Trematosauria

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Trematosauria
Skeletal reconstruction of Koskinonodon

Skeletal reconstruction of Koskinonodon

Temporal occurrence
Lower Triassic to Lower Cretaceous
251.9 to 100.5 million years
Locations
  • Worldwide
Systematics
Chordates (chordata)
Vertebrates (vertebrata)
Land vertebrates (Tetrapoda)
Temnospondyli
Trematosauria
Scientific name
Trematosauria
Romer , 1947

The Trematosauria are an extinct group of terrestrial vertebrates from the Temnospondyli group . They lived from the Lower Triassic to the Lower Cretaceous (251.9 to 100.5 mya ). Their ancestors are among the few Temnospondyli who survived the mass extinction at the end of the Permian .

Most of the Trematosauria - there are several lineages - lived aquatic . The deposits in which the fossils of some forms were found suggest that some lived in the sea. The Trematosauria are the only amphibian-like animals that immigrated to this habitat besides tulip pebbles .

Several lines of Trematosauria have been described:

Trematosauroidea

Trematosaurus

The typical member of the Trematosauroidea was a gavial - like long- snouted animal that specialized in fishing.

They had distinct sideline canals on the skull . Fossil remains of the animals have been found in Greenland, Svalbard, Madagascar, South Africa, western North America, Australia and Russia. They lived only in the Lower Triassic and are likely a primitive line of the Trematosauria.

Metoposauroidea

Gerrothorax

The Metoposauroidea were flat-headed, aquatic animals and resembled the Capitosauria . They differed from these by the eyes that were further forward and directed upwards. The Metoposauroidea were particularly common in the Upper Triassic in North America, Europe and India, but already lived in the Middle Triassic and possibly had a worldwide distribution. The animals may have spent most of the time immobile, waiting for prey to swim past. There were rows of teeth in their jaws and they also had large teeth on the palatine bone . On land they were probably very awkward. Large amounts of fossilized fossils were found particularly in deposits formed from the mud of shallow, drying freshwater lakes.

Plagiosauroidea

Metoposaurus

The Plagiosauroidea are only known from rare fossils from the entire Triassic of Europe. They are strange temnospondyles with very short, wide skulls that were covered by pustule-like outgrowths and reduced limbs. The eyes sat close together on the center of the skull. They lived aquatic. Some forms, e.g. B. Gerrothorax retained their external gills even as adults.

Brachyopoidea

Batrachosuchus

The brachyopoidea had a short, wide, and flat skull. They probably lived semiaquatically. Fossils have been found in North and South America, Australia, Asia, South Africa, Europe and the Antarctic. They lived even longer during the entire Triassic, the families Brachyopidae and Chigutisauridae . In Australia, China and Mongolia very large forms from the Lower, Middle and Upper Jurassic were found. The Koolasuchus from the Lower Cretaceous of Australia, described in 1997, was the last living member of the Temnospondyli. The late forms likely survived in regions that were geographically isolated or had a cool climate so they were not colonized by crocodiles .

literature

Individual evidence

  1. ↑ Palæos Trematosauroidea
  2. ↑ Palæos Metoposauroidea
  3. ↑ Palæos Plagiosauroidea
  4. ↑ Palæos Brachyopoidea ( Memento from October 15, 2010 in the Internet Archive )

Web links

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