Editing Geologic time scale (section)

== Naming of geologic time ==
The names of geologic time units are defined for chronostratigraphic units with the corresponding geochronologic unit sharing the same name with a change to the suffix (e.g. Phanerozoic [[Eonothem]] becomes the Phanerozoic Eon). Names of erathems in the Phanerozoic were chosen to reflect major changes in the history of life on Earth: [[Paleozoic]] (old life), [[Mesozoic]] (middle life), and [[Cenozoic]] (new life). Names of systems are diverse in origin, with some indicating chronologic position (e.g., Paleogene), while others are named for [[lithology]] (e.g., Cretaceous), [[geography]] (e.g., [[Permian]]), or are tribal (e.g., [[Ordovician]]) in origin. Most currently recognised series and subseries are named for their position within a system/series (early/middle/late); however, the International Commission on Stratigraphy advocates for all new series and subseries to be named for a geographic feature in the vicinity of its [[stratotype]] or [[Type locality (geology)|type locality]]. The name of stages should also be derived from a geographic feature in the locality of its stratotype or type locality.<ref name="ICS_chronostrat" />

Informally, the time before the Cambrian is often referred to as the [[Precambrian]] or pre-Cambrian (Supereon).<ref name="Shields_2022_pre-Cryogenian" />{{efn|Precambrian or pre-Cambrian is an informal geological term for time before the Cambrian period|name=Precam|group=note}}

{| class="wikitable mw-collapsible" style = "margin-left: auto; margin-right: auto; border: none;"
|+Time span and [[etymology]] of geologic eonothem/eon names
!Name
!Time span
!Duration (million years)
!Etymology of name
|-
|[[Phanerozoic]]
|{{Period span/brief|Phanerozoic|1}}
|{{#expr:{{Period start|Phanerozoic}}-{{Period end|Phanerozoic}}}}
|From Greek φανερός (''phanerós'') 'visible' or 'abundant' and ζωή (''zoē'') 'life'.
|-
|[[Proterozoic]]
|{{Period span/brief|Proterozoic|1}}
|{{#expr:{{Period start|Proterozoic}}-{{Period end|Proterozoic}}}}
|From Greek πρότερος (''próteros'') 'former' or 'earlier' and ζωή (''zoē'') 'life'.
|-
|[[Archean]]
|{{Period span/brief|Archean|1}}
|{{#expr:{{Period start|Archean}}-{{Period end|Archean}}}}
|From Greek [[ἀρχή]] (''archē'') 'beginning, origin'.
|-
|[[Hadean]]
|{{Period span/brief|Hadean|1}}
|{{#expr:{{Period start|Hadean}}-{{Period end|Hadean}}}}
|From [[Hades]], {{langx|grc|ᾍδης|Háidēs}}, the god of the underworld (hell, the inferno) in Greek mythology.
|}
{| class="wikitable mw-collapsible" style = "margin-left: auto; margin-right: auto; border: none;"
|+Time span and etymology of geologic erathem/era names
!Name
!Time span
!Duration (million years)
!Etymology of name
|-
|[[Cenozoic]]
|{{Period span/brief|Cenozoic|1}}
|{{#expr:{{Period start|Cenozoic}}-{{Period end|Cenozoic}}}}
|From Greek καινός (''kainós'') 'new' and ζωή (''zōḗ'') 'life'.
|-
|[[Mesozoic]]
|{{Period span/brief|Mesozoic|1}}
|{{#expr:{{Period start|Mesozoic}}-{{Period end|Mesozoic}}}}
|From Greek μέσο (''méso'') 'middle' and ζωή (''zōḗ'') 'life'.
|-
|[[Paleozoic]]
|{{Period span/brief|Paleozoic|1}}
|{{#expr:{{Period start|Paleozoic}}-{{Period end|Paleozoic}}}}
|From Greek παλιός (''palaiós'') 'old' and ζωή (''zōḗ'') 'life'.
|-
|[[Neoproterozoic]]
|{{Period span/brief|Neoproterozoic|1}}
|{{#expr:{{Period start|Neoproterozoic}}-{{Period end|Neoproterozoic}}}}
|From Greek νέος (''néos'') 'new' or 'young', πρότερος (''próteros'') 'former' or 'earlier', and ζωή (''zōḗ'') 'life'.
|-
|[[Mesoproterozoic]]
|{{Period span/brief|Mesoproterozoic|1}}
|{{#expr:{{Period start|Mesoproterozoic}}-{{Period end|Mesoproterozoic}}}}
|From Greek μέσο (''méso'') 'middle', πρότερος (''próteros'') 'former' or 'earlier', and ζωή (''zōḗ'') 'life'.
|-
|[[Paleoproterozoic]]
|{{Period span/brief|Paleoproterozoic|1}}
|{{#expr:{{Period start|Paleoproterozoic}}-{{Period end|Paleoproterozoic}}}}
|From Greek παλιός (''palaiós'') 'old', πρότερος (''próteros'') 'former' or 'earlier', and ζωή (''zōḗ'') 'life'.
|-
|[[Neoarchean]]
|{{Period span/brief|Neoarchean|1}}
|{{#expr:{{Period start|Neoarchean}}-{{Period end|Neoarchean}}}}
|From Greek νέος (''néos'') 'new' or 'young' and ἀρχαῖος (''arkhaîos'') 'ancient'.
|-
|[[Mesoarchean]]
|{{Period span/brief|Mesoarchean|1}}
|{{#expr:{{Period start|Mesoarchean}}-{{Period end|Mesoarchean}}}}
|From Greek μέσο (''méso'') 'middle' and ἀρχαῖος (''arkhaîos'') 'ancient'.
|-
|[[Paleoarchean]]
|{{Period span/brief|Paleoarchean|1}}
|{{#expr:{{Period start|Paleoarchean}}-{{Period end|Paleoarchean}}}}
|From Greek παλιός (''palaiós'') 'old' and ἀρχαῖος (''arkhaîos'') 'ancient'.
|-
|[[Eoarchean]]
|{{Period span/brief|Eoarchean|1}}
|{{#expr:{{Period start|Eoarchean}}-{{Period end|Eoarchean}}}}
|From Greek ἠώς (''ēōs'') 'dawn' and ἀρχαῖος (''arkhaîos'') 'ancient'.
|}
{| class="wikitable mw-collapsible" style = "margin-left: auto; margin-right: auto; border: none;"
|+Time span and etymology of geologic system/period names
!Name
!Time span
!Duration (million years)
!Etymology of name
|-
|[[Quaternary]]
|{{Period span/brief|Quaternary|1}}
|{{#expr:{{Period start|Quaternary}}-{{Period end|Quaternary}}}}
|First introduced by [[Jules Desnoyers]] in 1829 for sediments in [[France]]'s [[Seine]] Basin that appeared to be younger than [[Tertiary]]{{efn|The Tertiary is a now obsolete geologic system/period spanning from 66 Ma to 2.6 Ma. It has no exact equivalent in the modern ICC, but is approximately equivalent to the merged Palaeogene and Neogene systems/periods.<ref name="Head_etal_2008">{{Cite journal |last1=Head |first1=Martin J. |last2=Gibbard |first2=Philip |last3=Salvador |first3=Amos |date=2008-06-01 |title=The Quaternary: its character and definition |journal=Episodes |language=en |volume=31 |issue=2 |pages=234–238 |doi=10.18814/epiiugs/2008/v31i2/009 |doi-access=free |issn=0705-3797}}</ref><ref name ="Gibbard_etal_2010">{{Cite journal |last1=Gibbard |first1=Philip L. |last2=Head |first2=Martin J. |last3=Walker |first3=Michael J. C. |last4=the Subcommission on Quaternary Stratigraphy |date=2010-01-20 |title=Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma |url=https://onlinelibrary.wiley.com/doi/10.1002/jqs.1338 |journal=Journal of Quaternary Science |language=en |volume=25 |issue=2 |pages=96–102 |doi=10.1002/jqs.1338 |bibcode=2010JQS....25...96G |issn=0267-8179}}</ref>|name=Tertiary|group=note}} rocks.<ref name="Desnoyers_1829">{{cite journal |last1=Desnoyers |first1=J. |title=Observations sur un ensemble de dépôts marins plus récents que les terrains tertiaires du bassin de la Seine, et constituant une formation géologique distincte; précédées d'un aperçu de la nonsimultanéité des bassins tertiares |journal=Annales des Sciences Naturelles |date=1829 |volume=16 |pages=171–214, 402–491 |url=https://www.biodiversitylibrary.org/item/29350#page/177/mode/1up |trans-title=Observations on a set of marine deposits [that are] more recent than the tertiary terrains of the Seine basin and [that] constitute a distinct geological formation; preceded by an outline of the non-simultaneity of tertiary basins |language=fr}} [https://www.biodiversitylibrary.org/item/29350#page/199/mode/1up From p. 193:] ''"Ce que je désirerais ... dont il faut également les distinguer."'' (What I would desire to prove above all is that the series of tertiary deposits continued – and even began in the more recent basins – for a long time, perhaps after that of the Seine had been completely filled, and that these later formations – ''Quaternary'' (1), so to say – should not retain the name of alluvial deposits any more than the true and ancient tertiary deposits, from which they must also be distinguished.)  However, on the very same page, Desnoyers abandoned the use of the term "Quaternary" because the distinction between Quaternary and Tertiary deposits wasn't clear.  From p. 193:  ''"La crainte de voir mal comprise ... que ceux du bassin de la Seine."'' (The fear of seeing my opinion in this regard be misunderstood or exaggerated, has made me abandon the word "quaternary", which at first I had wanted to apply to all deposits more recent than those of the Seine basin.)</ref>
|-
|[[Neogene]]
|{{Period span/brief|Neogene|1}}
|{{#expr:{{Period start|Neogene}}-{{Period end|Neogene}}}}
|Derived from Greek νέος (''néos'') 'new' and γενεά (''geneá'') 'genesis' or 'birth'.
|-
|[[Paleogene]]
|{{Period span/brief|Paleogene|1}}
|{{#expr:{{Period start|Paleogene}}-{{Period end|Paleogene}}}}
|Derived from Greek παλιός (''palaiós'') 'old' and γενεά (''geneá'') 'genesis' or 'birth'.
|-
|[[Cretaceous]]
|[[Tilde#Common use in English|~]]{{Period span/brief|Cretaceous|1}}
|~{{#expr:{{Period start|Cretaceous}}-{{Period end|Cretaceous}}}}
|Derived from ''Terrain Crétacé'' used in 1822 by [[Jean d'Omalius d'Halloy]] in reference to extensive beds of [[chalk]] within the [[Paris Basin]].<ref name="d'Halloy 1822">{{cite journal | author = d'Halloy, d'O., J.-J. | year = 1822 | title = Observations sur un essai de carte géologique de la France, des Pays-Bas, et des contrées voisines |trans-title=Observations on a trial geological map of France, the Low Countries, and neighboring countries | journal = Annales des Mines | volume = 7 | pages = 353–376 | url = https://books.google.com/books?id=c-ocAQAAIAAJ&pg=PA353}} From page 373: "La troisième, qui correspond à ce qu'on a déja appelé formation de la craie, sera désigné par le nom de terrain crétacé." (The third, which corresponds to what was already called the "chalk formation", will be designated by the name "chalky terrain".)</ref> Ultimately derived from [[Latin]] ''crēta'' 'chalk'.
|-
|[[Jurassic]]
|{{Period span/brief|Jurassic|1}}
|~{{#expr:{{Period start|Jurassic}}-{{Period end|Jurassic}}}}
|Named after the [[Jura Mountains]]. Originally used by [[Alexander von Humboldt]] as 'Jura Kalkstein' (Jura limestone) in 1799.<ref name="Humboldt_1799">{{Cite book |last=Humboldt |first=Alexander von |url=https://books.google.com/books?id=oZ5PAAAAcAAJ |title=Ueber die unterirdischen Gasarten und die Mittel ihren Nachtheil zu vermindern: ein Beytrag zur Physik der praktischen Bergbaukunde |date=1799 |publisher=Vieweg |language=de}}</ref> [[Alexandre Brongniart]] was the first to publish the term Jurassic in 1829.<ref name="Brogniart_1829">{{Cite book |last=Brongniart |first=Alexandre (1770-1847) Auteur du texte |url=https://gallica.bnf.fr/ark:/12148/bpt6k255061 |title=Tableau des terrains qui composent l'écorce du globe ou Essai sur la structure de la partie connue de la terre . Par Alexandre Brongniart,... |date=1829 |language=fr}}</ref><ref name="GTS2012_Jurassic">{{Citation |last1=Ogg |first1=J.G. |title=Jurassic |date=2012 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780444594259000263 |work=The Geologic Time Scale |pages=731–791 |publisher=Elsevier |language=en |doi=10.1016/b978-0-444-59425-9.00026-3 |isbn=978-0-444-59425-9 |access-date=2022-05-01 |last2=Hinnov |first2=L.A. |last3=Huang |first3=C.}}</ref>
|-
|[[Triassic]]
|{{Period span/brief|Triassic|1}}
|{{#expr:{{Period start|Triassic}}-{{Period end|Triassic}}}}
|From the ''Trias'' of [[Friedrich August von Alberti]] in reference to a trio of formations widespread in southern [[Germany]].
|-
|[[Permian]]
|{{Period span/brief|Permian|1}}
|{{#expr:{{Period start|Permian}}-{{Period end|Permian}}}}
|Named after the historical region of [[Perm Governorate|Perm]], [[Russian Empire]].<ref name="Murchison_1842">{{Cite book |last1=Murchison |url=https://books.google.com/books?id=MDoAAAAAQAAJ |title=On the Geological Structure of the Central and Southern Regions of Russia in Europe, and of the Ural Mountains |last2=Murchison |first2=Sir Roderick Impey |last3=Verneuil |last4=Keyserling |first4=Graf Alexander |date=1842 |publisher=Print. by R. and J.E. Taylor |language=en}}</ref>
|-
|[[Carboniferous]]
|{{Period span/brief|Carboniferous|1}}
|{{#expr:{{Period start|Carboniferous}}-{{Period end|Carboniferous}}}}
|Means 'coal-bearing', from the [[Latin]] carbō (''coal'') and ferō (''to bear, carry'').<ref name="Phillips_1835">{{Cite book |last=Phillips |first=John |url=https://books.google.com/books?id=-7-ZqIkYBOMC&pg=PA1 |title=Illustrations of the Geology of Yorkshire: Or, A Description of the Strata and Organic Remains: Accompanied by a Geological Map, Sections and Plates of the Fossil Plants and Animals ... |date=1835 |publisher=J. Murray |language=en}}</ref>
|-
|[[Devonian]]
|{{Period span/brief|Devonian|1}}
|{{#expr:{{Period start|Devonian}}-{{Period end|Devonian}}}}
|Named after [[Devon]], England.<ref name="Sedgwick_1840">{{Cite journal |last1=Sedgwick |first1=A. |last2=Murchison |first2=R. I. |date=1840-01-01 |title=XLIII.--On the Physical Structure of Devonshire, and on the Subdivisions and Geological Relations of its older stratified Deposits, &c. |url=https://books.google.com/books?id=QknWzPRnVRQC&pg=PA701 |journal=Transactions of the Geological Society of London |language=en |volume=s2-5 |issue=3 |pages=633–703 |doi=10.1144/transgslb.5.3.633 |s2cid=128475487 |issn=2042-5295}}</ref>
|-
|[[Silurian]]
|{{Period span/brief|Silurian|1}}
|{{#expr:{{Period start|Silurian}}-{{Period end|Silurian}}}}
|Named after the [[Celts|Celtic]] tribe, the [[Silures]].<ref name ="Murchison_1835">{{Cite journal |last=Murchison |first=Roderick Impey |date=1835 |title=VII. On the silurian system of rocks |url=https://www.tandfonline.com/doi/full/10.1080/14786443508648654 |journal=The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science |language=en |volume=7 |issue=37 |pages=46–52 |doi=10.1080/14786443508648654 |issn=1941-5966}}</ref>
|-
|[[Ordovician]]
|{{Period span/brief|Ordovician|1}}
|{{#expr:{{Period start|Ordovician}}-{{Period end|Ordovician}}}}
|Named after the Celtic tribe, [[Ordovices]].<ref name="Lapworth_1879">{{Cite journal |last=Lapworth |first=Charles |date=1879 |title=I.—On the Tripartite Classification of the Lower Palæozoic Rocks |url=https://www.cambridge.org/core/product/identifier/S0016756800156560/type/journal_article |journal=[[Geological Magazine]] |language=en |volume=6 |issue=1 |pages=1–15 |doi=10.1017/S0016756800156560 |bibcode=1879GeoM....6....1L |s2cid=129165105 |issn=0016-7568}}</ref><ref>{{Cite journal |last=Bassett |first=Michael G. |title=100 Years of Ordovician Geology |date=1979-06-01 |journal=Episodes |language=en |volume=2 |issue=2 |pages=18–21 |doi=10.18814/epiiugs/1979/v2i2/003 |issn=0705-3797|doi-access=free }}</ref>
|-
|[[Cambrian]]
|{{Period span/brief|Cambrian|1}}
|{{#expr:{{Period start|Cambrian}}-{{Period end|Cambrian}}}}
|Named for [[Cambria]], a [[latin]]ised form of the Welsh name for [[Wales]], ''Cymru''.<ref>{{cite EB1911|wstitle=Cambria}}</ref>
|-
|[[Ediacaran]]
|{{Period span/brief|Ediacaran|1}}
|~{{#expr:{{Period start|Ediacaran}}-{{Period end|Ediacaran}}}}
|Named for the [[Ediacara Hills]]. Ediacara is possibly a corruption of [[Kuyani]] 'Yata Takarra' 'hard or stony ground'.<ref name="Butcher_2004">{{cite web |last=Butcher |first=Andy |date=26 May 2004 |title=Re: Ediacaran |url=http://listserv.linguistlist.org/cgi-bin/wa?A2=ind0405&L=australian-linguistics-l&D=1&P=264 |url-status=dead |archive-url=https://web.archive.org/web/20071023012434/http://listserv.linguistlist.org/cgi-bin/wa?A2=ind0405&L=australian-linguistics-l&D=1&P=264 |archive-date=23 October 2007 |access-date=19 July 2011 |work=LISTSERV 16.0 - AUSTRALIAN-LINGUISTICS-L Archives}}</ref><ref name="AHD_Ediacara_Fossil_Site">{{cite web |title=Place Details: Ediacara Fossil Site – Nilpena, Parachilna, SA, Australia |url=http://www.environment.gov.au/cgi-bin/ahdb/search.pl?mode=place_detail;place_id=105880 |url-status=live |archive-url=https://web.archive.org/web/20110603074010/http://www.environment.gov.au/cgi-bin/ahdb/search.pl?mode=place_detail;place_id=105880 |archive-date=3 June 2011 |access-date=19 July 2011 |work=Australian Heritage Database |publisher=Commonwealth of Australia |department=Department of Sustainability, Environment, Water, Population and Communities |df=dmy-all}}</ref>
|-
|[[Cryogenian]]
|{{Period span/brief|Cryogenian|1}}
|~{{#expr:{{Period start|Cryogenian}}-{{Period end|Cryogenian}}}}
|From Greek κρύος (''krýos'') 'cold' and γένεσις (''génesis'') 'birth'.<ref name="GTS2012_Precambrian" />
|-
|[[Tonian]]
|{{Period span/brief|Tonian|1}}
|~{{#expr:{{Period start|Tonian}}-{{Period end|Tonian}}}}
|From Greek τόνος (''tónos'') 'stretch'.<ref name="GTS2012_Precambrian" />
|-
|[[Stenian]]
|{{Period span/brief|Stenian|1}}
|{{#expr:{{Period start|Stenian}}-{{Period end|Stenian}}}}
|From Greek στενός (''stenós'') 'narrow'.<ref name="GTS2012_Precambrian" />
|-
|[[Ectasian]]
|{{Period span/brief|Ectasian|1}}
|{{#expr:{{Period start|Ectasian}}-{{Period end|Ectasian}}}}
|From Greek ἔκτᾰσῐς (''éktasis'') 'extension'.<ref name="GTS2012_Precambrian" />
|-
|[[Calymmian]]
|{{Period span/brief|Calymmian|1}}
|{{#expr:{{Period start|Calymmian}}-{{Period end|Calymmian}}}}
|From Greek κάλυμμᾰ (''kálumma'') 'cover'.<ref name="GTS2012_Precambrian" />
|-
|[[Statherian]]
|{{Period span/brief|Statherian|1}}
|{{#expr:{{Period start|Statherian}}-{{Period end|Statherian}}}}
|From Greek σταθερός (''statherós'') 'stable'.<ref name="GTS2012_Precambrian" />
|-
|[[Orosirian]]
|{{Period span/brief|Orosirian|1}}
|{{#expr:{{Period start|Orosirian}}-{{Period end|Orosirian}}}}
|From Greek ὀροσειρά (''oroseirá'') 'mountain range'.<ref name="GTS2012_Precambrian" />
|-
|[[Rhyacian]]
|{{Period span/brief|Rhyacian|1}}
|{{#expr:{{Period start|Rhyacian}}-{{Period end|Rhyacian}}}}
|From Greek ῥύαξ (''rhýax'') 'stream of lava'.<ref name="GTS2012_Precambrian" />
|-
|[[Siderian]]
|{{Period span/brief|Siderian|1}}
|{{#expr:{{Period start|Siderian}}-{{Period end|Siderian}}}}
|From Greek σίδηρος (''sídēros'') '[[iron]]'.<ref name="GTS2012_Precambrian" />
|}
{| class="wikitable mw-collapsible" style = "margin-left: auto; margin-right: auto; border: none;"
|+Time span and etymology of geologic series/epoch names
!Name
!Time span
!Duration (million years)
!Etymology of name
|-
|[[Holocene]]
|{{Period span/brief|Holocene|3}}
|{{#expr:{{Period start|Holocene}}-{{Period end|Holocene}}}}
|From Greek ὅλος (''hólos'') 'whole' and καινός (''kainós'') 'new'
|-
|[[Pleistocene]]
|{{Period span/brief|Pleistocene|3}}
|{{#expr:{{Period start|Pleistocene}}-{{Period end|Pleistocene}}}}
|Coined in the early 1830s from Greek πλεῖστος (''pleîstos'') 'most' and καινός (''kainós'') 'new'
|-
|[[Pliocene]]
|{{Period span/brief|Pliocene|2}}
|{{#expr:{{Period start|Pliocene}}-{{Period end|Pliocene}}}}
|Coined in the early 1830s from Greek πλείων (''pleíōn'') 'more' and καινός (''kainós'') 'new'
|-
|[[Miocene]]
|{{Period span/brief|Miocene|2}}
|{{#expr:{{Period start|Miocene}}-{{Period end|Miocene}}}}
|Coined in the early 1830s from Greek μείων (''meíōn'') 'less' and καινός (''kainós'') 'new'
|-
|[[Oligocene]]
|{{Period span/brief|Oligocene|2}}
|{{#expr:{{Period start|Oligocene}}-{{Period end|Oligocene}}}}
|Coined in the 1850s from Greek ὀλίγος (''olígos'') 'few' and καινός (''kainós'') 'new'
|-
|[[Eocene]]
|{{Period span/brief|Eocene|2}}
|{{#expr:{{Period start|Eocene}}-{{Period end|Eocene}}}}
|Coined in the early 1830s from Greek ἠώς (''ēōs'') 'dawn' and καινός (''kainós'') 'new', referring to the dawn of modern life during this epoch
|-
|[[Paleocene]]
|{{Period span/brief|Paleocene|2}}
|{{#expr:{{Period start|Paleocene}}-{{Period end|Paleocene}}}}
|Coined by [[Wilhelm Philippe Schimper]] in 1874 as a portmanteau of paleo- + Eocene, but on the surface from Greek παλαιός (''palaios'') 'old' and καινός (''kainós'') 'new'
|-
|[[Upper Cretaceous]]
|{{Period span/brief|Upper Cretaceous|2}}
|{{#expr:{{Period start|Upper Cretaceous}}-{{Period end|Upper Cretaceous}}}}
|rowspan="2" |See [[Cretaceous]]
|-
|[[Lower Cretaceous]]
|{{Period span/brief|Lower Cretaceous|2}}
|{{#expr:{{Period start|Lower Cretaceous}}-{{Period end|Lower Cretaceous}}}}
|-
|[[Upper Jurassic]]<br />
|{{Period span/brief|Upper Jurassic|2}}
|{{#expr:{{Period start|Upper Jurassic}}-{{Period end|Upper Jurassic}}}}
|rowspan="3" |See [[Jurassic]]
|-
|[[Middle Jurassic]]
|{{Period span/brief|Middle Jurassic|2}}
|{{#expr:{{Period start|Middle Jurassic}}-{{Period end|Middle Jurassic}}}}
|-
|[[Lower Jurassic]]<br />
|{{Period span/brief|Lower Jurassic|2}}
|{{#expr:{{Period start|Lower Jurassic}}-{{Period end|Lower Jurassic}}}}
|-
|[[Upper Triassic]]
|{{Period span/brief|Upper Triassic|2}}
|{{#expr:{{Period start|Upper Triassic}}-{{Period end|Upper Triassic}}}}
|rowspan="3" |See [[Triassic]]
|-
|[[Middle Triassic]]<br />
|{{Period span/brief|Middle Triassic|2}}
|{{#expr:{{Period start|Middle Triassic}}-{{Period end|Middle Triassic}}}}
|-
|[[Lower Triassic]]
|{{Period span/brief|Lower Triassic|2}}
|{{#expr:{{Period start|Lower Triassic}}-{{Period end|Lower Triassic}}}}
|-
|[[Lopingian]]
|{{Period span/brief|Lopingian|2}}
|{{#expr:{{Period start|Lopingian}}-{{Period end|Lopingian}}}}
|Named for [[Leping|Loping]], China, an anglicization of Mandarin 乐平 (''lèpíng'') 'peaceful music'
|-
|[[Guadalupian]]
|{{Period span/brief|Guadalupian|2}}
|{{#expr:{{Period start|Guadalupian}}-{{Period end|Guadalupian}}}}
|Named for the [[Guadalupe Mountains]] of the American Southwest, ultimately from Arabic وَادِي ٱل (''wādī al'') 'valley of the' and Latin ''lupus'' 'wolf' via Spanish
|-
|[[Cisuralian]]
|{{Period span/brief|Cisuralian|2}}
|{{#expr:{{Period start|Cisuralian}}-{{Period end|Cisuralian}}}}
|From Latin ''cis-'' (before) + Russian Урал (''Ural''), referring to the western slopes of the [[Ural Mountains]]
|-
|[[Pennsylvanian (geology)|Upper Pennsylvanian]]
|{{Period span/brief|Upper Pennsylvanian|2}}
|{{#expr:{{Period start|Upper Pennsylvanian}}-{{Period end|Upper Pennsylvanian}}}}
|rowspan="3" |Named for the US state of [[Pennsylvania]], from [[William Penn]] + Latin ''silvanus'' (forest) + -ia by analogy to Transylvania
|-
|[[Pennsylvanian (geology)|Middle Pennsylvanian]]
|{{Period span/brief|Middle Pennsylvanian|2}}
|{{#expr:{{Period start|Middle Pennsylvanian}}-{{Period end|Middle Pennsylvanian}}}}
|-
|[[Pennsylvanian (geology)|Lower Pennsylvanian]]
|{{Period span/brief|Lower Pennsylvanian|2}}
|{{#expr:{{Period start|Lower Pennsylvanian}}-{{Period end|Lower Pennsylvanian}}}}
|-
|[[Mississippian (geology)|Upper Mississippian]]
|{{Period span/brief|Upper Mississippian|2}}
|{{#expr:{{Period start|Upper Mississippian}}-{{Period end|Upper Mississippian}}}}
|rowspan="3" |Named for the [[Mississippi River]], from Ojibwe ᒥᐦᓯᓰᐱ (''misi-ziibi'') 'great river'
|-
|[[Mississippian (geology)|Middle Mississippian]]
|{{Period span/brief|Middle Mississippian|2}}
|{{#expr:{{Period start|Middle Mississippian}}-{{Period end|Middle Mississippian}}}}
|-
|[[Mississippian (geology)|Lower Mississippian]]
|{{Period span/brief|Lower Mississippian|2}}
|{{#expr:{{Period start|Lower Mississippian}}-{{Period end|Lower Mississippian}}}}
|-
|[[Upper Devonian]]
|{{Period span/brief|Upper Devonian|2}}
|{{#expr:{{Period start|Upper Devonian}}-{{Period end|Upper Devonian}}}}
|rowspan="3" |See [[Devonian]]
|-
|[[Middle Devonian]]
|{{Period span/brief|Middle Devonian|2}}
|{{#expr:{{Period start|Middle Devonian}}-{{Period end|Middle Devonian}}}}
|-
|[[Lower Devonian]]
|{{Period span/brief|Lower Devonian|2}}
|{{#expr:{{Period start|Lower Devonian}}-{{Period end|Lower Devonian}}}}
|-
|[[Pridoli Epoch|Pridoli]]
|{{Period span/brief|Pridoli|2}}
|{{#expr:{{Period start|Pridoli}}-{{Period end|Pridoli}}}}
|Named for the Homolka a Přídolí nature reserve near [[Prague]], Czechia
|-
|[[Ludlow Epoch|Ludlow]]
|{{Period span/brief|Ludlow|2}}
|{{#expr:{{Period start|Ludlow}}-{{Period end|Ludlow}}}}
|Named after [[Ludlow]], England
|-
|[[Wenlock Epoch|Wenlock]]
|{{Period span/brief|Wenlock|2}}
|{{#expr:{{Period start|Wenlock}}-{{Period end|Wenlock}}}}
|Named for the [[Wenlock Edge]] in [[Shropshire]], England
|-
|[[Llandovery Epoch|Llandovery]]
|{{Period span/brief|Llandovery|2}}
|{{#expr:{{Period start|Llandovery}}-{{Period end|Llandovery}}}}
|Named after [[Llandovery]], Wales
|-
|[[Upper Ordovician]]
|{{Period span/brief|Upper Ordovician|2}}
|{{#expr:{{Period start|Upper Ordovician}}-{{Period end|Upper Ordovician}}}}
|rowspan="3" |See [[Ordovician]]
|-
|[[Middle Ordovician]]
|{{Period span/brief|Middle Ordovician|2}}
|{{#expr:{{Period start|Middle Ordovician}}-{{Period end|Middle Ordovician}}}}
|-
|[[Lower Ordovician]]
|{{Period span/brief|Lower Ordovician|2}}
|{{#expr:{{Period start|Lower Ordovician}}-{{Period end|Lower Ordovician}}}}
|-
|[[Furongian]]
|{{Period span/brief|Furongian|2}}
|{{#expr:{{Period start|Furongian}}-{{Period end|Furongian}}}}
|From Mandarin 芙蓉 (''fúróng'') 'lotus', referring to the state symbol of [[Hunan]]
|-
|[[Miaolingian]]
|{{Period span/brief|Cambrian series 3|2}}
|{{#expr:{{Period start|Cambrian series 3}}-{{Period end|Cambrian series 3}}}}
|Named for the {{ill|Miao Ling|zh|苗嶺山脈}} mountains of [[Guizhou]], Mandarin for 'sprouting peaks'
|-
|[[Cambrian Series 2]] (informal)
|{{Period span/brief|Cambrian series 2|2}}
|{{#expr:{{Period start|Cambrian series 2}}-{{Period end|Cambrian series 2}}}}
|See [[Cambrian]]
|-
|[[Terreneuvian]]
|{{Period span/brief|Terreneuvian|2}}
|{{#expr:{{Period start|Terreneuvian}}-{{Period end|Terreneuvian}}}}
|Named for [[Terre-Neuve (New France)|Terre-Neuve]], a French [[calque]] of [[Newfoundland (island)|Newfoundland]]
|}