Norian

The Norian is a division of the Triassic geological period. It has the rank of an age (geochronology) or stage (chronostratigraphy). The Norian lasted from 216.5 ± 2.0 to 203.6 ± 1.5 million years ago.^[1] It was preceded by the Carnian and succeeded by the Rhaetian.^[2]

Stratigraphic definitions

The Norian was named after the Noric Alps in Austria. The stage was introduced into scientific literature by Austrian geologist Edmund Mojsisovics von Mojsvar in 1869.

The Norian stage begins at the base of the ammonite biozones of Klamathites macrolobatus and Stikinoceras kerri, and at the base of the conodont biozones of Metapolygnathus communisti and Metapolygnathus primitius. A global reference profile for the base (a GSSP) had in 2009 not yet been appointed.

The top of the Norian (the base of the Rhaetian) is at the first appearance of ammonite species Cochloceras amoenum. The base of the Rheatian is also close to the first appearance of conodont species Misikella spp. and Epigondolella mosheri and the radiolarid species Proparvicingula moniliformis.

In the Tethys domain, the Norian stage contains six ammonite biozones:

• zone of Halorites macer
• zone of Himavatites hogarti
• zone of Cyrtopleurites bicrenatus
• zone of Juvavites magnus
• zone of Malayites paulckei
• zone of Guembelites jandianus

Palaeontology

• Synapsids
• Aetosaurs
• Dicynodonts
• Phytosaurs

Dinosaurs

Dinosaurs of the Norian
Taxa	Presence	Location	Description	Images
Agnosphitys				Coelophysis Liliensternus Plateosaurus Sellosaurus Thecodontosaurus
Coelophysis	Late Carnian to early Norian	Ghost Ranch, New Mexico, USA
Halticosaurus
Liliensternus
Plateosaurus
Sellosaurus
Thecodontosaurus	Norian/Rhaetian

Pterosaurs

Pterosaurs of the Norian
Taxa	Presence	Location	Description	Images
Eudimorphodon				Eudimorphodon Preondactylus
Peteinosaurus
Preondactylus

Crocodylomorphs

Crocodylomorphs of the Norian
Taxa	Presence	Location	Description	Images
Saltoposuchus				Saltoposuchus

Ichthyosaurs

Ichthyosaurs of the Norian
Taxa	Presence	Location	Description	Images
Shonisaurus Shonisaurus popularis				Shonisaurus

Dinosauromorphs (non-dinosaurian)

†Non-dinosaurian dinosauromorphs of the Norian
Taxa	Presence	Location	Description	Images
Dromomeron				Dromomeron
Eucoelophysis		New Mexico

Placodonts

Placodonts of the Norian
Taxa	Presence	Location	Description	Images
Psephoderma				Psephoderma

Crurotarsans (non-crocodylomorph)

†Non-crocodylomorph Crurotarsans of the Carnian
Taxa	Presence	Location	Description	Images
Basutodon				Teratosaurus
Teratosaurus

Mammaliaformes

Ammonites

• Acanthinites

References

Notes

Literature

• Brack, P.; Rieber, H.; Nicora, A. & Mundil, R.; 2005: The Global boundary Stratotype Section and Point (GSSP) of the Ladinian Stage (Middle Triassic) at Bagolino (Southern Alps, Northern Italy) and its implications for the Triassic time scale, Episodes 28(4), pp. 233-244.
• Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.

External links

• GeoWhen Database - Norian
• Upper Triassic timescale, at the website of the subcommission for stratigraphic information of the ICS
• Norges Network of offshore records of geology and stratigraphy: Stratigraphic charts for the Triassic, [1] and [2]