Editing Cycad (section)

==Fossil record==

[[File:Bowenia spectabilis.JPG|thumb|''[[Bowenia spectabilis]]'' : plant with single frond in the Daintree rainforest, north-east Queensland]]

[[File:Cycad cone.jpg|upright|thumb|Leaves and strobilus of ''[[Encephalartos sclavoi]]'']]

The oldest probable cycad foliage is known from the latest Carboniferous-Early Permian of South Korea and China, such as ''[[Crossozamia]]''. Unambiguous fossils of cycads are known from the Early-Middle Permian onwards.<ref>{{Cite journal |last1=Spiekermann |first1=Rafael |last2=Jasper |first2=André |last3=Siegloch |first3=Anelise Marta |last4=Guerra-Sommer |first4=Margot |last5=Uhl |first5=Dieter |date=June 2021 |title=Not a lycopsid but a cycad-like plant: ''Iratinia australis'' gen. nov. et sp. nov. from the Irati Formation, Kungurian of the Paraná Basin, Brazil |journal=Review of Palaeobotany and Palynology |language=en |volume=289 |pages=104415 |doi=10.1016/j.revpalbo.2021.104415 |bibcode=2021RPaPa.28904415S |s2cid=233860955}}</ref> Cycads were generally uncommon during the Permian.<ref>{{Cite journal |last=Gomankov |first=A. V. |date=June 2022 |title=Cycads in the Permian of thе Subangara Region  |journal=Paleontological Journal |language=en |volume=56 |issue=3 |pages=317–326 |doi=10.1134/S0031030122030066 |bibcode=2022PalJ...56..317G |s2cid=249627815 |issn=0031-0301}}</ref> The two living cycad families are thought to have split from each other sometime between the Jurassic<ref name="Nagalingum2011" /> and Carboniferous.<ref name=":0">{{Cite journal |last1=Coiro |first1=Mario |last2=Allio |first2=Rémi |last3=Mazet |first3=Nathan |last4=Seyfullah |first4=Leyla J. |last5=Condamine |first5=Fabien L. |date=2023-06-11 |title=Reconciling fossils with phylogenies reveals the origin and macroevolutionary processes explaining the global cycad biodiversity |journal=New Phytologist |volume=240 |issue=4 |pages=1616–1635 |language=en |doi=10.1111/nph.19010 |pmid=37302411 |issn=0028-646X|doi-access=free |pmc=10953041 |bibcode=2023NewPh.240.1616C }}</ref> Cycads are thought to have reached their apex of diversity during the Mesozoic.<ref>{{Cite journal |last1=Coiro |first1=Mario |last2=Seyfullah |first2=Leyla Jean |date=2024-03-14 |title=Disparity of cycad leaves dispels the living fossil metaphor |journal=Communications Biology |language=en |volume=7 |issue=1 |page=328 |doi=10.1038/s42003-024-06024-9 |issn=2399-3642 |pmc=10940627 |pmid=38485767}}</ref> Although the Mesozoic is sometimes called the "Age of Cycads,"  some other groups of distantly related extinct seed plants with similar foliage, such as [[Bennettitales]] and [[Nilssonia (plant)|Nilssoniales]] were considerably more abundant than cycads during the Mesozoic, with true cycads being minor components of Mesozoic vegetation.<ref name="Coiro-2017">{{Cite journal |last1=Coiro |first1=Mario |last2=Pott |first2=Christian |date=December 2017 |title=Eobowenia gen. nov. from the Early Cretaceous of Patagonia: indication for an early divergence of Bowenia? |journal=BMC Evolutionary Biology |language=en |volume=17 |issue=1 |pages=97 |doi=10.1186/s12862-017-0943-x |issn=1471-2148 |pmc=5383990 |pmid=28388891 |doi-access=free |bibcode=2017BMCEE..17...97C }}</ref> The oldest records of the modern genus ''Cycas'' are from the Paleogene of East Asia.<ref>{{Cite journal |last1=Liu |first1=Jian |last2=Lindstrom |first2=Anders J |last3=Marler |first3=Thomas E |last4=Gong |first4=Xun |date=2022-01-28 |title=Not that young: combining plastid phylogenomic, plate tectonic and fossil evidence indicates a Palaeogene diversification of Cycadaceae |journal=Annals of Botany |language=en |volume=129 |issue=2 |pages=217–230 |doi=10.1093/aob/mcab118 |doi-access=free |issn=0305-7364 |pmc=8796677 |pmid=34520529}}</ref> Fossils assignable to Zamiaceae are known from the Cretaceous,<ref name="Coiro-2017" /> with fossils assignable to living genera of the family known from the Cenozoic.<ref name="Condamine-2015" />

[[File:Fossilized cycad New York Botanical Garden.jpg|upright|thumb|Petrified cycad fossil, New York Botanical Garden]]