Carnian

The Carnian is a special time from long ago, during the Upper Triassic Series. It lasted from about 237 to 227.3 million years ago (Ma). This time came after the Ladinian and before the Norian.

During the Carnian, the climate changed a lot. There was much more rain, called the Carnian pluvial episode. This rainy time changed many plants and animals.

At the end of the Carnian, when it changed into the Norian, the world of living things changed too. These changes helped shape our world today.

Stratigraphic definitions

The Carnian was named in 1869 by Edmund von Mojsisovics. It may have been named after the Carnic Alps, the Austrian region of Carinthia, or the Carnia historical region in northeastern Italy. The name refers to a part of the Hallstatt Limestone in Austria.

The start of the Carnian Stage is marked by the first appearance of the ammonite species Daxatina canadensis. The global reference point for this is located near Badia in the Val Badia region of South Tyrol, Italy.

Paleogeography and climate

The Carnian period had a geography much like the rest of the Triassic era. Most landmasses were joined together in a giant supercontinent called Pangaea, with one huge ocean named Panthalassa. This ocean had a western part called Paleo-Tethys, and its rocks can now be found in places like southeastern Europe, the Middle East, the Himalayas, and even as far as the island of Timor.

During this time, there were no polar ice caps, and the climate was dry in warm areas. However, there was a time when the tropical regions became much wetter. This period is known as the "Carnian Pluvial Event", happening between the later part of early Carnian and the start of late Carnian.

Carnian life

Main page: Category:Carnian life

The Carnian was an important time for life in the oceans and on land. In the seas, tiny shelled creatures called calcareous nanoplankton appeared for the first time, including a group called coccolithophores.

Many interesting animals lived during this time. In the oceans, special kinds of mollusks called ammonoids, such as the genus Trachyceras, appeared. Also, bivalves like Halobia lived on the deep sea floor. For the first time, modern-looking coral reefs made of scleractinian corals became more common.

On land, this was a key time for the first true dinosaurs. Dinosaurs like Herrerasaurus and Eoraptor lived during the Carnian, along with other early archosaurs such as phytosaurs, rhynchosaurs, aetosaurs, and rauisuchians. Though these dinosaurs were small at first, they would later become the dominant land animals for millions of years. Meanwhile, the ancestors of mammals, known as therapsids, became less common and smaller in size.

Classic localities and Lagerstätten

The lower Carnian time period, about 237 to 227.3 million years ago, has many important places where scientists found fossils. One famous place is the San Cassiano Formation in the Dolomites of northern Italy. Many fossils have been found around the town of Cortina d'Ampezzo and near San Cassiano village. These fossils include many types of sea creatures like ammonoids, snails, clams, and corals.

Another important place is the Ischigualasto Formation in northwestern Argentina, which has some of the oldest known dinosaurs. The Madygen Formation in Kyrgyzstan has given scientists over 20,000 fossils of insects, animals, and plants.

Notable Formations

• Chañares Formation (Argentina)
• Denmark Hill Insect Bed (Queensland, Australia)
• Ischigualasto Formation (Argentina)
• Los Rastros Formation (Argentina)
• Lower Maleri Formation (Telangana, India)
• Molteno Formation (South Africa)
• Potrerillos Formation (Argentina)
• Santa Maria Formation (Rio Grande do Sul, Brazil)
• Stuttgart Formation (Germany)
• Tiki Formation (Madhya Pradesh, India)
• Xiaowa Formation / Wayao Member of the Falang Formation (Guizhou and Yunnan, China)
• Zhuganpo Formation / Zhuganpo Member of the Falang Formation (late Ladinian - early Carnian) (Guizhou and Yunnan, China)