|
Ginkgophyta
Ginkgoopsida is a proposed class of gymnosperms defined by Sergei V. Meyen in 1984 to encompass Ginkgoales (which contains the living ''Ginkgo'') alongside a number of extinct seed plant groups, which he considered to be closely related based on similarities of morphology of pollen, seeds, cuticles, short shoots and leaves. The validity of this group as a whole has been considered questionable by other authors, who consider that it is unlikely to be monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co .... Other authors have used the class as a monotypic grouping, including only Ginkgoales. Some authors have used the clade Ginkgophyta to encompass both Ginkgoales and Czekanowskiales/Leptostrobales, which are suggested to be closely related groups. References {{Taxonbar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ginkgoales
Ginkgoales are a gymnosperm Order (biology), order containing only one Neontology, extant species: ''Ginkgo biloba'', the ginkgo tree. The order has a long fossil record extending back to the Early Permian around 300 million years ago from fossils found worldwide. The Order (biology), order was a common component of Permian and Triassic flora before the super dominance of Conifer, conifers. Evolution Ginkgophyta and Cycadophyta have a very ancient divergence dating to the early Carboniferous. The earliest representative of the group in the fossil record is probably ''Trichopitys'' from the Asselian (299-293 million years ago) of France. The earliest representatives of ''Ginkgo'', represented by reproductive organs similar to the living species, first appear in the Middle Jurassic, alongside other, related forms such as ''Yimaia'' and ''Karkenia'', which have differently arranged reproductive structures and seeds associated with ''Ginkgo''-like leaves. The diversity of Ginkgoal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Czekanowskiales
Czekanowskiales, also known as Leptostrobales, are an extinct group of seed plants. Members of the family are distinguished by persistent leaves borne on deciduous short shoots, subtended by scale-like leaves. The leaves are highly dissected (divided into partitions). They likely grew as trees and shrubs. The main ovulate structure of Czekanowskiales, '' Leptostrobus,'' consists of bivalved seed-bearing round capsule-like structures arranged along a long axis. The fossil record of Czekanowskiales is largely confined to the Northern Hemisphere, and they inhabited warm-temperate and temperate climates under humid conditions. The oldest possible records of the group are ovulate cones from the Late Permian of Italy, but the group is primarily known from the Late Triassic onwards, and were abundant during the Jurassic and Early Cretaceous. Only a handful of species are known from the Late Cretaceous, confined to the northern Russian Far East, corresponding to the decline of other seed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnosperm
The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetophyta, gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in ( and ), and literally means 'naked seeds'. The name is based on the unenclosed condition of their seeds (called ovules in their unfertilized state). The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (angiosperms), which are enclosed within an Ovary (botany), ovary. Gymnosperm seeds develop either on the surface of scales or Leaf, leaves, which are often modified to form Conifer cone, cones, or on their own as in Taxus, yew, ''Torreya'', and ''Ginkgo''. The life cycle of a gymnosperm involves alternation of generations, with a dominant diploid sporophyte phase, and a reduced haploid gam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ginkgo
''Ginkgo'' is a genus of non-flowering seed plants, assigned to the gymnosperms. The scientific name is also used as the English common name. The order to which the genus belongs, Ginkgoales, first appeared in the Permian, , and ''Ginkgo'' is now the relict taxon, only living genus within the order. The rate of evolution within the genus has been slow, and almost all its species had become extinct by the end of the Pliocene. The sole surviving species, ''Ginkgo biloba'', is Species distribution, found in the wild only in China, but is cultivated around the world. The relationships between ginkgos and other groups of plants are not fully resolved. Prehistory The ginkgo (''Ginkgo biloba'') is a living fossil, with fossils similar to the modern plant dating back to the Permian, 270 million years ago. The ancestor of the genus is estimated to have branched off from other gymnosperms about 325 million years ago, while the last common ancestor of today's only remaining spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peltaspermales
The Peltaspermales are an extinct order of seed plants, often considered "seed ferns". 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''. Along with these, two informal groups (the " Supaioids" DiMichele, William A., Chaney, Dan S., Lucas, Spencer G., Kerp, Hans, and Voigt, Sebastian. 2013 "Flora of the Lower Permian Abo Formation redbeds, western equatorial Pangea, New Mexico."''New Mexico Museum of Natural History and Science Bulletin'', 59 265–288. and the " Comioids"Chaney, Dan S., Mamay, Serguis H., DiMichele, William A., and Kerp, Hans. 2009. "''Auritifolia'' gen. nov., Probabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corystospermales
Corystosperms are a group of extinct seed plants (often referred to as "seed ferns") belonging to the family Corystospermaceae (also called Umkomasiaceae) assigned to the order Corystospermales or Umkomasiales. They were first described based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa. Corystosperms are typified by a group of plants that bore forked '' Dicroidium'' leaves, '' Umkomasia'' cupulate ovulate structures and '' Pteruchus'' pollen organs, which grew as trees that were widespread over Gondwana during the Middle and Late Triassic. Other fossil Mesozoic seed plants with similar leaf and/or reproductive structures have also sometimes been included within the "corystosperm" concept ''sensu lato'', such as the "doyleoids" from the Early Cretaceous of North America and Asia. A potential corystosperm ''sensu lato'', the leaf genus ''Komlopteris'', is known from the Eocene of Tasmania, around 53-50 million yea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caytoniales
The Caytoniales (Figs. 1-2) are an extinct order of seed plants known from fossils collected throughout the Mesozoic Era, around . They are regarded as seed ferns because they are seed-bearing plants with fern-like leaves. Although at one time considered angiosperms because of their berry-like cupules, that hypothesis was later disproven. Nevertheless, some authorities consider them likely ancestors or close relatives of angiosperms. The origin of angiosperms remains unclear, and they cannot be linked with any known seed plants groups with certainty. History The first fossils identified in this order were discovered in the Middle Jurassic Gristhorpe bed of the Cloughton Formation in Cayton Bay, Yorkshire, with the name of the bay giving the name to the group. They have since been found in Mesozoic rocks all over world. It is likely that Caytoniales flourished in wetland areas, because they are often found with other moisture-loving plants such as horsetails in waterlogged paleo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calamopityales
Calamopityaceae is the largest family of the division of extinct seed-bearing plants (spermatophytes) known as Pteridospermatophyta. It is the only family in the monotypic order Calamopityales. This family is characterized by its petioles and specific wood pattern, and it grew only in the Paleozoic era, specifically in North America and Europe. Three form genera within the family are diagnosed by their stem structure: '' Calamopitys'', '' Stenomyelon'', and '' Diichinia''. It was named by Solms-Laubach in 1896. Since then, its genera have been added to and grouped differently. Morphology Calamopityaceae is the largest family in Pteriodspermatophyta. This family is composed of gymnosperms, and because of their stem structure discovered through fossil rocks, they are considered to be in this division. However, nothing is known of their reproductive organs, but they are classified as seed plants based on their similarities to the Lyginopteridaceae and Medullasaceae families with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callistophytales
Callistophytales is an extinct order of spermatophytes (seed plants) which lived from the Pennsylvanian (Late Carboniferous) to Permian periods. They were mainly scrambling and lianescent (vine-like) plants found in the wetland "coal swamps" of Euramerica and Cathaysia. Like many other early spermatophytes, they could be described as " seed ferns", combining ovule-based reproduction with pinnate leaves superficially similar to modern ferns. Callistophytales in particular are characterized by their reproductive anatomy. The ovules are bilaterally symmetrical and non-cupulate, attaching to the underside of pinnules that were otherwise morphologically identical to the standard non-reproductive pinnules. The pollen-bearing organs are small compound structures formed from up to eight tapering sporangia fused at their base. They are also borne on the underside of unmodified pinnules. Callistophytalean pollen was saccate (bearing buoyant sacs). Callistophytales were reproductively more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossopteridales
Glossopteridales is an extinct order of seed plants, known from the Permian of Gondwana. They arose at the beginning of the Permian, and the majority or all members of the group became extinct at the end of the Permian (251.9 mya), during the Permian-Triassic extinction event. Possible Triassic records of the group have been recorded. The best known genus is '' Glossopteris,'' a leaf form genus. Other examples are '' Gangamopteris,'' '' Glossotheca,'' and '' Vertebraria''. Permian permineralised glossopterid reproduction organs found in the central Transantarctic Mountains suggest seeds had an adaxial attachment to the leaf-like mega-sporophyll. This indicate Glossopteridales can be classified as seed ferns and is important in determining the status of the group as either close relatives or ancestors of the angiosperms. Midrib-less forms were common in the Early Permian whereas midrib forms were more common in the Late Permian Late or LATE may refer to: Everyday usage * T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
