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Middle Devonian | |||||||||||||||||
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Chronology | |||||||||||||||||
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Etymology | |||||||||||||||||
Name formality | Formal | ||||||||||||||||
Usage information | |||||||||||||||||
Celestial body | Earth | ||||||||||||||||
Regional usage | Global (ICS) | ||||||||||||||||
Time scale(s) used | ICS Time Scale | ||||||||||||||||
Definition | |||||||||||||||||
Chronological unit | Epoch | ||||||||||||||||
Stratigraphic unit | Series | ||||||||||||||||
Time span formality | Formal | ||||||||||||||||
Lower boundary definition | Fad of the Conodont Polygnathus costatus partitus | ||||||||||||||||
Lower boundary GSSP | Wetteldorf Richtschnitt, Eifel hills, Germany 50°08′59″N 6°28′18″E / 50.1496°N 6.4716°E | ||||||||||||||||
Lower GSSP ratified | 1985 | ||||||||||||||||
Upper boundary definition | FAD of the Conodont Ancyrodella rotundibola | ||||||||||||||||
Upper boundary GSSP | Col du Puech de la Suque, Montagne Noire, France 43°30′12″N 3°05′12″E / 43.5032°N 3.0868°E | ||||||||||||||||
Upper GSSP ratified | 1986 |
In the geological timescale, the Middle Devonian epoch (from 397.5 ± 2.7 million years ago to 385.3 ± 2.6 million years ago) occurred during the Devonian period, after the end of the Emsian age.
The Middle Devonian epoch is subdivided into two stages: Eifelian and Givetian.