Paleogene

First period of the Cenozoic Era (66–23 million years ago)

Not to be confused with Paleocene.

This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages)

This article may need to be rewritten to comply with Wikipedia's quality standards. You can help. The talk page may contain suggestions. (November 2023)

|

This article needs attention from an expert in Geology or Palaeontology. The specific problem is: Too technical: See talk page. WikiProject Geology or WikiProject Palaeontology may be able to help recruit an expert. (November 2023)

|

(Learn how and when to remove this message)

Paleogene

66.0 – 22.97 Ma

PreꞒ

A map of Earth as it appeared during the Eocene epoch, c. 50 Ma.[citation needed]

Chronology

−65 --

−60 --

−55 --

−50 --

−45 --

−40 --

−35 --

−30 --

−25 --

Cretaceous

Neogene

Danian

Selandian

Thanetian

Ypresian

Lutetian

Bartonian

Priabonian

Rupelian

Chattian

| | <-|

PETM

|

<-|

First Antarctic permanent ice-sheets[1]

|

<-|

K-Pg mass
extinction

|

Subdivision of the Paleogene according to the ICS, as of 2021.[2]
Vertical axis scale: millions of years ago

Etymology
Name formality| Formal
Alternate spelling(s)| Palaeogene, Palæogene
Usage information
Celestial body| Earth
Regional usage| Global (ICS)
Time scale(s) used| ICS Time Scale
Definition
Chronological unit| Period
Stratigraphic unit| System
Time span formality| Formal
Lower boundary definition| Iridium enriched layer associated with a major meteorite impact and subsequent K-Pg extinction event.
Lower boundary GSSP| El Kef Section, El Kef, Tunisia
36°09′13″N 8°38′55″E﻿ / ﻿36.1537°N 8.6486°E﻿ / 36.1537; 8.6486
Lower GSSP ratified| 1991[3]
Upper boundary definition|

* Base of magnetic polarity chronozone C6Cn.2n.
* Near first appearance of the Planktonic foraminiferan Paragloborotalia kugleri.

Upper boundary GSSP| Lemme-Carrosio Section, Carrosio, Italy
44°39′32″N 8°50′11″E﻿ / ﻿44.6589°N 8.8364°E﻿ / 44.6589; 8.8364
Upper GSSP ratified| 1996[4]
Atmospheric and climatic data
Mean atmospheric O2 content| c. 26 vol %
(125 % of modern)
Mean atmospheric CO2 content| c. 500 ppm
(1.8 times pre-industrial)
Mean surface temperature| c. 18 °C
(4.5 °C above pre-industrial)

The Paleogene Period (IPA: /ˈpeɪli.ədʒiːn, -li.oʊ-, ˈpæli-/ PAY-lee-ə-jeen, -⁠lee-oh-, PAL-ee-; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period 66 Ma (million years ago) to the beginning of the Neogene Period 23.03 Ma. It is the first period of the Cenozoic Era and is divided into the Paleocene, Eocene, and Oligocene epochs. The earlier term Tertiary Period was used to define the time now covered by the Paleogene Period and subsequent Neogene Period; despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use.[5] Paleogene is often abbreviated "Pg", although the United States Geological Survey uses the abbreviation "Pe" for the Paleogene on the Survey's geologic maps.[6][7]

During the Paleogene period, mammals continued to diversify from relatively small, simple forms into a large group of diverse animals in the wake of the Cretaceous–Paleogene extinction event that ended the preceding Cretaceous Period.[8]

The Period is marked by considerable changes in climate from the Paleocene–Eocene Thermal Maximum, through global cooling during the Eocene to the first appearance of permanent ice sheets in the Antarctic at the beginning of the Oligocene.[9]

## Geology[edit]

### Stratigraphy[edit]

The Paleogene is divided into three series/epochs: the Paleocene, Eocene, and Oligocene. These stratigraphic units can be defined globally or regionally. For global stratigraphic correlation, the International Commission on Stratigraphy (ICS) ratify global stages based on a Global Boundary Stratotype Section and Point (GSSP) from a single formation (a stratotype) identifying the lower boundary of the stage.[10]

#### Paleocene[edit]

The Paleocene is the first series/epoch of the Paleogene and lasted from 66.0 Ma to 56.0 Ma. It is divided into three stages: the Danian 66.0 - 61.6 Ma; Selandian 61.6 - 59.2 Ma; and, Thanetian 59.2 - 56.0 Ma.[11] The GSSP for the base of the Cenozoic, Paleogene and Paleocene is at Oued Djerfane, west of El Kef, Tunisia. It is marked by an iridium anomaly produced by an asteroid impact, and is associated with the Cretaceous–Paleogene extinction event. The boundary is defined as the rusty colored base of a 50 cm thick clay, which would have been deposited over only a few days. Similar layers are seen in marine and continental deposits worldwide. These layers include the iridium anomaly, microtektites, nickel-rich spinel crystals and shocked quartz, all indicators of a major extraterrestrial impact. The remains of the crater are found at Chicxulub on the Yucatan Peninsula in Mexico. The extinction of the non-avian dinosaurs, ammonites and dramatic changes in marine plankton and many other groups of organisms, are also used for correlation purposes.[11]

#### Eocene[edit]

The Eocene is the second series/epoch of the Paleogene, and lasted from 56.0 Ma to 33.9 Ma. It is divided into four stages: the Ypresian 56.0 Ma to 47.8 Ma; Lutetian 47.8 Ma to 41.2 Ma; Bartonian 41.2 Ma to 37.71 Ma; and, Priabonian 37.71 Ma to 33.9 Ma. The GSSP for the base of the Eocene is at Dababiya, near Luxor, Egypt and is marked by the start of a significant variation in global carbon isotope ratios, produced by a major period of global warming. The change in climate was due to a rapid release of frozen methane clathrates from seafloor sediments at the beginning of the Paleocene-Eocene thermal maximum (PETM).[11]

#### Oligocene[edit]

The Oligocene is the third and youngest series/epoch of the Paleogene, and lasted from 33.9 Ma to 23.03 Ma. It is divided into two stages: the Rupelian 33.9 Ma to 27.82 Ma; and, Chattian 27.82 - 23.03 Ma. The GSSP for the base of the Oligocene is at Massignano, near Ancona, Italy. The extinction the hantkeninid planktonic foraminifera is the key marker for the Eocene-Oligocene boundary, which was a time of climate cooling that led to widespread changes in fauna and flora.[11]

## Climate[edit]

The global climate of the Paleogene began with the brief but intense "impact winter" caused by the Chicxulub impact. This cold period was terminated by an abrupt warming. After temperatures stabilised, the steady cooling and drying of the Late Cretaceous-Early Paleogene Cool Interval (LKEPCI) that had spanned the last two ages of the Late Cretaceous continued.[9] About 62.2 Mya, the Latest Danian Event, a hyperthermal event, took place.[12][13][14] About 59 Ma, the LKEPCI was brought to an end by the Thanetian Thermal Event, a change from the relative cool of the Early and Middle Palaeocene and the beginning of an intense supergreenhouse effect.[9]

According to a study published in 2018, from about 56 to 48 Mya, annual air temperatures over land and at mid-latitude averaged about 23–29 °C (± 4.7 °C), which is 5–10 °C warmer than most previous estimates.[15][16][17] For comparison, this was 10 to 15 °C greater than the current annual mean temperatures in these areas.[17] At the Palaeocene-Eocene boundary, the Paleocene–Eocene Thermal Maximum (PETM) occurred,[18] one of the warmest times of the Phanerozoic eon, during which global mean surface temperatures increased to 31.6.[19] It was followed by the less severe Eocene Thermal Maximum 2 (ETM2) about 53.69 Ma.[20] Eocene Thermal Maximum 3 (ETM3) occurred about 53 Ma. The Early Eocene Climatic Optimum was brought to an end by the Azolla event, a change of climate about 48.5 Mya, believed to have been caused by a proliferation of aquatic ferns from the genus Azolla, resulting in the sequestering of large amounts of carbon dioxide by those plants. From this time until about 34 Mya, there was a slow cooling trend known as the Middle-Late Eocene Cooling (MLEC).[9] Approximately 41.5 Mya, this cooling was interrupted temporarily by the Middle Eocene Climatic Optimum (MECO).[21] Then, about 39.4 Mya, a temperature decrease termed the Late Eocene Cool Event (LECE) is detected in the oxygen isotope record.[9] A rapid decrease of global temperatures and formation of continental glaciers on Antarctica marked the end of the Eocene.[22] This sudden cooling was caused partly by the formation of the Antarctic Circumpolar Current,[23] which significantly lowered oceanic water temperatures.[24]

During the earliest Oligocene occurred the Early Oligocene Glacial Maximum (Oi1), which lasted for about 200,000 years.[25] After Oi1, global mean surface temperature continued to decrease gradually during the Rupelian Age. [9] Another major cooling event occurred at the end of the Rupelian; its most likely cause was extreme biological productivity in the Southern Ocean fostered by tectonic reorganisation of ocean currents and an influx of nutrients from Antarctica.[26] In the Late Oligocene, global temperatures began to warm slightly, though they continued to be significantly lower than during the previous epochs of the Paleogene and polar ice remained.[9]

## Palaeogeography[edit]

During the Paleogene, the continents continued to drift closer to their current positions. India was in the process of colliding with Asia, forming the Himalayas. The Atlantic Ocean continued to widen by a few centimeters each year. Africa was moving north to collide with Europe and form the Mediterranean Sea, while South America was moving closer to North America (they would later connect at the Isthmus of Panama). Inland seas retreated from North America early in the period. Australia had also separated from Antarctica and was drifting toward Southeast Asia. The 1.2 million year cycle of obliquity amplitude modulation governed eustatic sea level changes on shorter timescales, with periods of low amplitude coinciding with intervals of low sea levels and vice versa.[27]

## Flora and fauna[edit]

Tropical taxa diversified faster than those at higher latitudes after the Cretaceous–Paleogene extinction event, resulting in the development of a significant latitudinal diversity gradient.[28] Mammals began a rapid diversification during this period. After the Cretaceous–Paleogene extinction event, which saw the demise of the non-avian dinosaurs, mammals began to evolve from a few small and generalized forms into most of the modern varieties we see presently. Some of these mammals evolved into large forms that dominated the land, while others became capable of living in marine, specialized terrestrial, and airborne environments. Those that adapted to the oceans became modern cetaceans, while those that adapted to trees became primates, the group to which humans belong. Birds, extant dinosaurs which were already well established by the end of the Cretaceous, also experienced adaptive radiation as they took over the skies left empty by the now extinct pterosaurs. Some flightless birds such as penguins, ratites, and terror birds also filled niches left by the hesperornithes and other extinct dinosaurs.

Pronounced cooling in the Oligocene resulted in a massive floral shift, and many extant modern plants arose during this time. Grasses and herbs, such as Artemisia, began to proliferate, at the expense of tropical plants, which began to decrease. Conifer forests developed in mountainous areas. This cooling trend continued, with major fluctuation, until the end of the Pleistocene period.[29] This evidence for this floral shift is found in the palynological record.[30] Some important flora were, grasses, beeches, monocots, pines and kauri.

## See also[edit]

* Cretaceous–Paleogene boundary – Geological boundary between time periods

## References[edit]

1. ^ Zachos, J. C.; Kump, L. R. (2005). "Carbon cycle feedbacks and the initiation of Antarctic glaciation in the earliest Oligocene". Global and Planetary Change. 47 (1): 51–66. Bibcode:2005GPC....47...51Z. doi:10.1016/j.gloplacha.2005.01.001.
2. ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy.
3. ^ Molina, Eustoquio; Alegret, Laia; Arenillas, Ignacio; José A. Arz; Gallala, Njoud; Hardenbol, Jan; Katharina von Salis; Steurbaut, Etienne; Vandenberghe, Noel; Dalila Zaghibib-Turki (2006). "The Global Boundary Stratotype Section and Point for the base of the Danian Stage (Paleocene, Paleogene, "Tertiary", Cenozoic) at El Kef, Tunisia - Original definition and revision". Episodes. 29 (4): 263–278. doi:10.18814/epiiugs/2006/v29i4/004.
4. ^ Steininger, Fritz F.; M. P. Aubry; W. A. Berggren; M. Biolzi; A. M. Borsetti; Julie E. Cartlidge; F. Cati; R. Corfield; R. Gelati; S. Iaccarino; C. Napoleone; F. Ottner; F. Rögl; R. Roetzel; S. Spezzaferri; F. Tateo; G. Villa; D. Zevenboom (1997). "The Global Stratotype Section and Point (GSSP) for the base of the Neogene" (PDF). Episodes. 20 (1): 23–28. doi:10.18814/epiiugs/1997/v20i1/005.
5. ^ "GeoWhen Database – What Happened to the Tertiary?". www.stratigraphy.org.
6. ^ Federal Geographic Data Committee. "FGDC Digital Cartographic Standard for Geologic Map Symbolization" (PDF). The National Geologic Map Database. United States Geological Survey. Retrieved 29 January 2022.
7. ^ Orndorff, R.C. (20 July 2010). "Divisions of Geologic Time—Major Chronostratigraphic and Geochronologic Units" (PDF). United States Geological Survey. Retrieved 29 January 2022.
8. ^ Meredith, R. W.; Janecka, J. E.; Gatesy, J.; Ryder, O. A.; Fisher, C. A.; Teeling, E. C.; Goodbla, A.; Eizirik, E.; Simao, T. L. L.; Stadler, T.; Rabosky, D. L.; Honeycutt, R. L.; Flynn, J. J.; Ingram, C. M.; Steiner, C.; Williams, T. L.; Robinson, T. J.; Burk-Herrick, A.; Westerman, M.; Ayoub, N. A.; Springer, M. S.; Murphy, W. J. (28 October 2011). "Impacts of the Cretaceous Terrestrial Revolution and KPg Extinction on Mammal Diversification". Science. 334 (6055): 521–524. Bibcode:2011Sci...334..521M. doi:10.1126/science.1211028. PMID 21940861. S2CID 38120449.
9. ^ a b c d e f g Scotese, Christopher Robert; Song, Haijun; Mills, Benjamin J.W.; van der Meer, Douwe G. (April 2021). "Phanerozoic paleotemperatures: The earth's changing climate during the last 540 million years". Earth-Science Reviews. 215: 103503. Bibcode:2021ESRv..21503503S. doi:10.1016/j.earscirev.2021.103503. S2CID 233579194. Retrieved 23 September 2023.
10. ^ "International Commission on Stratigraphy". stratigraphy.org. Retrieved 2024-07-15.
11. ^ a b c d Vandenberghe, N.; Hilgen, F. J.; Speijer, R. P.; Ogg, J. G.; Gradstein, F. M.; Hammer, O.; Hollis, C. J.; Hooker, J. J. (2012-01-01), Gradstein, Felix M.; Ogg, James G.; Schmitz, Mark D.; Ogg, Gabi M. (eds.), "Chapter 28 - The Paleogene Period", The Geologic Time Scale, Boston: Elsevier, pp. 855–921, ISBN 978-0-444-59425-9, retrieved 2024-07-15
12. ^ Jehle, Sofie; Bornemann, André; Lägel, Anna Friederike; Deprez, Arne; Speijer, Robert P. (1 July 2019). "Paleoceanographic changes across the Latest Danian Event in the South Atlantic Ocean and planktic foraminiferal response". Palaeogeography, Palaeoclimatology, Palaeoecology. 525: 1–13. Bibcode:2019PPP...525....1J. doi:10.1016/j.palaeo.2019.03.024. S2CID 134929774. Retrieved 30 December 2022.
13. ^ Jehle, Sofie; Bornemann, André; Deprez, Arne; Speijer, Robert P. (25 November 2015). "The Impact of the Latest Danian Event on Planktic Foraminiferal Faunas at ODP Site 1210 (Shatsky Rise, Pacific Ocean)". PLOS ONE. 10 (11): e0141644. Bibcode:2015PLoSO..1041644J. doi:10.1371/journal.pone.0141644. PMC 4659543. PMID 26606656.
14. ^ Sprong, M.; Youssef, J. A.; Bornemann, André; Schulte, P.; Steurbaut, E.; Stassen, P.; Kouwenhoven, T. J.; Speijer, Robert P. (September 2011). "A multi-proxy record of the Latest Danian Event at Gebel Qreiya, Eastern Desert, Egypt" (PDF). Journal of Micropalaeontology. 30 (2): 167–182. Bibcode:2011JMicP..30..167S. doi:10.1144/0262-821X10-023. S2CID 55038043. Archived from the original (PDF) on 28 June 2023. Retrieved 30 December 2022.
15. ^ Naafs, B. D. A.; Rohrssen, M.; Inglis, G. N.; Lähteenoja, O.; Feakins, S. J.; Collinson, M. E.; Kennedy, E. M.; Singh, P. K.; Singh, M. P.; Lunt, D. J.; Pancost, R. D. (2018). "High temperatures in the terrestrial mid-latitudes during the early Palaeogene" (PDF). Nature Geoscience. 11 (10): 766–771. Bibcode:2018NatGe..11..766N. doi:10.1038/s41561-018-0199-0. hdl:1983/82e93473-2a5d-4a6d-9ca1-da5ebf433d8b. S2CID 135045515.
16. ^ University of Bristol (30 July 2018). "Ever-increasing CO2 levels could take us back to the tropical climate of Paleogene period". ScienceDaily.
17. ^ a b "Ever-increasing CO2 levels could take us back to the tropical climate of Paleogene period". University of Bristol. 2018.
18. ^ Wing, S. L. (11 November 2005). "Transient Floral Change and Rapid Global Warming at the Paleocene-Eocene Boundary". Science. 310 (5750): 993–996. Bibcode:2005Sci...310..993W. doi:10.1126/science.1116913. ISSN 0036-8075. PMID 16284173. S2CID 7069772. Retrieved 23 September 2023.
19. ^ Inglis, Gordon N.; Bragg, Fran; Burls, Natalie J.; Cramwinckel, Margot J.; Evans, David; Foster, Gavin L.; Huber, Matthew; Lunt, Daniel J.; Siler, Nicholas; Steinig, Sebastian; Tierney, Jessica E.; Wilkinson, Richard; Anagnostou, Eleni; de Boer, Agatha M.; Dunkley Jones, Tom (26 October 2020). "Global mean surface temperature and climate sensitivity of the early Eocene Climatic Optimum (EECO), Paleocene–Eocene Thermal Maximum (PETM), and latest Paleocene". Climate of the Past. 16 (5): 1953–1968. Bibcode:2020CliPa..16.1953I. doi:10.5194/cp-16-1953-2020. hdl:1983/24a30f12-51a6-4544-9db8-b2009e33c02a. ISSN 1814-9332. Retrieved 23 September 2023.
20. ^ Stap, L.; Lourens, L.J.; Thomas, E.; Sluijs, A.; Bohaty, S.; Zachos, J.C. (1 July 2010). "High-resolution deep-sea carbon and oxygen isotope records of Eocene Thermal Maximum 2 and H2". Geology. 38 (7): 607–610. Bibcode:2010Geo....38..607S. doi:10.1130/G30777.1. hdl:1874/385773. S2CID 41123449.
21. ^ Bohaty, Steven M.; Zachos, James C. (1 November 2003). "Significant Southern Ocean warming event in the late middle Eocene". Geology. 31 (11): 1017. Bibcode:2003Geo....31.1017B. doi:10.1130/G19800.1. ISSN 0091-7613. Retrieved 23 September 2023.
22. ^ Pearson, Paul N.; Foster, Gavin L.; Wade, Bridget S. (13 September 2009). "Atmospheric carbon dioxide through the Eocene–Oligocene climate transition". Nature. 461 (7267): 1110–1113. Bibcode:2009Natur.461.1110P. doi:10.1038/nature08447. ISSN 0028-0836. PMID 19749741. S2CID 205218274. Retrieved 23 September 2023.
23. ^ Sauermilch, Isabel; Whittaker, Joanne M.; Klocker, Andreas; Munday, David R.; Hochmuth, Katharina; Bijl, Peter K.; LaCasce, Joseph H. (9 November 2021). "Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling". Nature Communications. 12 (1): 6465. Bibcode:2021NatCo..12.6465S. doi:10.1038/s41467-021-26658-1. ISSN 2041-1723. PMC 8578591. PMID 34753912.
24. ^ Barker, P.F.; Thomas, E. (June 2004). "Origin, signature and palaeoclimatic influence of the Antarctic Circumpolar Current". Earth-Science Reviews. 66 (1–2): 143–162. Bibcode:2004ESRv...66..143B. doi:10.1016/j.earscirev.2003.10.003. Retrieved 23 September 2023.
25. ^ Zachos, James C.; Lohmann, Kyger C.; Walker, James C. G.; Wise, Sherwood W. (March 1993). "Abrupt Climate Change and Transient Climates during the Paleogene: A Marine Perspective". The Journal of Geology. 101 (2): 191–213. Bibcode:1993JG....101..191Z. doi:10.1086/648216. ISSN 0022-1376. PMID 11537739. S2CID 29784731. Retrieved 23 September 2023.
26. ^ Hochmuth, Katharina; Whittaker, Joanne M.; Sauermilch, Isabel; Klocker, Andreas; Gohl, Karsten; LaCasce, Joseph H. (9 November 2022). "Southern Ocean biogenic blooms freezing-in Oligocene colder climates". Nature Communications. 13 (1): 6785. Bibcode:2022NatCo..13.6785H. doi:10.1038/s41467-022-34623-9. ISSN 2041-1723. PMC 9646741. PMID 36351905.
27. ^ Liu, Yang; Huang, Chunju; Ogg, James G.; Algeo, Thomas J.; Kemp, David B.; Shen, Wenlong (15 September 2019). "Oscillations of global sea-level elevation during the Paleogene correspond to 1.2-Myr amplitude modulation of orbital obliquity cycles". Earth and Planetary Science Letters. 522: 65–78. Bibcode:2019E&PSL.522...65L. doi:10.1016/j.epsl.2019.06.023. S2CID 198431567. Retrieved 24 November 2022.
28. ^ Crame, J. Alistair (March 2020). "Early Cenozoic evolution of the latitudinal diversity gradient". Earth-Science Reviews. 202: 103090. Bibcode:2020ESRv..20203090C. doi:10.1016/j.earscirev.2020.103090. S2CID 214219923.
29. ^ Traverse, Alfred (1988). Paleopalynology. Unwin Hyman. ISBN 978-0-04-561001-3. OCLC 17674795.
30. ^ Muller, Jan (January 1981). "Fossil pollen records of extant angiosperms". The Botanical Review. 47 (1): 1–142. Bibcode:1981BotRv..47....1M. doi:10.1007/bf02860537. ISSN 0006-8101. S2CID 10574478.

## External links[edit]

Wikisource has original works on the topic: Cenozoic#Paleogene

Wikimedia Commons has media related to Paleogene.

* Paleogene Microfossils: 180+ images of Foraminifera
* Paleogene (chronostratigraphy scale)

* v
* t
* e

Paleogene Period

| Paleocene Epoch| Eocene Epoch| Oligocene Epoch

|
|

* Danian
* Selandian
* Thanetian

* Ypresian
* Lutetian
* Bartonian
* Priabonian

* Rupelian
* Chattian

* v
* t
* e

Geological history of Earth

Cenozoic Era
(present–66.0 Ma)|

| Quaternary (present–2.58 Ma)|

* Holocene (present–11.7 ka)
* Pleistocene (11.7 ka–2.58 Ma)

|

Neogene (2.58–23.0 Ma)|

* Pliocene (2.59–5.33 Ma)
* Miocene (5.33–23.0 Ma)

Paleogene (23.0–66.0 Ma)|

* Oligocene (23.0–33.9 Ma)
* Eocene (33.9–56.0 Ma)
* Paleocene (56.0–66.0 Ma)

Mesozoic Era
(66.0–252 Ma)|

| Cretaceous (66.0–145 Ma)|

* Late (66.0–100 Ma)
* Early (100–145 Ma)

|

Jurassic (145–201 Ma)|

* Late (145–164 Ma)
* Middle (164–174 Ma)
* Early (174–201 Ma)

Triassic (201–252 Ma)|

* Late (201–237 Ma)
* Middle (237–247 Ma)
* Early (247–252 Ma)

Paleozoic Era
(252–539 Ma)|

| Permian (252–299 Ma)|

* Lopingian (252–260 Ma)
* Guadalupian (260–272 Ma)
* Cisuralian (272–299 Ma)

|

Carboniferous (299–359 Ma)|

* Pennsylvanian (299–323 Ma)
* Mississippian (323–359 Ma)

Devonian (359–419 Ma)|

* Late (359–383 Ma)
* Middle (383–393 Ma)
* Early (393–419 Ma)

Silurian (419–444 Ma)|

* Pridoli (419–423 Ma)
* Ludlow (423–427 Ma)
* Wenlock (427–433 Ma)
* Llandovery (433–444 Ma)

Ordovician (444–485 Ma)|

* Late (444–458 Ma)
* Middle (458–470 Ma)
* Early (470–485 Ma)

Cambrian (485–539 Ma)|

* Furongian (485–497 Ma)
* Miaolingian (497–509 Ma)
* Series 2 (509–521 Ma)
* Terreneuvian (521–539 Ma)

Proterozoic Eon
(539 Ma–2.5 Ga)|

| Neoproterozoic (539 Ma–1 Ga)|

* Ediacaran (539–635 Ma)
* Cryogenian (635–720 Ma)
* Tonian (720 Ma–1 Ga)

|

Mesoproterozoic (1–1.6 Ga)|

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

Paleoproterozoic (1.6–2.5 Ga)|

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

Archean Eon (2.5–4 Ga)|

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

Hadean Eon (4–4.6 Ga)|

ka = kiloannum (thousands years ago); Ma = megaannum (millions years ago); Ga = gigaannum (billions years ago).
See also: Geologic time scale • Geology portal • World portal

Authority control databases: National |

* France
* BnF data
* Germany
* Israel
* United States
* Czech Republic

|

*[c.]: circa
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template