The Horneophytopsida, informally called horneophytes, are a class of extinct plants which consisted of branched stems without leaves, true roots or vascular tissue, found from the Late Silurian to the Early Devonian (around 430 to390 million years ago). They are the simplest known polysporangiophytes, i.e. plants with sporophytes bearing many spore-forming organs (sporangia) on branched stems. They were formerly classified among the rhyniophytes, but it was later found that some of the original members of the group had simple vascular tissue and others did not.[1] The group has also been treated as the division Horneophyta.[2]
Horneophyton corms found in the Rhynie chert; scale bar is 1 cm.
In 2004, Crane et al. published a cladogram for the polysporangiophytes in which the Horneophytopsida are shown as the sister group of all other polysporangiophytes.[3] One other former rhyniophyte, Aglaophyton, is also placed outside the tracheophyteclade, as it did not possess true vascular tissue (in particular did not have tracheids), although its conducting tissue is more complex than that of the Horneophytopsida.
Other sources place only Horneophyton in this group, treating Caia and Tortilicaulis as actual or possible rhyniophytes.[4]
Referencesedit
^ abcKenrick, Paul & Crane, Peter R. (1997), The Origin and Early Diversification of Land Plants: a Cladistic Study, Washington, D.C.: Smithsonian Institution Press, ISBN978-1-56098-730-7
^Novíkov & Barabaš-Krasni (2015), Modern plant systematics, Liga-Pres, p. 685, doi:10.13140/RG.2.1.4745.6164, ISBN978-966-397-276-3
^ abcCrane, P.R.; Herendeen, P. & Friis, E.M. (2004), "Fossils and plant phylogeny", American Journal of Botany, 91 (10): 1683–99, doi:10.3732/ajb.91.10.1683, PMID 21652317
^Hao, Shougang & Xue, Jinzhuang (2013), The early Devonian Posongchong flora of Yunnan: a contribution to an understanding of the evolution and early diversification of vascular plants, Beijing: Science Press, p. 329, ISBN978-7-03-036616-0, retrieved 2019-10-25
horneophytopsida, informally, called, horneophytes, class, extinct, plants, which, consisted, branched, stems, without, leaves, true, roots, vascular, tissue, found, from, late, silurian, early, devonian, around, million, years, they, simplest, known, polyspor. The Horneophytopsida informally called horneophytes are a class of extinct plants which consisted of branched stems without leaves true roots or vascular tissue found from the Late Silurian to the Early Devonian around 430 to 390 million years ago They are the simplest known polysporangiophytes i e plants with sporophytes bearing many spore forming organs sporangia on branched stems They were formerly classified among the rhyniophytes but it was later found that some of the original members of the group had simple vascular tissue and others did not 1 The group has also been treated as the division Horneophyta 2 HorneophytopsidaTemporal range Late Silurian Early Devonian 1 PreꞒ Ꞓ O S D C P T J K Pg NReconstruction of Horneophyton lignieriScientific classificationKingdom PlantaeClade PolysporangiophytesClass HorneophytopsidaSynonymsLangiophytophyta Doweld 2001Horneophyton corms found in the Rhynie chert scale bar is 1 cm In 2004 Crane et al published a cladogram for the polysporangiophytes in which the Horneophytopsida are shown as the sister group of all other polysporangiophytes 3 One other former rhyniophyte Aglaophyton is also placed outside the tracheophyte clade as it did not possess true vascular tissue in particular did not have tracheids although its conducting tissue is more complex than that of the Horneophytopsida Contents 1 Phylogeny 2 Genera 3 References 4 External linksPhylogeny editPartial cladogram by Crane Herendeen amp Friis 2004 3 with emphasis on horneophytes polysporangiophytes Horneophytopsida TortilicaulisCaiaHorneophytonAglaophytonTracheophyta See the Polysporangiophyte article for the expanded cladogram Genera editGenera that have been placed in the horneophytes include 1 3 Caia Fanning Edwards amp Richardson 1990 Horneophyton Barghoorn amp Darrah 1938 Hornea Kidston amp Lang 1920 non Baker 1877 Langiophyton Remy amp Hass 1991 form taxon female gametophyte Tortilicaulis Edwards 1979 Other sources place only Horneophyton in this group treating Caia and Tortilicaulis as actual or possible rhyniophytes 4 References edit a b c Kenrick Paul amp Crane Peter R 1997 The Origin and Early Diversification of Land Plants a Cladistic Study Washington D C Smithsonian Institution Press ISBN 978 1 56098 730 7 Novikov amp Barabas Krasni 2015 Modern plant systematics Liga Pres p 685 doi 10 13140 RG 2 1 4745 6164 ISBN 978 966 397 276 3 a b c Crane P R Herendeen P amp Friis E M 2004 Fossils and plant phylogeny American Journal of Botany 91 10 1683 99 doi 10 3732 ajb 91 10 1683 PMID 21652317 Hao Shougang amp Xue Jinzhuang 2013 The early Devonian Posongchong flora of Yunnan a contribution to an understanding of the evolution and early diversification of vascular plants Beijing Science Press p 329 ISBN 978 7 03 036616 0 retrieved 2019 10 25External links editHorneophyton at the University of Aberdeen Cladogram from Crane Herendeen amp Friis 2004 Retrieved from https en wikipedia org w index php title Horneophytopsida amp oldid 1193404641, wikipedia, wiki, book, books, library,
