| System (period) | Series (epoch) | Stage (age) | Lower boundary, Ma | |
|---|---|---|---|---|
| Jurassic | Lower | Hettangian | 201.4±0.2 | |
| Triassic | Upper (Late) | Rhaetian | ~208.5 | |
| Norian | ~227 | |||
| Carnian |  ~237
| |||
| Middle | Ladinian | ~242
| ||
| Anisian | 247.2 | |||
| Lower (Early) | Olenekian | 251.2 | ||
| Induan | 251.902±0.024
| |||
| Permian | Lopingian | Changhsingian | older | |
| Subdivisions and "golden spikes" according to IUGS as of September 2023[1] | ||||
Alluvial plain red clays of the Travenanzes formation, upper Carnian, the Dolomites, northern Italy
The Carnian (less commonly, Karnian) is the lowermost stage of the Upper Triassic series (or earliest age of the Late Triassic epoch). It lasted from ~237 to ~227 million years ago (Ma). The Carnian is preceded by the Ladinian and is followed by the Norian. Its boundaries are not characterized by major extinctions or biotic turnovers, but a climatic event (known as the Carnian Pluvial Event) occurred during the Carnian and seems to be associated with important extinctions or biotic radiations. The last miomopteran insects are known from this stage.
It includes Julian and Tuvalian substages.
Definition[]
The GSSP of the Carnian stage was ratified in 2008. The lower boundary is fixed in base of marly limestone bed SW4 in Dolomites, Italy, and related to the first appearance of the ammonoid Daxatina canadensis.[2]
Carnian life[]
Insects were one of the most numerous or the most numerous group of arthropods. However, miomopterans, an order that arose in the Late Pennsylvanian (late Carboniferous), were on the verge of extinction. Miomina, the latest member, is known from Los Rastros Formation in Argentina. Other insects of the time include cockroaches (Lariojablatta, Condorblatta), hemipterans (Saaloscytina) and beetles (Argentinocupes, Argentinosyne).
Rivers and lakes continued to be inhabited by large temnospondyls like Metoposaurus, but phytosaurs like Parasuchus and long-snouted Ebrachosuchus were already competing with them, occupying the same ecological niche. Being reptiles, phytosaurs were better able to withstand the lack of water due to their dense skin. Herbivorous rhynchosaurids like Hyperodapedon used their beaks for cutting plants. Dicynodonts like Placerias, Ischigualastia and Moghreberia, dug up plant roots using tusks. The dominant land predators of that time were pseudosuchian rauisuchids like the huge Tikisuchus from the Carnian strata of Tiki Formation in India. Small lizard-like reptiles Kuehneosaurus glided using "wings" formed from ribs. Specimens of indeterminate Kuehneosaurus species were found in the Carnian strata of England and Wales.
The earliest undoubted dinosaurs are known from the Carnian. Most of them like Staurikosaurus, Buriolestes, Panphagia and Eoraptor, were found in South America. Mbiresaurus, an early sauropodomoph, lived in what is now Zimbabwe (Africa). During Carnian, these regions were not separated by ocean since the most of land was concentrated in the supercontinent of Pangaea.
References[]
- ↑ "Latest version of international chronostratigraphic chart". International Commission on Stratigraphy. https://stratigraphy.org/chart#latest-version.
- ↑ "GSSP Table - Mesozoic Era". https://timescalefoundation.org/gssp/index.php?parentid=35.