Early Devonian Epoch
(Lower Devonian, Helderbergian)
From 416 +/- 2.8 To 397.5 +/- 2.7 Ma
Start Defined By: Graptolite, lowest occurrence of Monograptus uniformis.
End Defined By: Conodont, lowest occurrence of Polygnathus costatus
partitus; major faunal turnover.
Start Based On: Gradstein, Ogg, Smith, _A Geologic Time Scale 2004_
End Based On: Gradstein, Ogg, Smith, _A Geologic Time Scale 2004_
-- A Substage of --
Eon: Phanerozoic (542 - -5.5012e-005)
Era: Paleozoic (542 - 251)
Period: Devonian (416 - 359.2)
North American Stage: Ulsterian (416 - 391.8)
-- Preceeded By --
Period: Silurian (443.7 - 416)
Epoch: Late Silurian (422.9 - 416)
Sub-Epoch: Pridoli (418.7 - 416)
Australian Stage: Melbournian (428.2 - 416)
North American Stage: Cayugan (421.3 - 416)
-- Followed By --
Epoch: Middle Devonian (397.5 - 385.3)
ICS Stage: Eifelian (397.5 - 391.8)
Chinese Stage: Yingtangian (397.5 - 391.4)
-- Contains the Following Stages --
ICS Stage: Lochkovian (416 - 411.2)
ICS Stage: Praghian (411.2 - 407)
ICS Stage: Emsian (407 - 397.5)
Chinese Stage: Yujianian (410 - 407)
Chinese Stage: Lianhuashanian (416 - 413)
Chinese Stage: Nagaolingian (413 - 410)
|
