Plagiosauridae

Plagiosauridae
	Gerrothorax fossil in the State Museum for Natural History Stuttgart
Temporal occurrence
	Triad
	251.2 to 201.3 million years
Locations
	Europe; Kazakhstan; Spitsbergen; Thailand; Australia;
Systematics
	Vertebrates (vertebrata)
	Land vertebrates (Tetrapoda)
	Temnospondyli
	Trematosauria
	Plagiosauroidea
	Plagiosauridae
Scientific name
	Plagiosauridae
	Abel , 1919

The Plagiosauridae are a family of amphibian-like animals from the group of Temnospondyles that lived in fresh and brackish water. Fossils dated to the Middle and Upper Triassic come from Europe and Asia. A single fund is from the Lower Triassic ( Olenekian ) of Australia before ( Plagiobatrachus australis ).

Skull of plagiosternum

Skull of Plagiosuchus

features

Plagiosaurs usually reached a length of one to two meters (a maximum of 2.5 m) and had unusually wide and flattened bodies that were only a few inches high even in two-meter-long specimens. Seen from above, the skulls were parabolically rounded in front and often much wider than they were long. The orbits were huge and probably took up strong muscles next to the eyes , similar to those of recent tail amphibians. The skull bones were largely reduced in some species and the skull was dominated by the huge eye-muscle windows. On the underside of the skull there are often bone rods of the gill skeleton. Deep grooves on their rear edges indicate blood vessels supplying the gills. Plagiosaurs lived purely aquatic and had internal gills, similar to the bony fish. Their limbs were short and weak, and their shoulder and pelvic girdles were redesigned to allow the animals to remain flat. The fuselage was armored by small, tile-like, superimposed bone plates . They were characterized by fine pustules on their upper side. The trunk armor could have completely enclosed the body (e.g. in the case of a gerrothorax ) or only formed a row of plates over the spine (in the case of Plagiosuchus ). Because of their weak limbs, it is assumed that the plagiosaurs, similar to today's flatfish , inhabited the bottom of the water as ambulance hunters.

Genera

literature

Rainer Schorch: Plagiosaurs: bizarre predators in Triassic swamps and lagoons. In Fossils, Journal of Earth History. Issue 3/2014 May / June, Volume 31, ISSN 0175-5021 .

Web links

Commons : Plagiosauridae - collection of images, videos and audio files

Plagiosauridae Abel 1919 in the Paleobiology Database
Plagiosauridae near Palaeos