Peltaspermales

Peltaspermales Temporal range: Late Carboniferous–Early Jurassic PreꞒ Ꞓ O S D C P T J K Pg N Some specimens From the Jurassic-Cretaceous boundary of Australia may belong to the Group
Life restoration of the Lepidopteris plant, with Lepidopteris ottonis foliage and Antevsia zeilleri pollen-producing microsporophylls, from the Late Triassic of Europe
Life restoration of Furcula granulifer from the Late Triassic of Greenland
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Spermatophytes
Order:	†Peltaspermales Delevoryas 1979[1]
Families and genera
See text

The Peltaspermales are an extinct order of seed plants, often considered "seed ferns".^[2] They span from the Late Carboniferous to the Early Jurassic or the Jurassic-Cretaceous Boundary. It includes at least one valid family, Peltaspermaceae, which spans from the Permian to Early Jurassic, which is typified by a group of plants with Lepidopteris leaves, Antevsia pollen-organs, and Peltaspermum ovulate organs, though the family now also includes other genera like Peltaspermopsis , Meyenopteris and Scytophyllum.^[3] Along with these, two informal groups (the "Supaioids"^[4][5] and the "Comioids"^[6]) of uncertain taxonomic affinities exist, each centered around a specific genus ; Supaia and Comia, known from the Early Permian of the Northern Hemisphere, especially of North America.^[4][6] Both the "Comioids" and the "Supaioids" are associated with the peltaspermacean ovulate organ Autunia (also known as Sandrewia).^[7][8] The Late Triassic-Middle Jurassic genus Pachydermophyllum may also have affinities to the peltasperms.^[3]

The morphology of peltasperm leaves is highly variable, ranging from dissected pinnate (fern-like) to forked and simple morphologies. The leaves of many peltasperms have "monocyclic stomata with wedge-shaped subsidiaries ending in a beak-like papilla overarching the guard cells", something which is found among other seed plant groups. The seed-bearing organs are generally fan-shaped or peltate.^[9]

It is unclear whether the broad grouping of peltasperms as a whole is monophyletic.^[2] Some authors have suggested that some peltasperms may have close affinities to corystosperms, another group of extinct seed plants.^[3] Meyen (1987) argued that Peltaspermales were ancestral to Ginkgoales, due to similarities between certain peltasperm form genera (Tatarina, Kirjamkenia, Stiphorus, Antevsia) and the extinct gingko Glossophyllum, and grouped peltasperms with Ginkgoales as part of Ginkgoopsida.^[10] Later authors have considered the position of Peltaspermales within seed plants to be uncertain.^[9]

It is suggested that at least some peltasperms may have been insect pollinated, with Pemian members of the long-probiscis scorpionfly family Protomeropidae from Russia associated with peltasperm pollen. The insects are suggested to have fed on pollination drops produced by peltasperm reproductive organs.^[11]

Evolutionary history

During the late Paleozoic, peltasperms are primarily known from the Northern Hemisphere,^[3] with Lepidopteris first appearing in the region during the Late Permian.^[12] During the Triassic, Lepidopteris became globally distributed and was abundant, especially during the Late Triassic. Lepidopteris populations collapsed during the end-Triassic mass extinction,^[3][13][14] with small populations persisting in Patagonia into the Early Jurassic.^[3] The genus Pachydermophyllum, along specimens referred as Lepidopteris? from the Battle Camp Formation of Clack Island, of latest Jurassic or earliest Cretaceous age may indicate an even longer survival in Gondwana.^[15]

Families, genera, and other groupings

• Family Peltaspermaceae
  • Lepidopteris (leaves)
  • Antevsia (pollen organs)
  • Peltaspermum (ovulate organ)
  • Peltaspermopsis (ovulate organ)
  • Meyenopteris (ovulate organ)
  • Kirjamkenia (leaves)
  • Scytophyllum (leaves)
  • Tatarina (leaves)
• "Supaioids"
  • Supaia (leaves)
  • Glenopteris (leaves)
  • Compsopteris (leaves)
  • Brongniartites (leaves)
• "Comioids"
  • Comia (leaves)
  • Auritifolia (leaves)
• Autunia (ovulate organ, formerly Sandrewia)
• Autuniopsis (ovulate organ)
• Lopadiangium (ovulate organ)
• Navipelta^[16] (ovulate organ)
• Permoxylocarpus (ovulate organ)
• Sporophyllites (ovulate organ)
• Stiphorus (ovulate organ)
• Tinsleya (ovulate organ)
• Pachydermophyllum? (leaves)
• Vittaephyllum (leaves)
• Taimyria (ovulate organ)^[17]
• Furcula (leaves)
• Matatiellaceae?^[18] (Other authors consider this family to be incertae sedis within seed plants^[19])
  • Dejerseya (leaves)
  • Matatiella (ovulate organ)

References

1. Peltaspermales et Fossilworks
2. Taylor, Edith L.; Taylor, Thomas N.; Krings, Michael (2009). Paleobotany: The Biology and Evolution of Fossil Plants. Academic Press. pp. 639–48. ISBN 9780080557830.
3. Elgorriaga, Andrés; Escapa, Ignacio H.; Cúneo, N. Rubén (July 2019). "Relictual Lepidopteris (Peltaspermales) from the Early Jurassic Cañadón Asfalto Formation, Patagonia, Argentina". International Journal of Plant Sciences. 180 (6): 578–596. doi:10.1086/703461. ISSN 1058-5893. S2CID 195435840.
4. "Flora of the Lower Permian abo Formation Redbeds, Western Equatorial Pangea, New Mexico".
5. Anderson, Heidi M.; Barbacka, Maria; Bamford, Marion K.; Holmes, W. B. Keith; Anderson, John M. (2020-01-02). "Dicroidium (foliage) and affiliated wood Part 3 of a reassessment of Gondwana Triassic plant genera and a reclassification of some previously attributed". Alcheringa: An Australasian Journal of Palaeontology. 44 (1): 64–92. Bibcode:2020Alch...44...64A. doi:10.1080/03115518.2019.1622779. ISSN 0311-5518. S2CID 199109037.
6. "Auritifolia gen. nov., Probable Seed Plant Foliage with Comioid Affinities from the Early Permian of Texas, U.S.A."
7. Krings, Michael; Klavins, Sharon D.; DiMichele, William A.; Kerp, Hans; Taylor, Thomas N. (October 2005). "Epidermal anatomy of Glenopteris splendens Sellards nov. emend., an enigmatic seed plant from the Lower Permian of Kansas (U.S.A.)". Review of Palaeobotany and Palynology. 136 (3–4): 159–180. Bibcode:2005RPaPa.136..159K. doi:10.1016/j.revpalbo.2005.07.002.
8. Mamay, Sergius H.; Chaney, Dan S.; DiMichele, William A. (February 2009). "Comia , a Seed Plant Possibly of Peltaspermous Affinity: A Brief Review of the Genus and Description of Two New Species from the Early Permian (Artinskian) of Texas, C. greggii sp. nov. and C. craddockii sp. nov". International Journal of Plant Sciences. 170 (2): 267–282. doi:10.1086/595294. ISSN 1058-5893. S2CID 85218041.
9. Coiro, Mario; McLoughlin, Stephen; Steinthorsdottir, Margret; Vajda, Vivi; Fabrikant, Dolev; Seyfullah, Leyla J. (2024-04-16). "Parallel evolution of angiosperm‐like venation in Peltaspermales: a reinvestigation of Furcula". New Phytologist. doi:10.1111/nph.19726. ISSN 0028-646X.
10. Meyen, Sergei V. (1987). "Evolution of Ginkgoopsida: from Peltaspermales to Ginkgoales, Leptostrobales and Caytoniales". Bulletin de la Société Botanique de France. Actualités Botaniques. 134 (2): 67–76. doi:10.1080/01811789.1987.10826864. ISSN 0181-1789.
11. Khramov, Alexander V.; Naugolnykh, Sergey V.; Węgierek, Piotr (September 2022). "Possible long-proboscid insect pollinators from the Early Permian of Russia". Current Biology. 32 (17): 3815–3820.e2. doi:10.1016/j.cub.2022.06.085. PMID 35858616. S2CID 250647525.
12. Zhang, Yi; Zheng, ShaoLin; Naugolnykh, Serge V. (September 2012). "A new species of Lepidopteris discovered from the Upper Permian of China with its stratigraphic and biologic implications". Chinese Science Bulletin. 57 (27): 3603–3609. Bibcode:2012ChSBu..57.3603Z. doi:10.1007/s11434-012-5282-0. ISSN 1001-6538. S2CID 130050063.
13. Slodownik, Miriam; Vajda, Vivi; Steinthorsdottir, Margret (February 2021). "Fossil seed fern Lepidopteris ottonis from Sweden records increasing CO2 concentration during the end-Triassic extinction event". Palaeogeography, Palaeoclimatology, Palaeoecology. 564: 110157. Bibcode:2021PPP...56410157S. doi:10.1016/j.palaeo.2020.110157. S2CID 230527791.
14. Vajda, Vivi; McLoughlin, Stephen; Slater, Sam M.; Gustafsson, Ola; Rasmusson, Allan G. (October 2023). "The 'seed-fern' Lepidopteris mass-produced the abnormal pollen Ricciisporites during the end-Triassic biotic crisis". Palaeogeography, Palaeoclimatology, Palaeoecology. 627: 111723. Bibcode:2023PPP...62711723V. doi:10.1016/j.palaeo.2023.111723. S2CID 260102119.
15. McLoughlin, Stephen; Martin, Sarah K.; Beattie, Robert (2015). "The record of Australian Jurassic plant–arthropod interactions". Gondwana Research. 27 (3): 940–959. doi:10.1016/j.gr.2013.11.009. ISSN 1342-937X.
16. Karasev, E. V. (2009). "A new genus Navipelta (Peltaspermales, Pteridospermae) from the Permian/Triassic boundary deposits of the Moscow syneclise" (PDF). Paleontological Journal. 43 (10): 1262–1271. doi:10.1134/S0031030109100086. ISSN 0031-0301.
17. Naugolnykh, Serge V.; Mogutcheva, Nina K. (2022). "Taimyria gen. nov., a new genus of evolutionary advanced gymnosperms from Triassic of the Taimyr Peninsula, Siberia, Russia". Fossil Imprint. 78 (2): 432–444. doi:10.37520/fi.2022.018. ISSN 2533-4069.
18. Bomfleur, Benjamin; Taylor, Edith L.; Taylor, Thomas N.; Serbet, Rudolph; Krings, Michael; Kerp, Hans (July 2011). "Systematics and Paleoecology of a New Peltaspermalean Seed Fern from the Triassic Polar Vegetation of Gondwana". International Journal of Plant Sciences. 172 (6): 807–835. doi:10.1086/660188. hdl:1808/13686. ISSN 1058-5893.
19. Pedernera, Tomás Ezequiel; Gómez, María Angélica (2022-02-22). "Plant reproductive structures of the Agua de la Zorra and Los Rastros formations, Triassic, Argentina". Revista Brasileira de Paleontologia. 24 (4): 336–344. doi:10.4072/rbp.2021.4.04. hdl:11336/171137.