(round eared lizard).
Named By: Eberhard Fraas - 1889.
Synonyms: Mastodonsaurus robustus.
Classification: Chordata, Amphibia, Temnospondyli, Mastodonsauridae.
Species: C. robustus (type), C. buechneri, C. ebrachensis, C. hemprichi, C. mordax, C. naraserluki, C. papilio, C.posthumus.
Size: Skulls up to 70 centimetres long, largest individuals up to 4.3 meters long.
Known locations: England - Bromsgrove Sandstone Formation (Finstall Member). Germany - Hassberge Formation, Löwenstein Formation, Stuttgart Formation, Trossingen Formation. Greenland (Ørsted Dal Member) - Fleming Fjord Formation. Luxembourg. Poland - Drawno Beds Formation. Russia - Bukobay Formation. Thailand - Huai Hin Lat Formation.
Time period: Ladinisan to Norian of the Triassic.
Fossil representation: Many individuals.
By the end of the Triassic, the temnospondyl amphibians had already been greatly reduced in number to what they were in the earlier Permian and Carboniferous. They were not all gone however, and some like Cyclotosaurus were without doubt flourishing. So far fossils of Cyclotosaurus have been found all the way from Greenland, across much of Europe, and even as far as Thailand in south East Asia. On top of this the largest individuals of Cyclotosaurus grew to over four meters long, meaning that large Cyclotosaurus were even capable of taking down early dinosaurs. The dentition of Cyclotosaurus however indicates a more piscivorous (fish hunting lifestyle), though Cyclotosaurus could have still snatched smaller animals from the water’s edge.
- Cyclotosaurus cf. Posthumus Fraas (Capitosauridae, Stereospondyli) from the Huai Hin Lat Formation (Upper Triassic), Northeastern Thailand. - Geobios 14 (6): 711–25. - Rucha Ingavat & Phillippe Janvier - 1981.
- Late Triassic continental vertebrates and depositional environments of the Fleming Fjord Formation, Jameson Land, East Greenland. - Meddelelser om Grønland, Geoscience 32: 1–25. - F. A. Jenkins Jr, N. H. Shubin, W. W. Amaral, S. M. Gatesy, C. R. Schaff, L. B. Clemmensen, W. R. Downs, A. R. Davidson, N. Bonde & F. Osbaeck - 1994.
- The temnospondyl amphibian Cyclotosaurus from the Upper Triassic of Poland. - Palaeontology 48: 157–70. - T. Sulej & D. majer - 2005.
- A new species of Cyclotosaurus (Stereospondyli, Capitosauria) from the Late Triassic of Bielefeld, NW Germany, and the intrarelationships of the genus. - Fossil Record. 19 (2): 83–100. - F. Witzmann, S. Sachs & C. J. Nyhuis - 2016.
- Cyclotosaurus naraserluki, sp. nov., a new Late Triassic cyclotosaurid (Amphibia, Temnospondyli) from the Fleming Fjord Formation of the Jameson Land Basin (East Greenland). - Journal of Vertebrate Paleontology. e1303501. - M. Marzola, O. Mateus, N. H. Shubin & L. B. Clemmensen - 2017.