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Mimetaster
''Mimetaster'' is an extinct genus of Marrellomorpha, marrellomorph arthropod. The type species, ''Mimetaster hexagonalis'' is known from the Lower Devonian (Pragian-Emsian) Hunsrück Slate, and amongst the most common arthropods from the locality, with over 120 specimens including three juveniles. Description The head shield of ''M. hexagonalis'' is oval shaped and raised on its upper surface, with three pairs of elongate straight projections radiating outwards, which have pairs of spines. On the upper surface was attached pair of probable eyes on segmented stalks. Attached on the underside was a pair of forward-projecting elongate segmented antennae, the first 10 segments of which were elongate, while the subsequent 14 were short and Flagellum, flagella-like, as well as two pairs of large uniramous leg-like appendages. The first of the two pairs was substantially larger than the second. Also present on the underside of the head was a Hypostome (trilobite), hypostome, as well as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mimetaster Diagram
''Mimetaster'' is an extinct genus of Marrellomorpha, marrellomorph arthropod. The type species, ''Mimetaster hexagonalis'' is known from the Lower Devonian (Pragian-Emsian) Hunsrück Slate, and amongst the most common arthropods from the locality, with over 120 specimens including three juveniles. Description The head shield of ''M. hexagonalis'' is oval shaped and raised on its upper surface, with three pairs of elongate straight projections radiating outwards, which have pairs of spines. On the upper surface was attached pair of probable eyes on segmented stalks. Attached on the underside was a pair of forward-projecting elongate segmented antennae, the first 10 segments of which were elongate, while the subsequent 14 were short and Flagellum, flagella-like, as well as two pairs of large uniramous leg-like appendages. The first of the two pairs was substantially larger than the second. Also present on the underside of the head was a Hypostome (trilobite), hypostome, as well as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomlinsonus
''Tomlinsonus'' is an extinct genus of marellomorph arthropod known from the Late Ordovician ( Katian) Kirkfield Formation of Ontario, Canada. It is a member of Marellida, and closely related to '' Mimetaster''. Description Only a single partial specimen (ROMIP 66233) was recovered during fieldwork in September 2020, by independent researcher Marc Haensel. This specimen preserves a mostly complete head and some appendages. Like other marellids, the head is composed of a cephalic shield with pairs of spine-like projections, with two large pairs present in ''Tomlinsonus''. These projections curve posteriorly. Like most other marellids, these projections are covered in second-order spines. There is also a pair of smaller projections without spines extending posteriorly from the back of the head. Attached to the head is a pair of extremely elongate appendages, around in length, with 9 podomeres, with a spine present on the end of the 8th podomere, which is the longest leg segm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marrellomorpha
Marrellomorpha are an extinct group of arthropods known from the Cambrian to the Early Devonian. They lacked mineralised hard parts, so are only known from areas of exceptional preservation, limiting their fossil distribution. The best known member is ''Marrella'', with thousands of specimens found in the Cambrian aged Burgess Shale of Canada. The group is divided up into two major orders, Marrellida and Acercostraca. Marrellida is recognised by the possession of head shields with two or three pairs of elongate spine-like projections, and three pairs of uniramous appendages on the cephalon, while Acercostraca generally have large ovoid carapaces that cover the entire upper half of the body, and five pairs of uniramous cephalic appendages. Both groups have unbranched antennules and a segmented trunk with biramous appendages. Recent research has suggested the previously enigmatic Cambrian trliobite-like arthropods ''Skania'' and ''Primicaris'' may belong to this group. Their phylo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furca (genus)
''Furca'' (Latin for "fork") is an extinct genus of marrellomorph arthropod known from the Sandbian stage (upper Ordovician period) of the Czech Republic, with a single currently described species, ''Furca bohemica''. A tentative additional species, "Furca mauretanica": was proposed for specimens discovered in Morocco, but this species remains a ''nomen nudum'' until formally published, and probably belongs in a new separate genus. Description ''Furca'' is characterized by a broad head shield with three pairs of prominent spines: front (anterolateral), side (mediolateral) and rear (posterolateral). The head shield of ''Furca'' ranged from long and at maximum width. The mediolateral spines are long and strongly curved. The outline of the head shield possess a fringe of small, gently curving secondary spines, between long. Appendages are unknown from fossils. Paleobiology ''Furca'' fossils have been found in sediments indicative of shallow marine habitats. Since appendages an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen(s). Article 67.1 A similar concept is used for suprageneric groups and called a type genus. In botanical nomenclature, these terms have no formal standing under the code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus name is a specimen (or, rarely, an illustration) which is also the type of a species name. The species name that has that type can also be referred to as the type of the genus name. Names of genus and family ranks, the various subdivisions of those ranks, and some higher-rank names based on genus names, have such types. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian Argentina
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hunsrück Slate Fossils
The Hunsrück () is a long, triangular, pronounced upland in Rhineland-Palatinate, Germany. It is bounded by the valleys of the Moselle-Saar (north-to-west), the Nahe (south), and the Rhine (east). It is continued by the Taunus mountains, past the Rhine and by the Eifel past the Moselle. To the south of the Nahe is a lower, hilly country forming the near bulk of the Palatinate region and all of the, smaller, Saarland. Below its north-east corner is Koblenz. As the Hunsrück proceeds east it acquires north-south width and three notable gaps in its southern ridges. In this zone are multi-branch headwaters including the Simmerbach ending at Simmertal on the southern edge. This interior is therefore rarely higher than above sea level. Peaks and escarpments are principally: the (Black Forest) Hochwald, the Idar Forest, the Soonwald, and the Bingen Forest. The highest mountain is the Erbeskopf (816 m; 2,677 ft), towards the region's south-west. Notable towns are Simmern, Ki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils Of Germany
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian Arthropods
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floresta Formation, Argentina
{{disambig, geo ...
Floresta may refer to: Geography * Floresta, Pernambuco, a city in the state of Pernambuco, Brazil * Floresta, Rio Grande do Sul, a neighbourhood in Porto Alegre, Brazil * Floresta, Boyacá, a municipality in Boyacá Department, Colombia * Floresta, Buenos Aires, a neighborhood in Buenos Aires, Argentina * Floresta, Sicily, a municipality in the province of Messina, Sicily * La Floresta, Uruguay, a small city located in Canelones Department, Uruguay * La Floresta, Guayaquil, a neighborhood located in Guayaquil, Ecuador Geology * Floresta Formation, a fossiliferous geological formation of the Altiplano Cundiboyacense, named after Floresta, Boyacá See also * La Floresta (other) La Floresta can refer to: * La Floresta, Quito, electoral parish in Quito, Ecuador * La Floresta, Córdoba, town in Capital Department, Córdoba Province, Argentina * La Floresta, Lleida, municipality in the province of Lleida, Catalonia, Spain * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tremadocian
The Tremadocian is the lowest stage of Ordovician. Together with the later Floian Stage it forms the Lower Ordovician Epoch. The Tremadocian lasted from to million years ago. The base of the Tremadocian is defined as the first appearance of the conodont species ''Iapetognathus fluctivagus'' at the Global Boundary Stratotype Section and Point (GSSP) section on Newfoundland. Naming The Tremadocian is named after the village Tremadoc in Wales. The name was proposed by Adam Sedgwick in 1846 (as "Tremadoc group"). GSSP The GSSP for the beginning of the Tremadocian is the Greenpoint section () in Gros Morne National Park, in western Newfoundland. It is defined as the first appearance of the conodont species ''Iapetognathus fluctivagus''. This horizon can be found 101.8 m above the Greenpoint section datum within bed number 23. The boundary lies within the Broom Point Member, of the Green Point Formation which is part of the Cow Head Group. The first planktonic graptolites appear 4.8 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Union of Geological Sciences, Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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