Middle Triassic

Second epoch of the Triassic period From Wikipedia, the free encyclopedia

In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided in chronostratigraphy. The Middle Triassic spans the time between 246.7 Ma and 237 Ma (million years ago). It is preceded by the Early Triassic Epoch and followed by the Late Triassic Epoch. The Middle Triassic is divided into the Anisian and Ladinian ages or stages.[7]

Name formalityFormal
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Quick facts Chronology, Etymology ...
Middle Triassic
246.7 – ~237 Ma
A map of Earth as it appeared 240 million years ago during the Middle Triassic Epoch, Ladinian Age
Middle Triassic aged Muschelkalk (Schaumkalk) in Baden-Württemberg, Germany
Chronology
255 
250 
245 
240 
235 
230 
225 
220 
215 
210 
205 
200 
Pz
 
 
 
Scleractinian
corals & calcified sponges[1]
Coals return[2]
Full recovery of woody trees[3]
Subdivision of the Triassic according to the ICS, as of 2024.[5]
Vertical axis scale: Millions of years ago
Etymology
Name formalityFormal
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitEpoch
Stratigraphic unitSeries
Time span formalityFormal
Lower boundary definitionNot formally defined
Lower boundary definition candidates
Lower boundary GSSP candidate section(s)
Upper boundary definitionFAD of the Ammonite Daxatina canadensis
Upper boundary GSSPPrati di Stuores, Dolomites, Italy
46.5269°N 11.9303°E / 46.5269; 11.9303
Upper GSSP ratified2008[6]
Close

Formerly the middle series in the Triassic was also known as Muschelkalk. This name is now only used for a specific unit of rock strata with approximately Middle Triassic age, found in western Europe.[citation needed] The Ashfield Shale and Bringelly Shale of western Sydney date to this epoch, with the former featuring fluvial fossils from that era.[8][9]

Middle Triassic life

Following the Permian–Triassic extinction event, the most devastating of all mass-extinctions, life recovered slowly. In the Middle Triassic, many groups of organisms reached higher diversity again, such as the marine reptiles (e.g. ichthyosaurs, sauropterygians, thallatosaurs), ray-finned fish and many invertebrate groups like molluscs (ammonoids, bivalves, gastropods).[citation needed]

During the Middle Triassic, there were not yet any flowering plants, but instead there were seed ferns and gymnosperms. Small dinosauriforms began to appear, like Nyasasaurus and the ichnogenus Iranosauripus.[citation needed]

References

Related Articles

Wikiwand AI