Norian
| System/ Period |
Series/ Epoch |
Stage/ Age |
Age (Ma) | |
|---|---|---|---|---|
| Jurassic | Lower/ Early |
Hettangian | younger | |
| Triassic | Upper/ Late |
Rhaetian | 201.3–208.5 | |
| Norian | 208.5–~228 | |||
| Carnian | ~228–~235 | |||
| Mid/ Middle |
Ladinian | ~235–~242 | ||
| Anisian | ~242–247.2 | |||
| Lower/ Early |
Olenekian | 247.2–251.2 | ||
| Induan | 251.2–252.2 | |||
| Permian | Lopingian | Changhsingian | older | |
| Subdivision of the Triassic system according to the IUGS, as of July 2012. |
||||
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 ~228 to ~208.5 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
Dinosaurs
| Dinosaurs of the Norian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| 208 Ma | Avon, England | A disputed dinosaur known from an ilium, maxilla, astragalus, and humerus (it could be a chimera). Agnosphitys lies close to the ancestry of dinosaurs, although exactly where is disputed by researchers. Some consider it a saurischian close to the beginnings of dinosaur evolution, while others consider it a non-dinosaurian dinosauromorph. | ||
| Carnian to Norian | Chinle Formation, New Mexico, USA | |||
| 210 Ma | South Africa | A swift-running basal ornithischian that has the most complete known remains from any Triassic ornithischian, shedding new light on the origin of this group. One of the earliest known ornithischians, it sheds some light on early dinosaur relationships because early dinosaurs are known from mostly incomplete skeletons. Eocursor is known from partial skeletal elements, including skull fragments, spinal elements, pelvis, long leg bones, and unusually large grasping hands. | ||
| 228-201.3 Ma, Norian to Rhaetian | Trossingen Formation, Thuringia, Germany | A coelophysoid that is the best represented Triassic theropod from Europe and one of the largest known. | ||
| 214-204 Ma, Carnian to Norian | Trossingen Formation, Bavaria, Germany | |||
| Norian to Rhaetian | ||||
†Pterosaurs
| Pterosaurs of the Norian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
Crocodylomorphs
| Crocodylomorphs of the Norian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
†Ichthyosaurs
| Ichthyosaurs of the Norian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
|
Nevada, USA | |||
†Dinosauromorphs (non-dinosaurian)
| †Non-dinosaurian dinosauromorphs of the Norian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| New Mexico | ||||
†Placodonts
| Placodonts of the Norian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
†Crurotarsans (non-crocodylomorph)
| †Non-crocodylomorph Crurotarsans of the Norian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Lesotho | ||||
Mammalia
| Mammalia[3] of the Norian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Norian to Sinemurian | Greenland and Western Europe | A Late Triassic-Early Jurassic symmetrodontan. | ||
Temnospondyls
| †Temnospondyls of the Norian | ||||
|---|---|---|---|---|
| Taxa | Presence | Location | Description | Images |
| Arizona | ||||
| Arizona | ||||
†Ammonites
References
Notes
- ↑ According to Gradstein et al. (2004). Brack et al. (2005) give 226 to 207 million years
- ↑ See for a detailed geologic timescale Gradstein et al. (2004)
- ↑ The genera listed are included in Mammalia by Kielan-Jaworowska et al. (2004) but not by those who restrict the taxon to the crown group.
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.
- Kielan-Jaworowska, Z.; Cifelli, R. L.; Luo, Zhe-Xi; 2004: Mammals from the Age of Dinosaurs, Columbia University Press.
- Martz, J.W.; 2008: Lithostratigraphy, chemostratigraphy, and vertebrate biostratigraphy of the Dockum Group (Upper Triassic), of southern Garza County, West Texas, Doctoral Dissertation, Texas Tech.
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]
| Triassic Period | ||
|---|---|---|
| Lower/Early Triassic | Middle Triassic | Upper/Late Triassic |
| Induan |Olenekian | Anisian | Ladinian | Carnian | Norian Rhaetian |
