In the
geologic timescale
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geoch ...
, the Middle Triassic is the second of three
epochs of the
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...
period or the middle of three
series in which the Triassic
system is divided in
chronostratigraphy. The Middle Triassic spans the time between
Ma and Ma (million years ago). It is preceded by the
Early Triassic Epoch and followed by the
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...
Epoch. The Middle Triassic is divided into the
Anisian and
Ladinian ages Ages may refer to:
*Advanced glycation end-products, known as AGEs
*Ages, Kentucky, census-designated place, United States
* ''Ages'' (album) by German electronic musician Edgar Froese
*The geologic time scale, a system of chronological measuremen ...
or
stages.
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.
Middle Triassic fauna
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
Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria became ...
,
thallatosaur
Thalattosauria ( Greek for "sea lizards") is an extinct order of prehistoric marine reptiles that lived in the middle to late Triassic period. Thalattosaurs were diverse in size and shape, and are divided into two superfamilies: Askeptosauroidea ...
s),
ray-finned fish and many
invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
groups like
molluscs (
ammonoids,
bivalves,
gastropods).
During the Middle Triassic, there were no flowering plants, but instead there were ferns and mosses. Small dinosauriforms began to appear, like ''
Nyasasaurus
''Nyasasaurus'' (meaning " Lake Nyasa lizard") is an extinct genus of avemetatarsalian archosaur from the putatively Middle Triassic Manda Formation of Tanzania that may be the earliest known dinosaur. The type species ''Nyasasaurus parringt ...
'' and the ichnogenus ''
Iranosauripus
''Iranosauripus'' is an ichnogenus of dinosaur footprint discovered in Iran that supposedly belonged to a theropod. ''Iranosauripus'' supposedly existed during Middle Triassic-Early Jurassic, although the first true dinosaurs, such as ''Eoraptor'' ...
''.
File:Mixosaurus BW.jpg, '' Mixosaurus cornalianus'' restoration, a Middle Triassic ichthyosaur
References
GeoWhen Database - Middle Triassic
*02
Geological epochs
*02
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