View source for Pteridospermatophyta

{{pp|small=yes}}
{{Short description|Several distinct polyphyletic groups of extinct seed-bearing plants}}
{{Paraphyletic group
| auto = yes
| fossil_range = {{Fossil range | 376 |50}} Late [[Devonian]] – Early [[Eocene]]
| image = FossilFernLeavesPennsylvanianOhio.jpg
| image_caption = Fossil seed fern leaves of ''[[Neuropteris]]'' ([[Medullosales]]) from the Late [[Carboniferous]] of northeastern [[Ohio]].
| taxon = Pteridospermatophyta
| includes = * †[[Calamopityales]]
* †[[Callistophytales]]
* †[[Caytoniales]]
* †[[Gigantopteridales]]
* †[[Glossopteridales]]
* †[[Lyginopteridales]]
* †[[Medullosales]]
* †[[Peltaspermales]]
* †[[Corystospermales]] (also referred to as Umkomasiales)
* †[[Petriellales]]
| excludes_text = Excluded
| excludes = * Magnoliopsida ([[flowering plant]]s)
* [[Cycadales]] (cycads)
* [[Ginkgoales]] (ginkgos)
* [[Pinophyta]] (conifers)
*[[Gnetophyta]]
*†[[Bennettitales]]
*†[[Czekanowskiales]]
*†[[Cordaitales]]
| image2 = Lepidopteris life restoration.jpg
| image2_caption = Life restoration of ''[[Lepidopteris]]'' ([[Peltaspermales]])
| synonyms = Pteridospermatopsida
}}

'''Pteridospermatophyta''', also called "'''pteridosperms'''" or "'''seed ferns'''" are a [[polyphyletic]]<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 |language=en |volume=180 |issue=6 |pages=578–596 |doi=10.1086/703461 |issn=1058-5893}}</ref> grouping of extinct [[Spermatophyte|seed-producing plants]]. The earliest fossil evidence for plants of this type are the [[Lyginopteridales|lyginopterids]] of late [[Devonian]] age.<ref name="Rothwelletal989">{{cite journal |author1=Rothwell G. W. |author2=Scheckler S. E. |author3=Gillespie W. H. | year = 1989 | title = ''Elkinsia'' gen. nov., a Late Devonian gymnosperm with cupulate ovules | journal = Botanical Gazette | volume = 150 | issue = 2| pages = 170–189 | doi=10.1086/337763|s2cid=84303226 }}</ref> They flourished particularly during the [[Carboniferous]] and [[Permian]] periods.  Pteridosperms declined during the [[Mesozoic]] Era and had mostly disappeared by the end of the [[Cretaceous]] Period, though ''[[Komlopteris]]'' seem to have survived into [[Eocene]] times, based on fossil finds in [[Tasmania]].<ref name="McLoughlinetal2008">{{cite journal |author1=McLoughlin S. |author2=Carpenter R.J. |author3=Jordan G.J. |author4=Hill R.S. | year = 2008 | title = Seed ferns survived the end-Cretaceous mass extinction in Tasmania | url = http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-319| journal = American Journal of Botany | volume = 95 | issue = 4| pages = 465–471 | doi=10.3732/ajb.95.4.465 | pmid=21632371| doi-access = free }}</ref>

With regard to the enduring utility of this [[division (botany)|division]], many palaeobotanists still use the pteridosperm grouping in an informal sense to refer to the seed plants that are not [[angiosperm]]s, coniferoids ([[conifer]]s or [[cordaite]]s), [[Ginkgoaceae|ginkgophytes]] or [[cycad]]ophytes (cycads or [[Bennettitales|bennettite]]s). This is particularly useful for extinct seed plant groups whose systematic relationships remain speculative, as they can be classified as pteridosperms with no valid implications being made as to their systematic affinities. Also, from a purely curatorial perspective the term pteridosperms is a useful shorthand for describing the fern-like fronds that were probably produced by seed plants, which are commonly found in many Palaeozoic and Mesozoic fossil floras.

==History of classification==
[[File:Bulgo Sandstone biota.jpg|thumb|Life restoration of the seed fern ''[[Dicroidium]]'' ([[Corystospermales|Corystospermales/Umkomasiales]], top right), in an Early Triassic Australian landscape]]
The concept of pteridosperms goes back to the late 19th century when [[Palaeobotany|palaeobotanists]] came to realise that many Carboniferous fossils resembling fern fronds had anatomical features more reminiscent of the modern-day seed plants, the [[cycads]]. In 1899 the German palaeobotanist [[Henry Potonié]] coined the term "''Cycadofilices''" ("cycad-ferns") for such fossils, suggesting that they were a group of non-seed plants intermediate between the [[fern]]s and cycads.<ref name="Potonie1899">{{cite book |last=Potonié |first=H. |year=1899 |title=Lehrbuch der Pflanzenpaläontologie |lang=de |place=Berlin, DE}}</ref>  Shortly afterwards, the British palaeobotanists [[Francis Wall Oliver|Frank Oliver]] and [[Dukinfield Henry Scott]] (with the assistance of Oliver's student at the time, [[Marie Stopes]]) made the critical discovery that some of these fronds (genus ''[[Lyginopteris]]'') were associated with seeds (genus ''[[Lagenostoma]]'') that had identical and very distinctive glandular hairs, and concluded that both fronds and seeds belonged to the same plant.<ref name="OliverScott1904">{{cite journal |author1=Oliver, F.W. |author2=Scott, D.H. | year = 1904 | title = On the structure of the Palaeozoic seed ''Lagenostoma Lomaxi'', with a statement of the evidence upon which it is referred to ''Lyginodendron'' | journal = Philosophical Transactions of the Royal Society of London |series=Series&nbsp;B | volume = 197 | issue = 225–238| pages = 193–247 | doi=10.1098/rstb.1905.0008| doi-access = free }}</ref> Soon, additional evidence came to light suggesting that seeds were also attached to the Carboniferous fern-like fronds ''[[Callistophytaceae|Dicksonites]]'',<ref name="Grandeury1904">{{cite journal | author = Grand'Eury C | year = 1904 | title = Sur les graines Neuropteridées | journal = Comptes Rendus de l'Académie des Sciences de Paris | volume = 140 | pages = 782–786 }}</ref> ''[[Neuropteris]]''<ref name="Kidston1904">{{cite journal | author = Kidston R | year = 1904 | title = On the fructification of ''Neuropteris heterophylla'', Brongniart | journal = Philosophical Transactions of the Royal Society of London, Series B | volume = 197 | issue = 225–238| pages = 1–5 | doi=10.1098/rstb.1905.0001| doi-access =  }}</ref> and ''Aneimites''.<ref name="White1904">{{cite journal | author = White D | year = 1904 | title = The seeds of ''Aneimites'' | journal = Smithsonian Institution, Miscellaneous Collection | volume = 47 | pages = 322–331 }}</ref>  Initially it was still thought that they were "[[transitional fossil]]s" intermediate between the ferns and cycads, and especially in the English-speaking world they were referred to as "seed ferns" or "pteridosperms".  Today, despite being regarded by most palaeobotanists as only distantly related to ferns, these spurious names have nonetheless established themselves. Nowadays, four orders of Palaeozoic seed plants tend to be referred to as pteridosperms: [[Lyginopteridales]], [[Medullosales]], [[Callistophytales]] and [[Peltaspermales]], with "Mesozoic seed ferns" including the [[Petriellales]], [[Corystospermales]] and [[Caytoniales]].<ref>Taylor, Edith L., et al. “Mesozoic Seed Ferns: Old Paradigms, New Discoveries.” ''The Journal of the Torrey Botanical Society'', vol. 133, no. 1, 2006, pp. 62–82. ''JSTOR'', {{JSTOR|20063823}}. Accessed 24 Sept. 2023.</ref>

Their discovery attracted considerable attention at the time, as the pteridosperms were the first extinct group of vascular plants to be identified solely from the fossil record.  In the 19th century the Carboniferous Period was often referred to as the "Age of Ferns" but these discoveries during the first decade of the 20th century made it clear that the "Age of Pteridosperms" was perhaps a better description.

During the 20th century the concept of pteridosperms was expanded to include various Mesozoic groups of seed plants with fern-like fronds, such as the [[Corystospermaceae]].  Some palaeobotanists also included seed plant groups with entire leaves such as the [[Glossopteridales]] and [[Gigantopteridales]], which was stretching the concept.  In the context of modern phylogenetic models,<ref name="HiltonBateman2006">{{citation |author1=Hilton, J.  |author2=Bateman, R. M.  |name-list-style=amp |year=2006 |title=Pteridosperms are the backbone of seed-plant phylogeny |journal=Journal of the Torrey Botanical Society |volume=33 |pages=119–168 |doi=10.3159/1095-5674(2006)133[119:PATBOS]2.0.CO;2|s2cid=86395036 }}</ref> the groups often referred to as pteridosperms appear to be liberally spread across a range of clades, and many palaeobotanists today would regard pteridosperms as little more than a [[paraphyletic]] 'grade-group' with no common lineage.{{clarification needed|reason=A paraphyletic group is part of a common lineage, it just excludes some ancestral groups. Should it be polyphyletic here? |date=March 2023}} One of the few characters that may unify the group is that the [[ovule]]s were borne in a [[:wiktionary:cupule|cupule]], a group of enclosing branches, but this has not been confirmed for all "pteridosperm" groups.

It has been speculated that some seed fern groups may be close to the ancestry of [[flowering plants]] (angiosperms). A 2009 study concluded that "[[Phylogenetics|phylogenetic]] analysis techniques have surpassed the hard data needed to formulate meaningful phylogenetic hypotheses" regarding the relationships of "seed ferns" to living plant groups.<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 |language=en |volume=96 |issue=1 |pages=237–251 |doi=10.3732/ajb.0800202 |pmid=21628187 |issn=0002-9122}}</ref>

==Taxonomy==
{{Unreferenced section|date=June 2021}}
=== Major groups ===
* Order †[[Calamopityales]] <small>Němejc (1963)</small>
* Order †[[Corystospermales]] <small>Petriella (1981)</small> [= Umkomasiales <small>Doweld (2001)</small>]
* Order †[[Callistophytales]] <small>Rothwell (1981) emend. Anderson, Anderson & Cleal (2007)</small> [Poroxylales <small>Němejc (1968)</small>]
* Order †[[Petriellales]] <small>Taylor et al. (1994)</small>
* Order †[[Peltaspermales]] <small>Taylor (1981)</small> [Lepidopteridales <small>Němejc (1968)</small>]
* Order †[[Gigantopteridales]] <small>Li & Yao (1983)</small> [Gigantonomiales <small>Meyen (1987)</small>]
* Order †[[Pentoxylales]] <small>Pilger & Melchior (1954)</small>
*Order †[[Glossopteridales]] <small>Plumstead, 1956</small>
* Order †[[Caytoniales]] <small>Gothan (1932)</small>
* Order †[[Medullosales]] <small>Corsin (1960)</small>
* Order †[[Lyginopteridales]] <small>(Corsin (1960)) Havlena (1961)</small> [Lagenostomatales <small>Seward ex Long (1975)</small>; Lyginodendrales <small>Nemejc (1968)</small>; Sphenopteridales <small>Schimper 1869</small>]
** Family †[[Angaranthaceae]] <small>Naugolnykh (2012)</small>
** Family †[[Heterangiaceae]] <small>Němejc (1950) [[nomen nudum|nom. nud.]]</small>
** Family †[[Physostomataceae]] <small>Long (1975)</small>
** Family †[[Lyginopteridaceae]] <small>Potonie (1900) emend. Anderson, Anderson & Cleal (2007)</small> [Lagenostomataceae <small>Long (1975</small>; Pityaceae <small>Scott (1909)</small>; Lyginodendraceae <small>Scott (1909)</small>; Sphenopteridaceae <small>Gopp. (1842)</small>; Pseudopecopteridaceae <small>Lesquereux (1884)</small>; Megaloxylaceae <small>Scott (1909), nom. rej.</small>; Rhetinangiaceae <small>Scott (1923), nom. rej.</small>; Tetratmemaceae <small>Němejc (1968)</small>]
** Family †[[Moresnetiaceae]] <small>Němejc (1963) emend. Anderson, Anderson & Cleal (2007)</small> [Genomospermaceae Long (1975)<small>; Elkinsiaceae Rothwell, Scheckler & Gillespie (1989) ex Cleal</small>; Hydraspermaceae]

=== Other minor groups ===

* Class ''[[incertae sedis]]''
** Order ''incertae sedis''
*** Family ?†Nystroemiaceae <small>Wang & Pfefferkorn (2009)</small><ref>{{Cite journal |last1=Wang |first1=Jun |last2=Pfefferkorn |first2=Hermann W. |date=2010-01-22 |title=Nystroemiaceae, a new family of Permian gymnosperms from China with an unusual combination of features |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=277 |issue=1679 |pages=301–309 |doi=10.1098/rspb.2009.0913 |issn=0962-8452 |pmc=2842674 |pmid=19656793}}</ref>
**** †''[[Nystroemia]]'' <small>Halle (1927)</small>
***Family †[[Austrocalyxaceae]] <small>Vega & Archangelsky (2001)</small><ref>{{Cite journal |last1=Vega |first1=Juan Carlos |last2=Archangelsky |first2=Sergio |date=2001-04-25 |title=Austrocalyxaeae, a new pteridoserm family from Gondwana |url=https://www.schweizerbart.de/papers/palb/detail/257/72575 |journal=Palaeontographica Abteilung B |volume=257 |issue=1–6 |language=en |pages=1–16|doi=10.1127/palb/257/2001/1 |bibcode=2001PalAB.257....1V |s2cid=248282839 }}</ref>
****†''[[Austrocalyx]]'' 
****†''[[Polycalyx]]''
****†''[[Rinconadia]]'' 
****†''[[Jejenia]]'' 
****†''[[Fedekurtzia]]'' (Archangelsky) emend. Coturel et Césari, 2017
** Order ?†Alexiales <small>Anderson & Anderson (2003)<ref name="Anderson-2003">{{Cite journal |last1=Anderson |first1=John M. |last2=Anderson |first2=Heidi M. |date=2003 |title=Heyday of the gymnosperms: systematics and biodiversity of the Late Triassic Molteno fructifications. |url=https://archive.org/details/heydayofgymnospe15ande/mode/2up |journal=Strelitzia |volume=15 |pages=1–308}}</ref></small>
*** Family †Alexiaceae <small>Anderson & Anderson (2003)</small>
**** †''[[Alexia (genus)|Alexia]]'' <small>Anderson & Anderson (2003)</small>
** Order †Buteoxylonales
*** Family †Buteoxylonaceae <small>Barnard & Long (1973)</small><ref>{{Cite journal |last1=Barnard |first1=P. D. W. |last2=Long |first2=A. G. |date=1973 |title=4.—On the Structure of a Petrified Stem and some Associated Seeds from the Lower Carboniferous Rocks of East Lothian, Scotland |url=https://www.cambridge.org/core/product/identifier/S008045680001499X/type/journal_article |journal=Transactions of the Royal Society of Edinburgh |language=en |volume=69 |issue=4 |pages=91–108 |doi=10.1017/S008045680001499X |s2cid=129792299 |issn=0080-4568}}</ref>
**** †''[[Buteoxylon]]'' <small>Barnard & Long (1973)</small>
**** †''[[Triradioxylon]]'' <small>Barnard & Long (1975)</small><ref>{{Cite journal |last1=Barnard |first1=P. D. W. |last2=Long |first2=A. G. |date=1975 |title=10.—Triradioxylon—a New Genus of Lower Carboniferous Petrified Stems and Petioles together with a Review of the Classification of Early Pterophytina |url=https://www.cambridge.org/core/product/identifier/S0080456800015179/type/journal_article |journal=Transactions of the Royal Society of Edinburgh |language=en |volume=69 |issue=10 |pages=231–249 |doi=10.1017/S0080456800015179 |issn=0080-4568}}</ref>
** Order †[[Dicranophyllales]] <small>Meyen (1984) emend. Anderson, Anderson & Cleal (2007)</small>
*** Family †[[Dicranophyllaceae]] <small>Němejc (1959) ex Archangelsky & Cúneo (1990)</small>
*** Family †[[Trichopityaceae]] <small>Němejc (1968) [Florin emend.]</small>
*** †''[[Polyspermophyllum]]''? <small>Archangelsky and Cúneo (1990)</small> (possibly a [[Coniferophyta|coniferophyte]])
** Order †[[Erdtmanithecales]] <small>Friis and Pedersen (1996)</small>
** Order †[[Fredlindiales]] <small>Anderson & Anderson (2003)<ref name="Anderson-2003" /></small>
** Order †[[Hamshawviales]] <small>Anderson & Anderson (2003)<ref name="Anderson-2003" /></small>
** Order †Hlatimbiales <small>Anderson & Anderson (2003)<ref name="Anderson-2003" /></small>
*** Family †Hlatimbiaceae <small>Anderson & Anderson (2003)</small>
**** †''[[Hlatimbia]]'' <small>Anderson & Anderson (2003)</small>
**** †''[[Batiopteris]]'' <small>Anderson & Anderson (2003)</small>
** Order †[[Matatiellales]] <small>Anderson & Anderson (2003)<ref name="Anderson-2003" /></small>
** Order †[[Nilssoniales]] <small>Darrah (1960)</small> (possibly [[Cycad|cycadopsids]])
** Order †[[Phasmatocycadales]] <small>Doweld (2001)</small> [Taeniopteridales]
*** Family †[[Phasmatocycadaceae]] <small>Doweld (2001)</small> [Spermopteridaceae <small>Doweld (2001)</small>]
**** †''[[Lesleya]]'' <small>Lesquereux (1879-80)</small> (otherwise placed as incetae sedis regarding family and order)
* Class †Axelrodiopsida <small>Anderson & Anderson (2007)<ref>{{Cite journal |last1=Anderson |first1=John M. |last2=Anderson |first2=Heidi M. |last3=Cleal |first3=Chris J. |date=2007 |title=Brief history of the gymnosperms: classification, biodiversity, phytogeography and ecology |url=http://opus.sanbi.org/bitstream/20.500.12143/5611/1/Strelitzia_20_2007.pdf |journal=Strelitzia |volume=20 |pages=1–280}}</ref></small>
** Order †Axelrodiales <small>Anderson & Anderson (2007)</small>
*** Family †Axelrodiaceae <small>Anderson & Anderson (2007)</small>
**** †''[[Axelrodia (plant)|Axelrodia]]'' <small>Cornet (1986)</small>
**** †''[[Sanmiguelia]]'' <small>Brown (1956)</small>
**** †''[[Synangispadixis]]'' <small>Cornet (1986)</small>
*** Family †Zamiostrobacea <small>Anderson & Anderson (2007)</small>
**** †''[[Zamiostrobus]]'' <small>Endlicher (1836)</small>
*Incertae sedis to order and family:
**†''[[Gnetopsis]]'' <small>Renault et Zeiller (1884)</small>
**†''[[Pullaritheca]]'' <small>Rothwell and Wight (1989)</small>
**†''[[Kegelidium]]'' <small>Dolianiti (1954)</small>

==References==
{{Reflist}}

== External links ==
* [https://web.archive.org/web/20050610075505/http://taggart.glg.msu.edu/bot335/sfern.htm Seed fern paleontology]
* [https://www.uni-muenster.de/GeoPalaeontologie/Palaeo/Palbot/seite9.html Seed ferns]

{{Plant classification}}
{{Taxonbar|from=Q1130372}}

[[Category:Pteridospermatophyta| ]]
[[Category:Plant divisions]]
[[Category:Prehistoric plants]]
[[Category:Devonian plants]]
[[Category:Carboniferous plants]]
[[Category:Permian plants]]
[[Category:Triassic plants]]
[[Category:Jurassic plants]]
[[Category:Cretaceous plants]]
[[Category:Paleocene plants]]
[[Category:Eocene plants]]
[[Category:Devonian first appearances]]
[[Category:Eocene extinctions]]
[[Category:Paraphyletic groups]]