|
Leiosphaeridia
''Leiosphaeridia'' is an extinct genus of algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ... or acritarchs. The genus of undefined species were found in outcrop ''Morro do Papaléo'' in the town of Mariana Pimentel in Brazil, the geopark Paleorrota. The outcrop date Sakmarian in Permian. See also * Leiosphaerid References {{Taxonbar, from=Q6520099 Acritarch genera Permian life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leiosphaerid
Leiosphaeridia is a form-genus of acritarchs proposed by Eisenack in 1958. The grouping was refined to represent a more natural group by Jankauskas. Some leiosphaerid acritarchs have been recognised as vaucheriacean algæ. The class represents shallow-water environments. See also * ''Leiosphaeridia ''Leiosphaeridia'' is an extinct genus of algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct cla ...'' References Acritarchs {{paleo-biota-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acritarchs
Acritarchs are organic microfossils, known from approximately 1800 million years ago to the present. The classification is a catch all term used to refer to any organic microfossils that cannot be assigned to other groups. Their diversity reflects major ecological events such as the appearance of predation and the Cambrian explosion. Definition Acritarchs were originally defined as non- acid soluble (i.e. non-carbonate, non-siliceous) organic-walled microfossils consisting of a central cavity, and whose biological affinities cannot be determined with certainty. Most commonly they are composed of thermally altered acid insoluble carbon compounds (kerogen). Acritarchs may include the remains of a wide range of quite different kinds of organisms—ranging from the egg cases of small metazoans to resting cysts of many kinds of chlorophyta (green algae). It is likely that most acritarch species from the Paleozoic represent various stages of the life cycle of algae that were ancestr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acritarch Genera
Acritarchs are organic microfossils, known from approximately 1800 million years ago to the present. The classification is a catch all term used to refer to any organic microfossils that cannot be assigned to other groups. Their diversity reflects major ecological events such as the appearance of predation and the Cambrian explosion. Definition Acritarchs were originally defined as non-acid soluble (i.e. non-carbonate, non-siliceous) organic-walled microfossils consisting of a central cavity, and whose biological affinities cannot be determined with certainty. Most commonly they are composed of thermally altered acid insoluble carbon compounds (kerogen). Acritarchs may include the remains of a wide range of quite different kinds of organisms—ranging from the egg cases of small metazoans to resting cysts of many kinds of chlorophyta (green algae). It is likely that most acritarch species from the Paleozoic represent various stages of the life cycle of algae that were ancestral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryota
Eukaryotes () are organisms whose Cell (biology), cells have a cell nucleus, nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the Three-domain system, three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard (archaea), Asgard archaea. This implies that there are only Two-domain system, two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass (ecology), biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as Flagellated cell, flagellated phagotrophs. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incertae Sedis
' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty at specific taxonomic levels is indicated by ' (of uncertain family), ' (of uncertain suborder), ' (of uncertain order) and similar terms. Examples *The fossil plant '' Paradinandra suecica'' could not be assigned to any family, but was placed ''incertae sedis'' within the order Ericales when described in 2001. * The fossil ''Gluteus minimus'', described in 1975, could not be assigned to any known animal phylum. The genus is therefore ''incertae sedis'' within the kingdom Animalia. * While it was unclear to which order the New World vultures (family Cathartidae) should be assigned, they were placed in Aves ''incertae sedis''. It was later agreed to place them in a separate order, Cathartiformes. * Bocage's longbill, ''Motacilla bocagii' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), 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 taxonomy (biology), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as ''Chlorella,'' ''Prototheca'' and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to in length. Most are aquatic and autotrophic (they generate food internally) and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the ''Charophyta'', a division of green algae which includes, for example, ''Spirogyra'' and stoneworts. No definition of algae is generally accepted. One definition is that algae "have chlorophyll ''a'' as their primary photosynthetic pigment and lack a sterile covering of cells around thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outcrop
An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. Features Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial deposits are covered by soil and vegetation and cannot be seen or examined closely. However, in places where the overlying cover is removed through erosion or tectonic uplift, the rock may be exposed, or ''crop out''. Such exposure will happen most frequently in areas where erosion is rapid and exceeds the weathering rate such as on steep hillsides, mountain ridges and tops, river banks, and tectonically active areas. In Finland, glacial erosion during the last glacial maximum (ca. 11000 BC), followed by scouring by sea waves, followed by isostatic uplift has produced many smooth coastal and littoral outcrops. Bedrock and superficial deposits may also be exposed at the Earth's surface due to human excavations such as quarrying and build ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mariana Pimentel
Mariana Pimentel is a municipality in the state of Rio Grande do Sul, Brazil. It is located approximately 75 km from the state's capital, Porto Alegre. Geography Mariana Pimentel belongs to Porto Alegre Metropolitan Mesoregion and to Porto Alegre Microregion. The municipality can be accessed through RS-711, which is connected to BR-116. Ecosystem The outcrop ''Morro do Papaléo'' within Mariana Pimentel was the discovery site of two species of the extinct algae '' Brazilea'', dating back to the Sakmarian of the Permian. See also *List of municipalities in Rio Grande do Sul This is a list of the municipalities in the state of Rio Grande do Sul (RS), located in the South Region of Brazil. Rio Grande do Sul is divided into 497 municipalities, which are grouped into 35 microregions, which are grouped into 7 mesoregio ... References External links Prefecture's website [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sakmarian
In the geologic timescale, the Sakmarian is an age or stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Sakmarian lasted between 293.52 and million years ago (Ma). It was preceded by the Asselian and followed by the Artinskian.; 2004: ''A Geologic Time Scale 2004'', Cambridge University Press Stratigraphy The Sakmarian Stage is named after the Sakmara River in the Ural Mountains, a tributary to the Ural River. The stage was introduced into scientific literature by Alexander Karpinsky in 1874. In Russian stratigraphy, it originally formed a substage of the Artinskian Stage. Currently, the ICS uses it as an independent stage in its international geologic timescale. The base of the Sakmarian Stage is laid with the first appearance of conodont species ''Streptognathodus postfusus'' in the fossil record. A global reference profile for the base (a GSSP), located in the southern Ural Mountains, Russia, was ratified in 2018. The top of the Sakmarian (the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
