|
Charophyte
Charophyta () is a paraphyletic group of freshwater green algae, called charophytes (), sometimes treated as a division, yet also as a superdivision. The terrestrial plants, the Embryophyta emerged deep within Charophyta, possibly from terrestrial unicellular charophytes, with the class Zygnematophyceae as a sister group. With the Embryophyta now cladistically placed in the Charophyta, it is a synonym of Streptophyta. The sister group of the charophytes are the Chlorophyta. In some charophyte groups, such as the Zygnematophyceae or conjugating green algae, flagella are absent and sexual reproduction does not involve free-swimming flagellate sperm. Flagellate sperm, however, are found in stoneworts (Charales) and Coleochaetales, orders of parenchymatous charophytes that are the closest relatives of the land plants, where flagellate sperm are also present in all except the conifers and flowering plants. Fossil stoneworts of early Devonian age that are similar to those of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octochara
''Octochara'' is a genus of fossil charophyte (aquatic green alga) from the Famennian (Late Devonian). It is one of two genera of charophyte described from the Waterloo Farm lagerstätte in southern Africa. It and ''Hexachara'', from the same locality provide the oldest record of reconstruct able charophytes with in situ oogonia. ''Octochara'' is derived from a Greek word "octo", meaning eight, a reference to the octoradial symmetry, and "chara", referring to membership of the Charales. In ''Octochara'', a whorl of eight laterals are borne at each node. Each lateral is branched to produce four secondary branches and bears an oogonium. Two species of ''Octochara'' have been described, ''Octochara crassa'' and ''Octochara gracilis''. The two species differ in the size and the shape of their secondary branchlets and oogonia. The specific name of ''O. crassa'' is derived from Latin, "crassus", meaning fat or thick, a reference to the branchlets. This species has whorls up to 14& ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexachara
''Hexachara'' is a genus of fossil charophyte (aquatic green alga) that is likely to have formed meadows within sheltered oligohaline reaches of lakes. Etymology ''Hexachara'' is derived from Greek "hex", meaning six, a reference to the hexaradial symmetry; chara, referring to membership of the Charales. The specific name ''setacea'' is derived from Latin "seta", a bristle, that is a reference to the thin pointed branchlet. The specific name ''riniensis'' is derived from the isiXhosa word ''Rhini'', which is a traditional name for Grahamstown/Makhanda, Eastern Cape, Makhanda and the surrounding valley. Description The Whorl (botany), whorls of branches are arranged in a hexaradial symmetrical manner. In ''Hexachara'' each node produces a whorl of six laterals, and oogonia are produced on each lateral. The known species to date include ''Hexachara setacea'' and ''Hexachara riniensis'' that have been recovered from a carbonaceous shale near the top of the Late Devonian, Famennian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Algae
The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryophytes) have emerged deep within the charophytes as a sister of the Zygnematophyceae. Since the realization that the Embryophytes emerged within the green algae, some authors are starting to include them. The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid (spherical), and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae, many of which live most of their lives as single cells, while other species form coenobia (colonies), long filaments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptophyta
Streptophyta (), informally the streptophytes (, from the Greek ''strepto'' 'twisted', for the morphology of the sperm of some members), is a clade of plants. The composition of the clade varies considerably between authors, but the definition employed here includes land plants and all green algae except the Chlorophyta and the more basal Prasinodermophyta. Classifications The composition of Streptophyta and similar groups (Streptophytina, Charophyta) varies in each classification. Some authors include only the Charales and Embryophyta (e.g., Streptophyta, Streptophytina); others include more groups (e.g., Charophyta, Streptophyta, Streptobionta); some authors use this broader definition, but exclude the Embryophyta (e.g., Charophyta, Charophyceae, Streptophycophytes). The clade Streptophyta includes both unicellular and multicellular organisms. Streptophyta contains the freshwater charophyte green algae and all land plants that reproduce sexually by conjugation. ''Mesostigma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterloo Farm Lagerstätte
The Waterloo Farm lagerstätte is a Famennian lagerstätte in South Africa that constitutes the only known record of a near-polar Devonian coastal ecosystem. History and discovery The Waterloo Farm Lagerstätte is an approximately 360 million year old Famennian (latest Devonian) fossil-rich locality of the Witpoort Formation (Witteberg Group, Cape Supergroup) in Makhanda, Eastern Cape, Makhanda (former Grahamstown) within the Eastern Cape, Eastern Cape Province, South Africa. Before its discovery very little was known of life during the Famennian (see Late Devonian extinction) in what is now southern Africa. This is largely due to the fact that fossils in the Witpoort Formation generally occur in black anaerobically deposited metashale that rapidly degrades near surface and is therefore rarely seen in natural outcrop. As is the case with many other scientific discoveries, the discovery of Waterloo Farm was accidental. Uprisings against the apartheid system in South Africa had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryophyta
The embryophytes () are a clade of plants, also known as Embryophyta (Plantae ''sensu strictissimo'') () or land plants. They are the most familiar group of photoautotrophs that make up the vegetation on Earth's dry lands and wetlands. Embryophytes have a common ancestor with green algae, having emerged within the Phragmoplastophyta clade of freshwater charophyte green algae as a sister taxon of Charophyceae, Coleochaetophyceae and Zygnematophyceae. Embryophytes consist of the bryophytes and the polysporangiophytes. Living embryophytes include hornworts, liverworts, mosses, lycophytes, ferns, gymnosperms and angiosperms (flowering plants). Embryophytes have diplobiontic life cycles. The embryophytes are informally called "land plants" because they thrive primarily in terrestrial habitats (despite some members having evolved secondarily to live once again in semiaquatic/ aquatic habitats), while the related green algae are primarily aquatic. Embryophytes are complex mult ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorokybophyceae
''Chlorokybus'' is a multicellular (sarcinoid) genus of basal green algae or charophyte. It has been classified as the sole member of the family Chlorokybaceae, which is the sole member of the order Chlorokybales, in turn the sole member of the class Chlorokybophyceae. It grows on soil and rock surfaces, and is rare. Description ''Chlorokybus'' is a microalga forming sarcinoid, cubical packets of two to eight cells. Each cell contains a single chloroplast which contains a central pyrenoid surrounded by grains of starch, as well as another pyrenoid (called the pseudopyrenoid) near the edge of the chloroplast which lacks starch grains. Mature packets produce a layer of mucilage surrounding the cells. ''Chlorokybus'' reproduces asexually by forming autospores. The autospores can also differentiate into zoospores, which have two flagella A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynie Chert
The Rhynie chert is a Lower Devonian Sedimentary rock, sedimentary deposit exhibiting extraordinary fossil detail or completeness (a Lagerstätte). It is exposed near the village of Rhynie, Aberdeenshire, Scotland; a second unit, the Windyfield chert, is located some 700 m away. The Rhynie chert contains exceptionally preserved plant, fungus, lichen and animal material preserved in place by an overlying Volcanic rock, volcanic deposit. The bulk of the Devonian fossil bed consists of primitive plants (which had xylem, water-conducting cells and spores, sporangia, but no true leaf, leaves), along with arthropods, lichens, algae and fungi. This fossil bed is remarkable for two reasons. First, the age of the site (Pragian, Early Devonian, formed about ) places it at an early stage in the colonisation of land. Second, these cherts are famous for their exceptional state of ultrastructure, ultrastructural preservation, with individual cell walls easily visible in polished specimen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phragmoplastophyta
The Phragmoplastophyta (Lecointre & Guyader 2006) are a proposed sister clade of the Klebsormidiaceae in the Streptophyte/Charophyte clade. The Phragmoplastophyta consist of the Charophyceae and another unnamed clade which contains the Coleochaetophyceae, Zygnematophyceae, Mesotaeniaceae, and Embryophytes (land plants). It is an important step in the emergence of land plants within the green algae. It is equivalent to the ZCC clade/grade, cladistically granting the Embryophyta. The mitosis of Phragmoplastophyta takes place via a phragmoplast. Another synapomorphy In phylogenetics, an apomorphy (or derived trait) is a novel Phenotypic trait, character or character state that has evolution, evolved from its ancestral form (or Plesiomorphy and symplesiomorphy, plesiomorphy). A synapomorphy is an apomorphy sh ... of this clade is the synthesis of cellulose microfibrils by a complex of octameric cellulose synthetases. This complex crosses the plasma membrane and polymerizes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charales
Charales is an order of freshwater green algae in the division Charophyta, class Charophyceae, commonly known as stoneworts. Depending on the treatment of the genus '' Nitellopsis'', living (extant) species are placed into either one family ( Characeae) or two (Characeae and Feistiellaceae). Further families are used for fossil members of the order. Linnaeus established the genus '' Chara'' in 1753. Taxonomy The higher level classification of green algae was unsettled . AlgaeBase places Charales within the class Charophyceae and its circumscription of the division Charophyta. Families The number of families and their division into genera varies. , AlgaeBase accepts two families containing some extant species and four families containing only fossil species: * Characeae S.F.Gray * Feistiellaceae Schudack *† Aclistocharaceae X.G.Zhou (may be included in Characeae) *† Atopocharaceae R.E.Peck (may be included in Clavatoraceae) *† Clavatoraceae Pia *† Porocharaceae Gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coleochaetales
Coleochaetaceae is a family of algae. It is the only family in the Coleochaetales, an order of parenchymous charophyte algae, within the class Coleochaetophyceae. It includes some of the closest multicellular relatives of land plants. It contains the genus Coleochaete and questionably includes the fossil genus ''Parka A parka, like the related anorak, is a type of coat (clothing), coat with a hood (headgear), hood, that may be lining (sewing), lined with fur or fake fur. Parkas and anoraks are staples of Inuit clothing, traditionally made from Reindeer, cari ...''. References Charophyta Chlorophyta families {{green alga-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
