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Tortilicaulis
''Tortilicaulis'' is a moss-like plant known from fossils recovered from southern Britain, spanning the Silurian-Devonian boundary (around ). Originally recovered from the Downtonian of the Welsh borderlands, ''Tortilicaulis'' has since been recovered in the famous Ludlow Lane locality. Whilst it is generally accepted that ''Tortilicaulis'' was moss-like, it has not yet been recovered in a sufficiently good state of preservation to allow the detailed study necessary to firmly assign it to a taxonomic group. Fossils consist of an elongate apical sporangium (spore-forming organ), which may be branched, with spiralled walls attached to an undivided stalk that is also twisted. Unusually for plants of its time, spores of ''Tortilicaulis'' were covered all over with small granules. The initial suspicions of its describer, Dianne Edwards, were that it was a bryophyte, and comparisons have been made with several groups. A potential association with the moss '' Takakia'' is supp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horneophytopsida
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 ). 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. The group has also been treated as the division Horneophyta. 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. 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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dianne Edwards
Professor Dianne Edwards CBE, FRS, FRSE, FLS, FLSW (born 1942) is a palaeobotanist, who studies the colonisation of land by plants, and early land plant interactions. Early life Edwards was born in Swansea, South Wales, and spent much of her time at her parents' bungalow on the Gower Peninsula. Career Edwards' work has centred on early plant fossils, the majority of which have been retrieved from the UK. Her interest in early plants was initiated after she studied plant fossils preserved in three dimensions in the mineral pyrite (fools' gold). Much of her later work has centred on the Rhynie chert and charcoalified fossils, large and microscopic, from the Welsh borderlands and South Wales. Edwards is a Distinguished Research Professor, and former Head of School within the School of Earth and Ocean Sciences, at Cardiff University. She is also a Fellow of the Royal Society, Fellow of the Royal Society of Edinburgh, an honorary Fellow at the University of Wales, Swansea, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moss
Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hornworts. Mosses typically form dense green clumps or mats, often in damp or shady locations. The individual plants are usually composed of simple leaves that are generally only one cell thick, attached to a stem that may be branched or unbranched and has only a limited role in conducting water and nutrients. Although some species have conducting tissues, these are generally poorly developed and structurally different from similar tissue found in vascular plants. Mosses do not have seeds and after fertilisation develop sporophytes with unbranched stalks topped with single capsules containing spores. They are typically tall, though some species are much larger. ''Dawsonia'', the tallest moss in the world, can grow to in height. There are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Plant Genera
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silurian Plants
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods (myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone during th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Devonian Plants
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Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early Branch, a stream in Missouri * Early County, Georgia Other uses * ''Early'' (Scritti Politti album), 2005 * ''Early'' (A Certain Ratio album), 2002 * Early (name) * Early effect, an effect in transistor physics * Early Records, a record label * the early part of the morning See also * Earley (other) Earley is a town in England. Earley may also refer to: * Earley (surname), a list of people with the surname Earley * Earley (given name), a variant of the given name Earlene * Earley Lake, a lake in Minnesota *Earley parser, an algorithm *Earley ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polysporangiophyte
Polysporangiophytes, also called polysporangiates or formally Polysporangiophyta, are plants in which the spore-bearing generation (sporophyte) has branching stems (axes) that bear sporangia. The name literally means 'many sporangia plant'. The clade includes all land plants (embryophytes) except for the bryophytes (liverworts, mosses and hornworts) whose sporophytes are normally unbranched, even if a few exceptional cases occur. While the definition is independent of the presence of vascular tissue, all living polysporangiophytes also have vascular tissue, i.e., are vascular plants or tracheophytes. Extinct polysporangiophytes are known that have no vascular tissue and so are not tracheophytes. Early polysporangiophytes History of discovery Paleobotanists distinguish between micro- and megafossils. Microfossils are primarily spores, either single or in groups. Megafossils are preserved parts of plants large enough to show structure, such as stem cross-sections or branching patte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class (biology)
In biological classification, class ( la, classis) is a taxonomic rank, as well as a taxonomic unit, a taxon, in that rank. It is a group of related taxonomic orders. Other well-known ranks in descending order of size are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order. History The class as a distinct rank of biological classification having its own distinctive name (and not just called a ''top-level genus'' ''(genus summum)'') was first introduced by the French botanist Joseph Pitton de Tournefort in his classification of plants that appeared in his ''Eléments de botanique'', 1694. Insofar as a general definition of a class is available, it has historically been conceived as embracing taxa that combine a distinct ''grade'' of organization—i.e. a 'level of complexity', measured in terms of how differentiated their organ systems are into distinct regions or sub-organs—with a distinct ''type'' of construction, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryophyte
The Bryophyta s.l. are a proposed taxonomic division containing three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. Bryophyta s.s. consists of the mosses only. They are characteristically limited in size and prefer moist habitats although they can survive in drier environments. The bryophytes consist of about 20,000 plant species. Bryophytes produce enclosed reproductive structures (gametangia and sporangia), but they do not produce flowers or seeds. They reproduce sexually by spores and asexually by fragmentation or the production of gemmae. Though bryophytes were considered a paraphyletic group in recent years, almost all of the most recent phylogenetic evidence supports the monophyly of this group, as originally classified by Wilhelm Schimper in 1879. The term ''bryophyte'' comes . Terminology The term "Bryophyta" was first suggested by Braun in 1864. G.M. Smith placed this group between Algae and Pteridophyta. Features The d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Takakia
''Takakia'' is a genus of two species of mosses known from western North America and central and eastern Asia. The genus is placed as a separate family, order and class among the mosses. It has had a history of uncertain placement, but the discovery of sporophytes clearly of the moss-type firmly supports placement with the mosses. Discovery ''Takakia'' was discovered in the Himalayas and described by William Mitten in 1861. It was originally described simply as a new liverwort species (''Lepidozia ceratophylla'')Renzaglia, K. S., K. D. McFarland, & D. K. Smith. 1997. Anatomy and ultrastructure of the sporophyte of ''Takakia ceratophylla'' (Bryophyta). ''American Journal of Botany'' 84(10): 1337–1350. within an existing genus, and it was thus long overlooked. The discovery of similar odd plants in the mid-20th century by Dr. Noriwo Takaki (1915–2006) in Japan sparked more interest. The many unusual features of these plants led to the establishment in 1958 of the speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes (the archaea and bacteria). By one definition, plants form the clade Viridiplantae (Latin name for "green plants") which is sister of the Glaucophyta, and consists of the green algae and Embryophyta (land plants). The latter includes the flowering plants, conifers and other gymnosperms, ferns and their allies, hornworts, liverworts, and mosses. Most plants are multicellular organisms. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria. Their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic or mycotrophic and have lost the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sporangium
A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cycle. Sporangia can produce spores by mitosis, but in nearly all land plants and many fungi, sporangia are the site of meiosis and produce genetically distinct haploid spores. Fungi In some phyla of fungi, the sporangium plays a role in asexual reproduction, and may play an indirect role in sexual reproduction. The sporangium forms on the sporangiophore and contains haploid nuclei and cytoplasm. Spores are formed in the sporangiophore by encasing each haploid nucleus and cytoplasm in a tough outer membrane. During asexual reproduction, these spores are dispersed via wind and germinate into haploid hyphae. Although sexual reproduction in fungi varies between phyla, for some fungi the sporangium plays an indirect role in sexual reprod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
