Gigantopterids (Gigantopteridales) is an extinct, possibly polyphyletic group of seed plants known from the Permian period. Gigantopterids were among the most advanced land plants of the Paleozoic Era and disappeared around the Permian–Triassic extinction event around 252 million years ago. Though some lineages of these plants managed to persist initially, they either disappeared entirely or adapted radically, evolving into undetermined descendants, as surviving life prospered again in much-altered ecosystems. One hypothesis[2] proposes that at least some "gigantopterids" became the ancestors of angiosperms and/or Bennettitales and/or Caytoniales.[3]
Gigantopterid fossils were documented as early as 1883, but only investigated more thoroughly in the early 20th century. Some of their most significant evidence was initially found in Texas, but they might have been present worldwide. Another key region for gigantopterid fossils is in China, and the consolidation of all major continents into Pangea would have allowed for easy global dispersal. They were among the most striking and important plants of the Cathaysian flora of Sino-Malaya, also called Gigantopteris flora to reflect this.[4]
They bore many of the traits of flowering plants, but are not known to have flowered themselves. Gigantopterid plants had simple, bilaterally symmetrical leaf structures, woody stems and spines. They grew new parts by producing shoots, like flowering plants. Judging from the fossil remains, they were probably robust plants with fronds that resembled fern fronds when young. When mature they were more like flowering plant leaves with reticulate venation arranged in a frond. Gigantopteris nicotianaefolia for example is named thus because each of its leaflets resembles a tobacco leaf in shape.
They grew at least over 20 cm (around 10 in), probably over 50 cm (20 in) tall, depending on whether it grew as a scrambling vine (the initial assumption) or erect (nowadays considered more likely). Some apparently preferred wetlands, while others throve in rather aridhabitats.[5]
The vascular tissue contains vessel elements and in at least some taxa resembles that of the Gnetophyta. They had a cuticle similar to that of other seed plants. Some male sporangia (Gigantotheca) and seeds (Gigantonomia, Cornucarpus) have been tentatively referred to this group.[6] While the sporangia are certainly not flowers, they differ from other sporangia of Permian plants.[4]
Chemical analysis of fossil remains indicates that gigantopterids produced oleananes, chemical compounds otherwise known to be used by flowering plants, for which they function as a suppressant of insect pests. They are apparently also found in certain modern ferns however[verification needed].[3]
Systematics
It is probable that the gigantopterids are a non-monophyleticform taxon.[7] Plant life from their era is very difficult to document and organize. They have been variously allied with the "seed ferns" (another paraphyletic group of early seed plants) Peltaspermales and Callistophytales, Gnetum, and the Magnoliophyta. All that can be said at present is that they were spermatophytes. It is also highly unlikely that they were close relatives of acrogymnosperms, cycads or ginkgos, because these lineages were already established and distinct in the Late Permian.[5]
Vegetative leaves of Emplectopteris were at one time included in this group. However, they had ovules attached to the underside of the fronds and are now placed in their own family (Emplectopteridaceae) within the Callistophytales.
Some prefer to refer to the presumed "core" taxa of this group as Gigantonomiales.[8] However, many experts remain skeptical of the new name, because they consider such a move premature until more is known about the interrelationships of the genera of "gigantopterids" and the relationships of these to other plants.[4]
Several genera have been named. Those then known were assigned to a familyGigantopteridaceae and numerous subfamilies by Gen-ichi Koidzumi.[9] It appears as if at least some of his divisions ought to prove useful when a more definite phylogenetic, systematic and taxonomic arrangement for this group is eventually found. On the other hand, the Gigantopteridaceae would with near certainty have to be more narrowly circumscribed even if the Gigantopteridales are by and large verified as a clade; they might even become limited to the two or so genera now placed in the Gigantopteridieae.[10]
Proposed subfamilies and genera
Cathaysiopteridieae - may be synonym of Palaeogoniopteridieae
Cathaysiopteris
Cathaysiopteridium
Gigantopteridieae (including Cardioglossieae)
Gigantonoclea - includes Cardioglossum and apparently[11]Progigantopteris[10]
Gigantopteris
Gothanopteridieae - may be synonym of Cathaysiopteridieae/Palaeogoniopteridieae
^Weiming Zhou; Mingli Wan; Rebecca A. Koll; Jun Wang (2018). "Occurrence of the earliest gigantopterid from the basal Permian of the North China Block and its bearing on evolution". Geological Journal. 53 (2): 500–509. doi:10.1002/gj.2907. S2CID 90421487.
^Ma, Fu-Jun; Sun, Bai-Nian; Liu, Song; Zhou, Guang-Hong; Ling, Chen-Chen; Hu, Xiao-Pan; Han, Dan; Wang, Qiu-Jun (May 2022). "A new gigantopterid taxon Paragigantopteris qingloongensis gen. et sp. nov. from the Permian (Wuchiapingian) of southwestern China: Taxonomic and biogeographic implications". Review of Palaeobotany and Palynology. 300: 104625. doi:10.1016/j.revpalbo.2022.104625. S2CID 246960147.
^Hongqi Li, B.S., M.S. (1996). . The Ohio State University. Archived from the original on 2018-07-26.{{cite web}}: CS1 maint: multiple names: authors list (link)
References
Asama, K. (1982): Evolution and phylogeny of vascular plants based on the principles of growth retardation: Part 5. Origin of angiosperms inferred from the evolution of leaf forms. Bulletin of the National Science Museum, Tokyo, Series C (Geology) 8: 43-58.
Glasspool, Ian; Hilton, Jason; Collinson, Margaret E. & Wang Shi-Jun (2004): Defining the gigantopterid concept: a reinvestigation of Gigantopteris (Megalopteris) nicotianaefolia Schenck and its taxonomic implications. Palaeontology47(6): 1339-1361. doi:10.1111/j.0031-0239.2004.00425.x (HTML abstract)
Koidzumi, Gen-ichi (1936): On the Gigantopteris flora. Acta Phytotaxonomica et Geobotanica5: 130–144.
Li Xingxue & Yao Zhao-Qi (1983): Fructifications of gigantopterids from South China. Palaeontographica Abteilung B185: 11-26.
Meyen, S.V. (1987): Fundamentals of palaeobotany. Chapman and Hall, London and New York.
Miller, John M. (2007): . Version of 2007-DEC-10. Retrieved 2007-DEC-12.
Wang Zi-Qiang (1999): Gigantonoclea: an enigmatic Permian plant from North China. Palaeontology42(2): 329–373. doi:10.1111/1475-4983.00076 (HTML abstract)
External links
Image from Li & Yao (1983), showing fossils and life reconstructions of Gigantonomia (denoted F) and Gigantotheca (denoted V). Retrieved 2007-DEC-12.
gigantopterid, ales, extinct, possibly, polyphyletic, group, seed, plants, known, from, permian, period, were, among, most, advanced, land, plants, paleozoic, disappeared, around, permian, triassic, extinction, event, around, million, years, though, some, line. Gigantopterids Gigantopteridales is an extinct possibly polyphyletic group of seed plants known from the Permian period Gigantopterids were among the most advanced land plants of the Paleozoic Era and disappeared around the Permian Triassic extinction event around 252 million years ago Though some lineages of these plants managed to persist initially they either disappeared entirely or adapted radically evolving into undetermined descendants as surviving life prospered again in much altered ecosystems One hypothesis 2 proposes that at least some gigantopterids became the ancestors of angiosperms and or Bennettitales and or Caytoniales 3 GigantopteridsTemporal range Asselian Late Permian PreꞒ Ꞓ O S D C P T J K Pg N 1 Scientific classificationKingdom PlantaeClade TracheophytesClade SpermatophytesDivision incertae sedisOrder GigantopteridalesGeneraSee text SynonymsGigantonomiales S MeyenGigantopterid fossils were documented as early as 1883 but only investigated more thoroughly in the early 20th century Some of their most significant evidence was initially found in Texas but they might have been present worldwide Another key region for gigantopterid fossils is in China and the consolidation of all major continents into Pangea would have allowed for easy global dispersal They were among the most striking and important plants of the Cathaysian flora of Sino Malaya also called Gigantopteris flora to reflect this 4 Contents 1 Description 2 Systematics 2 1 Proposed subfamilies and genera 3 See also 4 Footnotes 5 References 6 External linksDescription EditThey bore many of the traits of flowering plants but are not known to have flowered themselves Gigantopterid plants had simple bilaterally symmetrical leaf structures woody stems and spines They grew new parts by producing shoots like flowering plants Judging from the fossil remains they were probably robust plants with fronds that resembled fern fronds when young When mature they were more like flowering plant leaves with reticulate venation arranged in a frond Gigantopteris nicotianaefolia for example is named thus because each of its leaflets resembles a tobacco leaf in shape They grew at least over 20 cm around 10 in probably over 50 cm 20 in tall depending on whether it grew as a scrambling vine the initial assumption or erect nowadays considered more likely Some apparently preferred wetlands while others throve in rather arid habitats 5 The vascular tissue contains vessel elements and in at least some taxa resembles that of the Gnetophyta They had a cuticle similar to that of other seed plants Some male sporangia Gigantotheca and seeds Gigantonomia Cornucarpus have been tentatively referred to this group 6 While the sporangia are certainly not flowers they differ from other sporangia of Permian plants 4 Chemical analysis of fossil remains indicates that gigantopterids produced oleananes chemical compounds otherwise known to be used by flowering plants for which they function as a suppressant of insect pests They are apparently also found in certain modern ferns however verification needed 3 Systematics EditIt is probable that the gigantopterids are a non monophyletic form taxon 7 Plant life from their era is very difficult to document and organize They have been variously allied with the seed ferns another paraphyletic group of early seed plants Peltaspermales and Callistophytales Gnetum and the Magnoliophyta All that can be said at present is that they were spermatophytes It is also highly unlikely that they were close relatives of acrogymnosperms cycads or ginkgos because these lineages were already established and distinct in the Late Permian 5 Vegetative leaves of Emplectopteris were at one time included in this group However they had ovules attached to the underside of the fronds and are now placed in their own family Emplectopteridaceae within the Callistophytales Some prefer to refer to the presumed core taxa of this group as Gigantonomiales 8 However many experts remain skeptical of the new name because they consider such a move premature until more is known about the interrelationships of the genera of gigantopterids and the relationships of these to other plants 4 Several genera have been named Those then known were assigned to a family Gigantopteridaceae and numerous subfamilies by Gen ichi Koidzumi 9 It appears as if at least some of his divisions ought to prove useful when a more definite phylogenetic systematic and taxonomic arrangement for this group is eventually found On the other hand the Gigantopteridaceae would with near certainty have to be more narrowly circumscribed even if the Gigantopteridales are by and large verified as a clade they might even become limited to the two or so genera now placed in the Gigantopteridieae 10 Proposed subfamilies and genera Edit Cathaysiopteridieae may be synonym of Palaeogoniopteridieae Cathaysiopteris CathaysiopteridiumGigantopteridieae including Cardioglossieae Gigantonoclea includes Cardioglossum and apparently 11 Progigantopteris 10 GigantopterisGothanopteridieae may be synonym of Cathaysiopteridieae Palaeogoniopteridieae GothanopterisPalaeogoniopteridieae Gigantopteridium Palaeogoniopteris ZeilleropterisUnresolved Delnortea Emplectopteridium Emplectopteris Neogigantopteridium probably Cathaysiopteridieae Palaeogoniopteridieae VasovineaSee also EditOther Permian Triassic seed plants of unclear relationships are Glossopteridales Lyginopteridopsida PentoxyalesFootnotes Edit Weiming Zhou Mingli Wan Rebecca A Koll Jun Wang 2018 Occurrence of the earliest gigantopterid from the basal Permian of the North China Block and its bearing on evolution Geological Journal 53 2 500 509 doi 10 1002 gj 2907 S2CID 90421487 Asama 1982 a b Miller 2007 a b c Wang 1999 a b Wang 1999 Glasspool et al 2004 Li amp Yao 1983 Ma Fu Jun Sun Bai Nian Liu Song Zhou Guang Hong Ling Chen Chen Hu Xiao Pan Han Dan Wang Qiu Jun May 2022 A new gigantopterid taxon Paragigantopteris qingloongensis gen et sp nov from the Permian Wuchiapingian of southwestern China Taxonomic and biogeographic implications Review of Palaeobotany and Palynology 300 104625 doi 10 1016 j revpalbo 2022 104625 S2CID 246960147 Meyen 1987 Koidzumi 1936 a b Glasspool et al 2004 Hongqi Li B S M S 1996 PALEOBIOLOGY OF GIGANTOPTERIDS FROM THE UPPER PERMIAN OF GUIZHOU PROVINCE CHINA The Ohio State University Archived from the original on 2018 07 26 a href Template Cite web html title Template Cite web cite web a CS1 maint multiple names authors list link References EditAsama K 1982 Evolution and phylogeny of vascular plants based on the principles of growth retardation Part 5 Origin of angiosperms inferred from the evolution of leaf forms Bulletin of the National Science Museum Tokyo Series C Geology 8 43 58 Glasspool Ian Hilton Jason Collinson Margaret E amp Wang Shi Jun 2004 Defining the gigantopterid concept a reinvestigation of Gigantopteris Megalopteris nicotianaefolia Schenck and its taxonomic implications Palaeontology 47 6 1339 1361 doi 10 1111 j 0031 0239 2004 00425 x HTML abstract Koidzumi Gen ichi 1936 On the Gigantopteris flora Acta Phytotaxonomica et Geobotanica 5 130 144 Li Xingxue amp Yao Zhao Qi 1983 Fructifications of gigantopterids from South China Palaeontographica Abteilung B 185 11 26 Meyen S V 1987 Fundamentals of palaeobotany Chapman and Hall London and New York Miller John M 2007 Paleobotany of Angiosperm Origins Version of 2007 DEC 10 Retrieved 2007 DEC 12 Wang Zi Qiang 1999 Gigantonoclea an enigmatic Permian plant from North China Palaeontology 42 2 329 373 doi 10 1111 1475 4983 00076 HTML abstract External links EditImage from Li amp Yao 1983 showing fossils and life reconstructions of Gigantonomia denoted F and Gigantotheca denoted V Retrieved 2007 DEC 12 Photo of Delnortea abbottiae leaflet specimen USNM 387473 Retrieved 2007 DEC 12 Reconstruction of Gigantopteris leaves Retrieved 2007 DEC 12 Wikiadugi Version of this article permanent dead link in Cherokee language Retrieved 2007 DEC 12 Retrieved from https en wikipedia org w index php title Gigantopterid amp oldid 1146758623, wikipedia, wiki, book, books, library,
