The Exter Formation is the only formation of the Upper

Keuper The Keuper is a lithostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of west and central Europe. The Keuper consists of dolomite, shales or claystones and evaporites that were deposited during the Middle and Late ...

or Rhätsandstein, and is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. It preserves

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

dating back to the

Rhaetian The Rhaetian is the latest age of the Triassic Period (in geochronology) or the uppermost stage of the Triassic System (in chronostratigraphy). It was preceded by the Norian and succeeded by the Hettangian (the lowermost stage or earliest age ...

of the

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

period (specifically around 205 Ma).Exter Formation
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.orgRhätkeuper
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Fossil content

The formation has provided fossils of:

Mammals

* '' Thomasia antiqua'' * Haramiyidae indet.

Therapsids

* '' Chalepotherium plieningeri''

Reptiles

* '' "Ichthyosaurus" rhaeticus'' * '' Megalosaurus cloacinus'' * '' Nothosaurus cloacinus'' * '' Phytosaurus cubicodon''? * '' Phytosaurus cylindricodon''? * '' Plateosaurus ornatus'' * ''

Rhaeticosaurus mertensi ''Rhaeticosaurus'' (meaning 'Rhaetian lizard') is an extinct genus of basal pliosauroidea, pliosauroid from the Late Triassic (Rhaetian) rocks of the Exter Formation. The type and only species, ''Rhaeticosaurus mertensi'', was named by Tanja Win ...

''Wintrich et al., 2017 * '' Termatosaurus albertii'' * '' Termatosaurus crocodilinus'' * '' Plateosaurus sp.''Fraas, 1897 * Plesiosauria indet.