Geologic Time Scale: Triassic Period
(251.902 to 201.36 million years ago)
The Triassic Period is the first and shortest period of the Mesozoic Era. Both the start (Permian-Triassic) and end (Triassic-Jurassic)of the period are marked by major extinction events. Triassic Period (Greek “triad” meaning three) was named in 1834 by Friedrich August von Alberti () after the a succession of three district rock layers that are widespread in southern Germany: the lower Bruntsandstein (colorful sandstone), the middle Muschelkalk (shell-bearing limestone), and the upper Keuper (colored clay).
During the Triassic, almost all the Earth’s land mass was concentrated in to a single supercontinent, Pangaea (meaning ‘entire land’) more or less centered on the equator and extended between the poles. New modern types of coral appear forming small reef patches, while cephalopods called ammonites recovered, diversifying from a single line that survived the Permian extinction during the Triassic.We also see the introduction of the first dinosaurs, marine reptiles, pterosaurs, and true mammals.