Equisetopsida: Perbedaan antara revisi

'''Equisetopsida''', atau '''Sphenopsida''' di kalangan [[paleobotani]], adalah salah satu [[Kelas (biologi)|kelas]] [[tumbuhan berpembuluh]] yang masih lestari hingga kini namun dengan temuan fosil berusia sampai ke kala [[Devon (periode)|Devon]]. Anggotanya yang banyak dikenal adalah [[paku ekor kuda]] (''Equisetum'')<ref>{{cite web | url = http://www.merriam-webster.com/cgi-bin/dictionary?book=Dictionary&va=horsetail | title = horsetail | work = Merriam-Webster Online Dictionary }}</ref><ref name="Allaby 1999">{{cite book|last= Allaby|first= Ailsa|author2=Michael Allaby|year= 1999|title= "Sphenopsida." A Dictionary of Earth Sciences |url= https://archive.org/details/dictionaryofeart00alla}}</ref><ref name=Judd>{{cite book|last1=Judd|first1=W.S.|last2=Campbell|first2=C.S.|last3=Kellogg|first3=E.A.|last4=Stevens|first4=P.F.|last5=Donoghue|first5=M.J.|year=2002|title=Plant systematics, a phylogenetic approach.|publisher=Sinauer Associates, Inc.|location=Sunderland, Massachusetts|isbn=0878934030|page=193 }}</ref>. Kebanyakan anggotanya menyukai tempat yang becek / berair, dengan daun yang sangat tereduksi sehingga fotosintesis dilakukan oleh batang, yang umumnya beruas dan berbentuk berkas-berkas kaku.

The horsetails and their fossil relatives have long been recognized as distinct from other seedless vascular plants.<ref name="Eames 1936">{{cite book | last=Eames | first=Arthur J. | year=1936 | title=Morphology of Vascular Plants (Lower Groups) | pages=110–115 | location=New York and London | publisher=McGraw-Hill Book Company }}</ref> Before the advent of modern [[Molecular phylogenetics|molecular studies]], the relationship of this group to other living and fossil plants was considered problematic.<ref name="Bold 1987">{{cite book | last= Bold | first= Harold C. |author2=C. J. Alexopoulos |author3=T. Delevoryas | year= 1987 | title= Morphology of Plants and Fungi | edition= 5th | pages= 371–387, 478, 506–514 | location= New York | publisher= Harper-Collins | isbn= 0-06-040839-1 }}</ref> Because of their unclear relationships, the rank botanists have assigned to the horsetails varies from [[Order (biology)|order]] to [[Division (botany)|division]]. When recognized as a separate division, the literature uses many possible names, including Arthrophyta,<ref name="Bold 1987" /> Sphenophyta,<ref name="Taylor 1993" /><ref name="Gifford and Foster">{{cite book | last=Gifford | first=Ernest M. |author2=Adriance S. Foster | year=1988 | title=Morphology and Evolution of Vascular Plants | edition=3rd | pages=175–207 | location=New York | publisher=W. H. Freeman and Company | isbn=0-7167-1946-0 }}</ref> or Equisetophyta. Other authors have regarded the same group as a class, either within a division consisting of the vascular plants or, more recently, within an expanded fern group. When ranked as a class, the group has been termed the Equisetopsida<ref name="Kenrick 1997">{{cite book | last= Kenrick | first= Paul |author2=Peter R. Crane |year=1997 | title= The Origin and Early Diversification of Land Plants: A Cladistic Study | url= https://archive.org/details/originearlydiver0000kenr | pages= 241–242[https://archive.org/details/originearlydiver0000kenr/page/241 241]–242 | place= Washington, D. C. | publisher= Smithsonian Institution Press | isbn= 1-56098-730-8 }}</ref> or Sphenopsida.<ref name="Stewart and Rothwell">{{cite book | last= Stewart | first= Wilson N. |author2=Gar W. Rothwell | year= 1993 | title= Paleobotany and the Evolution of Plants | edition= 2nd | location= Cambridge | publisher= [[Cambridge University Press]] | isbn= 0-521-38294-7 }}</ref>