Early Devonian

Short description: First epoch/series of the Devonian

Early Devonian

419.62 ± 1.36 – 393.47 ± 0.99 Ma

PreЄ

A map of Earth as it appeared 405 million years ago during the Early Devonian Epoch, Emsian Age

Sample from the Lower Devonian Rhynie chert

Chronology

Devonian Graphical Timeline

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-420 --

-415 --

-410 --

-405 --

-400 --

-395 --

-390 --

-385 --

-380 --

-375 --

-370 --

-365 --

-360 --

Mississippian

Přídolí

Early M

Lochkovian

Pragian

Emsian

Eifelian

Givetian

Frasnian

Famennian

Rhynie chert[1]

Hangenberg event

Kellwasser event(s)[2]

Widespread[3]
shrubs & trees

S. America
glaciation begins

Hunsrück fauna

Subdivision of the Devonian according to the ICS, as of 2021.[4]
Vertical axis scale: millions of years ago.

Etymology
Chronostratigraphic name| Lower Devonian
Geochronological name| Early Devonian
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 graptolite Monograptus uniformis
Lower boundary GSSP| Klonk, Czech Republic
[ ⚑ ] 49°51′18″N 13°47′31″E﻿ / ﻿49.8550°N 13.7920°E﻿ / 49.8550; 13.7920
GSSP ratified| 1972[5]
Upper boundary definition| FAD of the conodont Polygnathus costatus partitus
Upper boundary GSSP| Wetteldorf Richtschnitt section, Wetteldorf, Eifel, Germany
[ ⚑ ] 50°08′59″N 6°28′18″E﻿ / ﻿50.1496°N 6.4716°E﻿ / 50.1496; 6.4716
GSSP ratified| 1985[6]

The Early Devonian is the first of three epochs comprising the Devonian period, corresponding to the Lower Devonian series. It lasted from 419.2 million years ago to 393.3 ± 2.7 and began with the Lochkovian Stage 419.2 million years ago to 410.8 ± 2.7, which was followed by the Pragian from 410.8 million years ago to 407.6 ± 2.7 and then by the Emsian, which lasted until the Middle Devonian began, 393.3± 2.7 million years ago.[7] During this time, the first ammonoids appeared, descending from bactritoid nautiloids. Ammonoids during this time period were simple and differed little from their nautiloid counterparts. These ammonoids belong to the order Agoniatitida, which in later epochs evolved to new ammonoid orders, for example Goniatitida and Clymeniida. This class of cephalopod molluscs would dominate the marine fauna until the beginning of the Mesozoic Era.

## References

1. ↑ Parry, S. F.; Noble, S. R.; Crowley, Q. G.; Wellman, C. H. (2011). "A high-precision U–Pb age constraint on the Rhynie Chert Konservat-Lagerstätte: time scale and other implications". Journal of the Geological Society (London: Geological Society) 168 (4): 863–872. doi:10.1144/0016-76492010-043. http://jgs.lyellcollection.org/content/168/4/863.abstract.
2. ↑ Kaufmann, B.; Trapp, E.; Mezger, K. (2004). "The numerical age of the Upper Frasnian (Upper Devonian) Kellwasser horizons: A new U-Pb zircon date from Steinbruch Schmidt(Kellerwald, Germany)". The Journal of Geology 112 (4): 495–501. doi:10.1086/421077. Bibcode: 2004JG....112..495K.
3. ↑ Algeo, T. J. (1998). "Terrestrial-marine teleconnections in the Devonian: links between the evolution of land plants, weathering processes, and marine anoxic events". Philosophical Transactions of the Royal Society B: Biological Sciences 353 (1365): 113–130. doi:10.1098/rstb.1998.0195.
4. ↑ "Chart/Time Scale". International Commission on Stratigraphy. http://www.stratigraphy.org/index.php/ics-chart-timescale.
5. ↑ Chlupáč, Ivo; Hladil, Jindrich (January 2000). "The global stratotype section and point of the Silurian-Devonian boundary". CFS Courier Forschungsinstitut Senckenberg: 1–8. https://www.researchgate.net/publication/260135817. Retrieved 7 December 2020.
6. ↑ Ziegler, W.; Klapper, G. (June 1985). "Stages of the Devonian System". Episodes 8 (2): 104–109. doi:10.18814/epiiugs/1985/v8i2/006. https://stratigraphy.org/gssps/files/eifelian.pdf. Retrieved 18 December 2020.
7. ↑ Cohen, K.M.; Finney, S.C.; Gibbard, P.L.; Fan, J.-X. (2013). "The ICS International Chronostratigraphic Chart". Episodes 36 (3): 199–204. doi:10.18814/epiiugs/2013/v36i3/002. https://stratigraphy.org/ICSchart/Cohen2013_Episodes.pdf. Retrieved 7 January 2021.

Template:Devonian footer

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Geological history of Earth

Cenozoic era
(present–66.0 Mya)|

| Quaternary (present–2.588 Mya)|

* Holocene (present–11.784 kya)
* Pleistocene (11.784 kya–2.588 Mya)

|

Neogene (2.588–23.03 Mya)|

* Pliocene (2.588–5.333 Mya)
* Miocene (5.333–23.03 Mya)

Paleogene (23.03–66.0 Mya)|

* Oligocene (23.03–33.9 Mya)
* Eocene (33.9–56.0 Mya)
* Paleocene (56.0–66.0 Mya)

Mesozoic era
(66.0–251.902 Mya)|

| Cretaceous (66.0–145.0 Mya)|

* Late (66.0–100.5 Mya)
* Early (100.5–145.0 Mya)

|

Jurassic (145.0–201.3 Mya)|

* Late (145.0–163.5 Mya)
* Middle (163.5–174.1 Mya)
* Early (174.1–201.3 Mya)

Triassic (201.3–251.902 Mya)|

* Late (201.3–237 Mya)
* Middle (237–247.2 Mya)
* Early (247.2–251.902 Mya)

Paleozoic era
(251.902–541.0 Mya)|

| Permian (251.902–298.9 Mya)|

* Lopingian (251.902–259.8 Mya)
* Guadalupian (259.8–272.3 Mya)
* Cisuralian (272.3–298.9 Mya)

|

Carboniferous (298.9–358.9 Mya)|

* Pennsylvanian (298.9–323.2 Mya)
* Mississippian (323.2–358.9 Mya)

Devonian (358.9–419.2 Mya)|

* Late (358.9–382.7 Mya)
* Middle (382.7–393.3 Mya)
* Early (393.3–419.2 Mya)

Silurian (419.2–443.8 Mya)|

* Pridoli (419.2–423.0 Mya)
* Ludlow (423.0–427.4 Mya)
* Wenlock (427.4–433.4 Mya)
* Llandovery (433.4–443.8 Mya)

Ordovician (443.8–485.4 Mya)|

* Late (443.8–458.4 Mya)
* Middle (458.4–470.0 Mya)
* Early (470.0–485.4 Mya)

Cambrian (485.4–541.0 Mya)|

* Furongian (485.4–497 Mya)
* Miaolingian (497–509 Mya)
* Series 2 (509–521 Mya)
* Terreneuvian (521–541.0 Mya)

Proterozoic eon
(541.0 Mya–2.5 Gya)|

| Neoproterozoic (541.0 Mya–1 Gya)|

* Ediacaran (541.0–~635 Mya)
* Cryogenian (~635–~720 Mya)
* Tonian (~720 Mya–1 Gya)

|

Mesoproterozoic (1–1.6 Gya)|

* Stenian (1–1.2 Gya)
* Ectasian (1.2–1.4 Gya)
* Calymmian (1.4–1.6 Gya)

Paleoproterozoic (1.6–2.5 Gya)|

* Statherian (1.6–1.8 Gya)
* Orosirian (1.8–2.05 Gya)
* Rhyacian (2.05–2.3 Gya)
* Siderian (2.3–2.5 Gya)

Archean eon (2.5–4 Gya)|

| Eras|

* Neoarchean (2.5–2.8 Gya)
* Mesoarchean (2.8–3.2 Gya)
* Paleoarchean (3.2–3.6 Gya)
* Eoarchean (3.6–4 Gya)

|

Hadean eon (4–4.6 Gya)|

|  |

|

kya = thousands years ago. Mya = millions years ago. Gya = billions years ago.
See also: Geologic time scale

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