The Late Triassic (also known as Upper Triassic, or Keuper) is the third and final of three epochs of the Triassicperiod. It spans the time between 228 ± 2 Ma and 199.6 ± 0.6 Ma (million years ago). The Late Triassic is divided into the Carnian, Norian and Rhaetianfaunal stages. The word epoch can mean either an interval of time, or a particular point in time used as a reference point. ... The Triassic is a geologic period that extends from about 245 to 202 million years ago (mya). ... The table and timeline of geologic periods presented here is in accordance with the dates and nomenclature proposed by the International Commission on Stratigraphy. ... Mega-annum, usually abbreviated as Ma, is a unit of time equal to one million years. ... Jump to: navigation, search The Carnian is a stage on the geologic time scale occuring from 228 +/- 2 to 216. ... Jump to: navigation, search The Norian Stage was a portion of the Triassic geological period. ... Jump to: navigation, search The Rhaetian Stage is the most recent stage of the Late Triassic. ... Faunal stages are a subdivision of geologic time used primarily by paleontologists who study fossils rather than by geologists who study rock formations. ...
The Triassic was named in 1834 by Friedrich Von Alberti from the three distinct layers—redbeds, capped by chalk, followed by fl shales— that are found throughout Germany and Northwest Europe, called the 'Trias'.
The Crurotarsi were the other important archosaur clade, and during the LateTriassic these also reached the height of their diversity, with various groups including the Phytosaurs, Aetosaurs, several distinct lineages of Rauisuchia, and the first crocodylians (the Sphenosuchia).
The Triassic period ended with a mass extinction, which was particularly severe in the oceans; the conodonts disappeared, and all the marine reptiles except ichthyosaurs and plesiosaurs.
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