probably these animals spent most of their lives or at the water bottom. Their prey they caught by sudden lifting of her upper jaw. Smaller amphibians and fish have been sucked into the mouth.

In the Late Triassic lived superficially very similar, up to 1.5 meters long Metoposauridae and the strange, over a meter long and broad-headed Plagiosaurier who had external gills.

The mass extinction about 200 million years ago at the end of the Triassic, only two survived groups from Gondwana, the Brachyopidae and Chigutisauridae. Both groups made ​​during the following Jura large growing forms out, the Brachyopidae in China and the Chigutisauridae in Gondwana.

The youngest known Temnospondyle was Koolasuchus from the middle Cretaceous of Australia. He probably lived in the lakes of a grave breach, where the winters were so cold that potentially competing crocodiles avoided the habitat. With a length of 5 meters, he was one of the greatest representatives of this group.

System

• Temnospondyli ( Batrachomorpha ) Limnarchia Divinosauria
• Stereospondyli Trematosauria
• Capitosauria

• Dendrerpetontidae
• Euskelia Eryopidae
• Dissorophoidea, unnamed monophyletic in Benton 2007 Dissorophidae
• Untitled monophyletic Branchiosauridae
• Amphibamidae
• Lissamphibia ( extant amphibians)