Corystospermaceae

{{Short description|Extinct family of seed ferns}} {{Automatic taxobox | fossil_range = {{fossilrange|Late Permian|Early Jurassic|latest=50}} | image = Bulgo Sandstone biota.jpg | image_caption = Reconstruction of the ''Dicroidium'' plant (top right) in an Early Triassic Australian landscape. Art by Michael Rothman | parent_authority = Petriella, 1981 | display_parents = 2 | taxon = Corystospermaceae | authority = Thomas, 1933 | subdivision_ranks = Genera | subdivision = See text | synonyms = *'''Ptilozamitaceae''' Němejc, 1950 *'''Umkomasiaceae''' Petriella, 1981 *'''Zuberiaceae''' Němejc, 1968 }}

'''Corystosperms''' are a group of extinct seed plants (often referred to as "seed ferns") belonging to the family '''Corystospermaceae''' (also called '''Umkomasiaceae''') assigned to the order '''Corystospermales'''<ref>{{Cite journal |last1=Abu Hamad |first1=A. |last2=Blomenkemper |first2=P. |last3=Kerp |first3=H. |last4=Bomfleur |first4=B. |date=December 2017 |title=Dicroidium bandelii sp. nov. (corystospermalean foliage) from the Permian of Jordan |url=http://link.springer.com/10.1007/s12542-017-0384-2 |journal=PalZ |volume=91 |issue=4 |pages=641–648 |doi=10.1007/s12542-017-0384-2 |bibcode=2017PalZ...91..641A |s2cid=90520943 |issn=0031-0220|url-access=subscription }}</ref> or '''Umkomasiales'''.<ref name=":4">{{Cite book |last=Doweld |first=Alexander B. |url=https://books.google.com/books?id=MBAIAf3OAPcC |title=Prosyllabus Tracheophytorum: Tentamen systematis plantarum vascularium |publisher=GEOS |year=2001 |location=Moscow |language=EN, RU}}</ref><ref name=":0" /> They were first described based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa.<ref>{{cite journal | title=On some pteridospermous plants from the Mesozoic rocks of South Africa | author=Thomas, H.H. | journal=Philosophical Transactions of the Royal Society B | year=1933 | volume=222 | issue=483–493 | pages=193–265 | doi=10.1098/rstb.1932.0016 | doi-access=free }} </ref> Corystosperms are typified by a group of plants that bore forked ''Dicroidium'' leaves, ''Umkomasia'' cupulate ovulate structures and ''Pteruchus'' pollen organs, which grew as trees that were widespread over Gondwana during the Middle and Late Triassic. Other fossil Mesozoic seed plants with similar leaf and/or reproductive structures have also sometimes been included within the "corystosperm" concept ''sensu lato'', such as the "doyleoids" from the Early Cretaceous of North America and Asia.<ref name=":0">{{Cite journal |last1=Shi |first1=Gongle |last2=Herrera |first2=Fabiany |last3=Herendeen |first3=Patrick S. |last4=Clark |first4=Elizabeth G. |last5=Crane |first5=Peter R. |date=2022-12-31 |title=Silicified cupulate seed-bearing structures from the Early Cretaceous of eastern Inner Mongolia, China: rethinking the corystosperm concept |url=https://www.tandfonline.com/doi/full/10.1080/14772019.2022.2133644 |journal=Journal of Systematic Palaeontology |volume=20 |issue=1 |pages=1–33 |doi=10.1080/14772019.2022.2133644 |s2cid=253562726 |issn=1477-2019|url-access=subscription }}</ref> A potential corystosperm ''sensu lato'', the leaf genus ''Komlopteris'', is known from the Eocene of Tasmania, around 53-50 million years old, over 10 million years after the Cretaceous–Paleogene extinction event.<ref name=":2">{{Cite journal |last1=McLoughlin |first1=Stephen |last2=Carpenter |first2=Raymond J. |last3=Jordan |first3=Gregory J. |last4=Hill |first4=Robert S. |date=2008 |title=Seed ferns survived the end-Cretaceous mass extinction in Tasmania |url=https://bsapubs.onlinelibrary.wiley.com/doi/abs/10.3732/ajb.95.4.465 |journal=American Journal of Botany |volume=95 |issue=4 |pages=465–471 |doi=10.3732/ajb.95.4.465 |pmid=21632371 |issn=1537-2197}}</ref>

==Description== Classic Umkomasiaceae have helmet-like cupules around ovules born in complex large branching structures (''Umkomasia''). The pollen organ (''Pteruchus'') has numerous cigar-shaped pollen sacs hanging from epaulette-like blades, again in complex branching structures.

The architecture and size of ''Dicroidium'' leaves is highly variable, going from simple to tripinnate, to needle-like to lobed or dissected leaflets, however, all leaves are united by being bifurcated at the base.<ref name=":1">{{Citation |last1=Bomfleur |first1=Benjamin |title=Polar Regions of the Mesozoic–Paleogene Greenhouse World as Refugia for Relict Plant Groups |date=2018 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780128130124000243 |work=Transformative Paleobotany |pages=593–611 |access-date=2020-11-12 |publisher=Elsevier |doi=10.1016/b978-0-12-813012-4.00024-3 |isbn=978-0-12-813012-4 |last2=Blomenkemper |first2=Patrick |last3=Kerp |first3=Hans |last4=McLoughlin |first4=Stephen}}</ref>

The ''Dicroidium'' plant (which bore ''Dicroidium'' leaves, ''Umkomasia'' seed bearing structures and ''Pteruchus'' pollen organs) is thought to have grown as large trees, with trunks at least {{Convert|10|m|ft}} tall and over {{Convert|50|cm|in}} wide.<ref name=":22">{{Cite web |last1=Mays |first1=Chris |last2=McLoughlin |first2=Stephen |date=2020-02-25 |title=Caught between two mass extinctions: The rise and fall of Dicroidium |url=https://depositsmag.com/2020/02/25/caught-between-two-mass-extinctions-the-rise-and-fall-of-dicroidium/ |access-date=2023-09-23 |website=Deposits Mag }}</ref> Some other possible corystosperms like ''Pachypteris'' may have grown as shrubs.<ref>{{Cite journal |last1=Barbacka |first1=Maria |last2=Górecki |first2=Artur |last3=Pacyna |first3=Grzegorz |last4=Pieńkowski |first4=Grzegorz |last5=Philippe |first5=Marc |last6=Bóka |first6=Károly |last7=Ziaja |first7=Jadwiga |last8=Jarzynka |first8=Agata |last9=Qvarnström |first9=Martin |last10=Niedźwiedzki |first10=Grzegorz |date=March 2022 |editor-last=Bomfleur |editor-first=Benjamin |title=Early Jurassic coprolites: insights into palaeobotany and the feeding behaviour of dinosaurs |url=https://onlinelibrary.wiley.com/doi/10.1002/spp2.1425 |journal=Papers in Palaeontology |volume=8 |issue=2 |doi=10.1002/spp2.1425 |issn=2056-2799|url-access=subscription }}</ref>

== Evolutionary history == The oldest fossils of corystosperms, belonging to ''Dicroidium, Pteruchus'' and ''Umkomasia'' date to the Late Permian in the low-latitudes of eastern Gondwana, including the Umm Irna Formation of Jordan, as well as the Indian subcontinent,<ref name="linkinghub.elsevier.com">{{Cite journal |last1=Blomenkemper |first1=Patrick |last2=Kerp |first2=Hans |last3=Abu Hamad |first3=Abdalla |last4=Bomfleur |first4=Benjamin |date=July 2020 |title=Contributions towards whole-plant reconstructions of Dicroidium plants (Umkomasiaceae) from the Permian of Jordan |url=https://linkinghub.elsevier.com/retrieve/pii/S0034666719303252 |journal=Review of Palaeobotany and Palynology |volume=278 |article-number=104210 |doi=10.1016/j.revpalbo.2020.104210|bibcode=2020RPaPa.27804210B |s2cid=216248477 |url-access=subscription }}</ref><ref>{{Cite journal |author1=Patrick Blomenkemper |author2=Hans Kerp |author3=Abdalla Abu Hamad |author4=William A. DiMichele |author5=Benjamin Bomfleur |year=2018 |title=A hidden cradle of plant evolution in Permian tropical lowlands |journal=Science |volume=362 |issue=6421 |pages=1414–1416 |bibcode=2018Sci...362.1414B |doi=10.1126/science.aau4061 |pmid=30573628 |doi-access=free}}</ref><ref>{{Cite journal |last1=Schneebeli-Hermann |first1=Elke |last2=Kürschner |first2=Wolfram M. |last3=Kerp |first3=Hans |last4=Bomfleur |first4=Benjamin |last5=Hochuli |first5=Peter A. |last6=Bucher |first6=Hugo |last7=Ware |first7=David |last8=Roohi |first8=Ghazala |date=April 2015 |title=Vegetation history across the Permian–Triassic boundary in Pakistan (Amb section, Salt Range) |url=https://linkinghub.elsevier.com/retrieve/pii/S1342937X13003717 |journal=Gondwana Research |volume=27 |issue=3 |pages=911–924 |bibcode=2015GondR..27..911S |doi=10.1016/j.gr.2013.11.007}}</ref> though possible pollen belonging to the group is also known from the Late Permian of South Africa.<ref>{{Cite journal |last1=Gastaldo |first1=Robert A. |last2=Bamford |first2=Marion K. |date=August 2023 |title=The influence of taphonomy and time on the paleobotanical record of the Permian–Triassic transition of the Karoo basin (and elsewhere) |journal=Journal of African Earth Sciences |volume=204 |article-number=104960 |doi=10.1016/j.jafrearsci.2023.104960|bibcode=2023JAfES.20404960G |doi-access=free }}</ref> During the Middle-Late Triassic, ''Dicroidium'' bearing corystosperms were widespread and dominant trees over temperate areas of southern Gondwana (including the Indian subcontinent, South America, Southern Africa, Antarctica, Australia and New Zealand) including wetland and forest environments, where they formed part of the canopy vegetation.<ref name=":1" /><ref name="linkinghub.elsevier.com"/> ''Dicroidium-''bearing corystosperm ecosystems collapsed as a result of the end-Triassic extinction event. Late surviving ''Dicroidium''-bearing corystosperms are known from the Early Jurassic (Sinemurian) of East Antarctica.<ref name=":1" /> During the Jurassic, the possible corystosperms ''Pachypteris'' and ''Komlopteris'' were widespread over both hemispheres,<ref name=":3">{{Cite journal |last1=Slodownik |first1=Miriam |last2=Hill |first2=Robert S. |last3=McLoughlin |first3=Stephen |date=October 2023 |title=Komlopteris: A persistent lineage of post-Triassic corystosperms in Gondwana |journal=Review of Palaeobotany and Palynology |volume=317 |article-number=104950 |doi=10.1016/j.revpalbo.2023.104950|bibcode=2023RPaPa.31704950S |doi-access=free }}</ref> with ''Komlopteris'' surviving in the Southern Hemisphere through the Cretaceous and into the early Eocene in Tasmania, making it the last surviving "seed fern" in the fossil record.<ref name=":2" /><ref name=":3" /> A group of plants with corystosperm-like reproductive structures, either considered corystosperms or as belonging to the separate order Doyleales, were present in North America and Asia during the Early Cretaceous,<ref name=":0" /> with records of the group possibly extending back as far as the Early Jurassic.<ref>{{Cite journal |last1=Elgorriaga |first1=Andres |last2=Atkinson |first2=Brian A. |date=July 2023 |title=Zirabia cylindrica comb. nov. provides evidence of Doyleales in the Jurassic |url=https://bsapubs.onlinelibrary.wiley.com/doi/10.1002/ajb2.16182 |journal=American Journal of Botany |volume=110 |issue=7 |article-number=e16182 |doi=10.1002/ajb2.16182 |pmid=37272508 |s2cid=259074746 |issn=0002-9122|url-access=subscription }}</ref>

== List of genera ==

* ''Umkomasia'' ovulate structures * ''Pteruchus'' pollen organs * ''Dicroidium'' leaves * ''Johnstonia'' leaves * ''Komlopteris''? leaves * ''Kurtziana''? leaves * ''Pachypteris''? leaves * ''Xylopteris'' leaves * ''Antarcticoxylon'' wood * ''Kyklyxylon'' wood * ''Rhexoxylon'' wood * "Doyleoids" (sometimes included) ** ''Doylea'' ovulate structures ** ''Jarudia'' ovulate structures ** ''Tevshiingovia'' ovulate structures ** ''Zirabia'' ovulate structures

== Relationships to other seed plants ==

The relationships of corystosperms to other seed plants are contentious.<ref>{{Cite journal |last1=Taylor |first1=Edith L. |last2=Taylor |first2=Thomas N. |date=January 2009 |title=Seed ferns from the late Paleozoic and Mesozoic: Any angiosperm ancestors lurking there? |url=https://bsapubs.onlinelibrary.wiley.com/doi/10.3732/ajb.0800202 |journal=American Journal of Botany |volume=96 |issue=1 |pages=237–251 |doi=10.3732/ajb.0800202 |pmid=21628187 |issn=0002-9122|url-access=subscription }}</ref> It has been suggested that some "peltasperms" may be closely related to corystosperms.<ref>{{Cite journal |last1=Elgorriaga |first1=Andrés |last2=Escapa |first2=Ignacio H. |last3=Cúneo |first3=N. Rubén |date=July 2019 |title=Relictual Lepidopteris (Peltaspermales) from the Early Jurassic Cañadón Asfalto Formation, Patagonia, Argentina |url=https://www.journals.uchicago.edu/doi/10.1086/703461 |journal=International Journal of Plant Sciences |volume=180 |issue=6 |pages=578–596 |doi=10.1086/703461 |s2cid=195435840 |issn=1058-5893|url-access=subscription }}</ref> A 2016 paper suggested that they may be closely related to Ginkgoales,<ref>{{Cite journal |last1=Shi |first1=Gongle |last2=Leslie |first2=Andrew B. |last3=Herendeen |first3=Patrick S. |last4=Herrera |first4=Fabiany |last5=Ichinnorov |first5=Niiden |last6=Takahashi |first6=Masamichi |last7=Knopf |first7=Patrick |last8=Crane |first8=Peter R. |date=June 2016 |title=Early Cretaceous Umkomasia from Mongolia: implications for homology of corystosperm cupules |journal=New Phytologist |volume=210 |issue=4 |pages=1418–1429 |doi=10.1111/nph.13871 |pmid=26840646 |issn=0028-646X|doi-access=free }}</ref> while a 2021 study suggested that based on the structure of their ovulate organs, corystosperms might form part of the "Anthophyte" clade more closely related to flowering plants than to living gymnosperms, alongside the Petriellales, Caytoniales, and glossopterids.<ref>{{Cite journal |last1=Shi |first1=Gongle |last2=Herrera |first2=Fabiany |last3=Herendeen |first3=Patrick S. |last4=Clark |first4=Elizabeth G. |last5=Crane |first5=Peter R. |date=2021-06-10 |title=Mesozoic cupules and the origin of the angiosperm second integument |url=https://www.nature.com/articles/s41586-021-03598-w |journal=Nature |volume=594 |issue=7862 |pages=223–226 |doi=10.1038/s41586-021-03598-w |pmid=34040260 |bibcode=2021Natur.594..223S |s2cid=235217720 |issn=0028-0836|url-access=subscription }}</ref>

== Nomenclature == Corystospermaceae is a family name which was not derived from a specific genus, an arrangement which is discouraged by the ICN.<ref>{{Cite journal |last=Doweld |first=Alexander B. |date=2017 |title=(2560) Proposal to conserve the name Umkomasiaceae against Zuberiaceae (fossil Peltaspermophyta: Umkomasiales ) |journal=Taxon |volume=66 |issue=5 |pages=1231–1232 |doi=10.12705/665.27 |issn=0040-0262|doi-access=free }}</ref> In light of this issue, Petriella (1981) proposed two solutions: either retain Corystospermaceae as a nomen conservandum, or replace it with a new name, Umkomasiaceae.<ref name=":5">{{Cite journal |last=Petriella |first=Bruno |date=1981 |title=Sistemática y vinculaciones de las Corystospermaceae H. Thomas |url=https://ameghiniana.org.ar/index.php/ameghiniana/article/view/1683 |journal=Ameghiniana |language=es |volume=18 |issue=3–4 |pages=221–234 |issn=1851-8044}}</ref> Both names have been used frequently since then. Petriella additionally named a new order to encompass the family, Corystospermales.<ref name=":5" /> Doweld (2001) preferred a different name for the order, Umkomasiales. He also added a second family, Angaropeltidaceae (previously known as Cardiolepidaceae).<ref name=":4" /> Later sources generally classify Angaropeltidaceae (or its updated spelling, Angaropeltaceae)<ref>{{Cite journal |last=Naugolnykh |first=Serge V. |date=2012 |title=Vetlugospermum and Vetlugospermaceae: A new genus and family of peltasperms from the Lower Triassic of Moscow syneclise (Russia) |url=https://www.researchgate.net/publication/258514671 |journal=Geobios |volume=45 |issue=5 |pages=451–462 |doi=10.1016/j.geobios.2011.10.009|bibcode=2012Geobi..45..451N }}</ref> within Peltaspermales instead.<ref>{{Cite journal |last=Naugolnykh |first=S. V. |date=2008 |title=A new gymnosperm ''Sylvocarpus armatus'' gen. et sp. nov. from the Lower Permian of the Ural Mountains |url=https://www.researchgate.net/publication/225379002 |journal=Paleontological Journal |volume=42 |issue=4 |pages=431–439 |doi=10.1134/s0031030108040138 |bibcode=2008PalJ...42..431N |s2cid=89345920 |issn=0031-0301}}</ref><ref>{{Cite journal |last1=Khramov |first1=Alexander V. |last2=Naugolnykh |first2=Sergey V. |last3=Węgierek |first3=Piotr |date=2022-09-12 |title=Possible long-proboscid insect pollinators from the Early Permian of Russia |journal=Current Biology |volume=32 |issue=17 |pages=3815–3820.e2 |doi=10.1016/j.cub.2022.06.085 |pmid=35858616 |issn=0960-9822|doi-access=free }}</ref>

== Gallery == <gallery mode="packed" heights="200" caption="(All examples from the Late Triassic Molteno Formation of South Africa)"> File:Umkomasia macleani.jpg|''Umkomasia macleanii'' ovulate structure from Umkomaas File:Pteruchus africanus.jpg|''Pteruchus africanus'' pollen structure from Umkomaas File:Dicroidium odontopteroides.jpg|''Dicroidium odontopteroides'' leaf from Birds River </gallery>

==See also== * Evolution of plants

==References== {{Reflist}}

==External links== *{{cite web|url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=157186|title=Fossilworks: Lepidopteris|publisher=paleodb.org|access-date=2016-03-18}}

Category:Pteridospermatophyta Category:Permian plants Category:Triassic plants Category:Prehistoric plant families Category:Permian first appearances Category:Triassic extinctions