Triassic - Dating and Subdivisions

Dating and Subdivisions

Key events in the Triassic -255 — – -250 — – -245 — – -240 — – -235 — – -230 — – -225 — – -220 — – -215 — – -210 — – -205 — – -200 — – Jurassic Permian Triassic Induan Olenekian Anisian Ladinian Carnian Norian Rhaetian ← Mass extinction ← Full recovery of woody trees ← Coals return ← Scleractinian
corals & calcified sponges T
r
i
a
s
s
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c  Mesozoic
 Palæozoic
An approximate timescale of key Triassic events.
Axis scale: millions of years ago.

The Triassic is usually separated into Early, Middle, and Late Triassic Epochs, and the corresponding rocks are referred to as Lower, Middle, or Upper Triassic. The faunal stages from the youngest to oldest are:

Upper/Late Triassic (Tr3)
Rhaetian	(~208.5 – 201.3 ± 0.2 Mya)
Norian	(~228 – ~208.5 Mya)
Carnian	(~235 – ~228 Mya)
Middle Triassic (Tr2)
Ladinian	(~242 – ~235 Mya)
Anisian	(247.2 – ~242 Mya)
Lower/Early Triassic (Scythian)
Olenekian	(251.2 – 247.2 Mya)
Induan	(252.2 ± 0.5 – 251.2 Mya)