Llanvirn General Stage
(Llanvirnian, Guniutanian, Abereiddian)
From 471.8 +/- 1.6 To 464 Ma
Start Defined By: Conodont, potentially lowest occurrence of Protoprioniodus
aranda or of Baltoniodus triangularis.
Start Based On: Gradstein, Ogg, Smith, _A Geologic Time Scale 2004_
End Based On: Gradstein and Ogg, "A Phanerozoic time scale", _Episodes_,
v.19, no.1&2., 1996.
Comment: Competing definition considers the Llanvirn to represent the entire
Middle Ordovician, in which case the Abereiddian and Llandeilian are
considered to be it's stages.
-- Overlaps With --
ICS Stage: Darriwilian (468.1 - 460.9)
Australian Stage: Chewtonian (473 - 471)
-- A Substage of --
Eon: Phanerozoic (542 - -5.5012e-005)
Era: Paleozoic (542 - 251)
Period: Ordovician (488.3 - 443.7)
Epoch: Middle Ordovician (471.8 - 460.9)
North American Stage: White Rockian (471.8 - 462)
-- Preceeded By --
Epoch: Early Ordovician (488.3 - 471.8)
ICS Stage: Arenig (478.6 - 471.8)
Chinese Stage: Dawanian (472 - 471.8)
European Stage: Fennian (473.5 - 471.8)
North American Stage: Ibexian (491 - 471.8)
North American Stage: Cassinian (473 - 471.8)
-- Followed By --
General Stage: Llandeilo (464 - 460.9)
-- Contains the Following Stages --
ICS Stage: Ordovician III (471.8 - 468.1)
Australian Stage: Castlemanian (471 - 470)
Australian Stage: Ypeenian (470 - 468.1)
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