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Barinophyte
The barinophytes are a group of extinct vascular plants (tracheophytes). Their relationship with other vascular plants is unclear. They have been treated as the separate class Barinophytopsida, the order Barinophytales of uncertain class and as a family or clade Barinophytaceae within the zosterophylls. They have also been considered to be possible lycopodiopsids. Description ''Barinophyton'' is the type genus of the group; ''Protobarinophyton'' is similar. They were vascular plants with an exarch protostele. Plants consisted of alternatively arranged branches, apparently without leaves or enations, with their sporangia arranged in two rows on one-sided spike-like structures that developed on side shoots. Each sporangium was born on a curved bract-like appendage (a "sporangiferous appendage") and contained several thousand microspores, about 30–40 µm in diameter and about 30 megaspores, 410–560 µm in diameter, so that the plants were heterosporous. A similar pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zosterophyll
The zosterophylls are a group of extinct land plants that first appeared in the Silurian period. The taxon was first established by Banks in 1968 as the subdivision Zosterophyllophytina; they have since also been treated as the division Zosterophyllophyta or Zosterophyta and the class or plesion Zosterophyllopsida or Zosteropsida. They were among the first vascular plants in the fossil record, and had a world-wide distribution. They were probably stem-group lycophytes, forming a sister group to the ancestors of the living lycophytes. By the late Silurian (late Ludlovian, about ) a diverse assemblage of species existed, examples of which have been found fossilised in what is now Bathurst Island in Arctic Canada. Morphology The stems of zosterophylls were either smooth or covered with small spines known as enations, branched dichotomously, and grew at the ends by unrolling, a process known as circinate vernation. The stems had a central vascular column in which the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should clearly demons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Krithodeophyton
''Krithodeophyton'' is a genus of lower Devonian plant with branching axes. It is considered to be a barinophyte. Phylogeny The phylogenetic position of the barinophytes remains disputed. Kenrick and Crane in 1997 called the group the Barinophytaceae and placed it in their Sawdoniales, well nested within the zosterophylls. Taylor et al. in 2009 considered the barinophytes to be possible lycopsids rather than zosterophylls. Hao and Xue in 2013 suggested that they were not lycopsids, instead falling between this group and the euphyllophyte The euphyllophytes are a clade of plants within the tracheophytes (the vascular plants). The group may be treated as an unranked clade, a division Division or divider may refer to: Mathematics *Division (mathematics), the inverse of multipli ...s. References Early Devonian plants Prehistoric plant genera {{devonian-plant-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bracteophyton
''Bracteophyton'' is a genus of extinct vascular plants of the Early Devonian (around ) comprising a single species, ''Bracteophyton variatum''. Fossils were first found in the Xujiachong Formation of eastern Yunnan, China. The smooth stems (axes) mainly branched dichotomously. They bore terminal 'spikes' (strobili) consisting of spirally arranged fertile 'units'. Each unit was made up of one or two bracts and a spore-forming organ ( sporangium) between a bract and the stem. It appears that the sporangium released its spores by splitting along top. The arrangement of the sporangia resembles that of some zosterophylls, but the plant's discoverers considered its relationships uncertain. In 2013, Hao (one of the discoverers) and Xue listed the genus as a barinophyte The barinophytes are a group of extinct vascular plants (tracheophytes). Their relationship with other vascular plants is unclear. They have been treated as the separate class Barinophytopsida, the order Barinophyt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yunia
''Yunia'' is a genus of extinct vascular plants from the Early Devonian (Pragian or Siegenian stage, around ). It was first described from the Posongchong Formation of Yunnan, China. The leafless plant consisted of spiny stems, some 2 to 5 cm wide, which branched dichotomously at wide angles in a cruciate arrangement. Each stem contained vascular tissue with one or two strands of protoxylem. The spore-forming organs (sporangia) were elongated and borne on short stalks. The spores had a relatively smooth sculptural pattern and were trilete (i.e. each spore has three lines on it resulting from its formation in a tetrahedral set of four spores). In 2004, Crane et al. published a simplified cladogram for the polysporangiophytes in which ''Yunia'' is basal to the lycophytes The lycophytes, when broadly circumscribed, are a vascular plant (tracheophyte) subgroup of the kingdom Plantae. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Ly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euphyllophyte
The euphyllophytes are a clade of plants within the tracheophytes (the vascular plants). The group may be treated as an unranked clade, a division Division or divider may refer to: Mathematics *Division (mathematics), the inverse of multiplication *Division algorithm, a method for computing the result of mathematical division Military *Division (military), a formation typically consisting ... under the name Euphyllophyta or a subdivision under the name Euphyllophytina. The euphyllophytes are characterized by the possession of true leaves ("megaphylls"), and comprise one of two major lineages of extant vascular plants. As shown in the cladogram below, the euphyllophytes have a sister relationship to the lycopodiophytes or lycopsids. Unlike the lycopodiophytes, which consist of relatively few presently living or extant taxa, the euphyllophytes comprise the vast majority of vascular plant lineages that have evolved since both groups shared a common ancestor more than 400 mil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lycophyte
The lycophytes, when broadly circumscribed, are a vascular plant (tracheophyte) subgroup of the kingdom Plantae. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest lineages of extant (living) vascular plants; the group contains extinct plants that have been dated from the Silurian (ca. 425 million years ago). Lycophytes were some of the dominating plant species of the Carboniferous period, and included tree-like species, although extant lycophytes are relatively small plants. The scientific names and the informal English names used for this group of plants are ambiguous. For example, "Lycopodiophyta" and the shorter "Lycophyta" as well as the informal "lycophyte" may be used to include the extinct zosterophylls or to exclude them. Description Lycophytes reproduce by spores and have alternation of generations in which (like other vascular plants) the sporophyte generation is dominant. Some lycophyt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sawdoniales
The Sawdoniales are an order or plesion of extinct zosterophylls. The zosterophylls were among the first vascular plants in the fossil record, and share an ancestor with the living lycophytes. The group has been divided up in various ways. In their major cladistic study of early land plants, Kenrick and Crane placed most of the zosterophylls in the Sawdoniales (which they treated as a plesion). Like other zosterophylls, members of the Sawdoniales bore lateral, reniform sporangia. They branched dichotomously, and grew at the ends by unrolling (circinate vernation). Some had smooth stems, others were covered in small spines; fungal bodies have been reported in some spines. Taxonomy In 1997, Kenrick and Crane placed most of the zosterophylls in the plesion Sawdoniales, characterizing the group as having "marked bilateral symmetry". Their summary cladogram did not resolve the taxa within the Sawdoniales, other than placing '' Zosterophyllum divaricatum'' within the zosterophylls but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progymnosperm
The progymnosperms are an extinct group of woody, spore-bearing plants that is presumed to have evolved from the trimerophytes, and eventually gave rise to the gymnosperms, ancestral to acrogymnosperms and angiosperms (flowering plants). They have been treated formally at the rank of division Progymnospermophyta or class Progymnospermopsida (as opposite). The stratigraphically oldest known examples belong to the Middle Devonian order the Aneurophytales, with forms such as '' Protopteridium'', in which the vegetative organs consisted of relatively loose clusters of axes. ''Tetraxylopteris'' is another example of a genus lacking leaves. In more advanced aneurophytaleans such as ''Aneurophyton'' these vegetative organs started to look rather more like fronds, and eventually during Late Devonian times the aneurophytaleans are presumed to have given rise to the pteridosperm order, the Lyginopteridales. In Late Devonian times, another group of progymnosperms gave rise to the first r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeopteris
''Archaeopteris'' is an extinct genus of progymnosperm tree with fern-like leaves. A useful index fossil, this tree is found in strata dating from the Upper Devonian to Lower Carboniferous (), the oldest fossils being 385 million years old, and had global distribution. Until the 2007 discovery of ''Wattieza'', many scientists considered ''Archaeopteris'' to be the earliest known tree. Bearing buds, reinforced branch joints, and branched trunks similar to today's wood, it is more reminiscent of modern seed-bearing trees than other spore bearing taxa; It combines characteristics of woody trees and herbaceous ferns, and belongs to the progymnosperms, a group of extinct plants with gymnosperm-like wood but that produce spores rather than seeds. Taxonomy John William Dawson described the genus in 1871. The name derives from the ancient Greek (''archaīos'', "ancient"), and (''ptéris'', "fern"). ''Archaeopteris'' was originally classified as a fern, and it remained classif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascular Plant
Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). Scientific names for the group include Tracheophyta, Tracheobionta and Equisetopsida ''sensu lato''. Some early land plants (the rhyniophytes) had less developed vascular tissue; the term eutracheophyte has been used for all other vascular plants, including all living ones. Historically, vascular plants were known as "higher plants", as it was believed that they were further evolved than other plants due to being more complex organisms. However, this is an antiquated remnant of the obsolete scala naturae, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
