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Brachyopterus
''Brachyopterus'' is a genus of prehistoric eurypterid of the family Rhenopteridae. It is one of the earliest known eurypterids, having been recovered from Middle Ordovician deposits in Montgomeryshire, Wales.Dunlop, J. A., Penney, D. & Jekel, D. 2015. A summary list of fossil spiders and their relatives. In World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch, version 16.0 http://www.wsc.nmbe.ch/resources/fossils/Fossils16.0.pdf (PDF). Though other species have been assigned to it in the past, ''Brachyopterus'' is today recognized as containing one valid species, ''B. stubblefieldi''. Description ''Brachyopterus'' is distinguished by its small size, compound eyes with axes converging anteriorly on a subtrapezoid to subpentagonal prosoma (head). All of its legs are walking legs; the first three pairs are short with spines, except when modified into clasping organs; the last two pairs are moderately long, keeled and tapering in width to terminal claws. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachyopterus Size
''Brachyopterus'' is a genus of prehistoric eurypterid of the family Rhenopteridae. It is one of the earliest known eurypterids, having been recovered from Middle Ordovician deposits in Montgomeryshire, Wales.Dunlop, J. A., Penney, D. & Jekel, D. 2015. A summary list of fossil spiders and their relatives. In World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch, version 16.0 http://www.wsc.nmbe.ch/resources/fossils/Fossils16.0.pdf (PDF). Though other species have been assigned to it in the past, ''Brachyopterus'' is today recognized as containing one valid species, ''B. stubblefieldi''. Description ''Brachyopterus'' is distinguished by its small size, compound eyes with axes converging anteriorly on a subtrapezoid to subpentagonal prosoma (head). All of its legs are walking legs; the first three pairs are short with spines, except when modified into clasping organs; the last two pairs are moderately long, keeled and tapering in width to terminal claws. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhenopteridae
The Rhenopteridae are a family of eurypterids, an extinct group of chelicerate arthropods commonly known as "sea scorpions". The family is the only family currently contained in the superfamily Rhenopteroidea, one of four superfamilies classified as part of the suborder Stylonurina. The family contains one of the earliest known eurypterids, '' Brachyopterus'', known from the Middle Ordovician (also the sister taxon to all other rhenopterids), and is the most primitive clade of stylonurine eurypterids. The last known members of the family went extinct during the Early Devonian. Description Rhenopterids were small, characterized by scattered tubercules and knobs on the outer surface of the exoskeleton. Their first two (or possibly three) pairs of walking legs had spines; the last two pairs were long and powerful, without spines. The prosoma (head) was subtrapezoidal, with arcuate compound eyes on parallel axes. The male genital appendages were short with two distal spines. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhenopteroidea
The Rhenopteridae are a family of eurypterids, an extinct group of chelicerate arthropods commonly known as "sea scorpions". The family is the only family currently contained in the superfamily Rhenopteroidea, one of four superfamilies classified as part of the suborder Stylonurina. The family contains one of the earliest known eurypterids, '' Brachyopterus'', known from the Middle Ordovician (also the sister taxon to all other rhenopterids), and is the most primitive clade of stylonurine eurypterids. The last known members of the family went extinct during the Early Devonian. Description Rhenopterids were small, characterized by scattered tubercules and knobs on the outer surface of the exoskeleton. Their first two (or possibly three) pairs of walking legs had spines; the last two pairs were long and powerful, without spines. The prosoma (head) was subtrapezoidal, with arcuate compound eyes on parallel axes. The male genital appendages were short with two distal spines. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylonurina
Stylonurina is one of two suborders of eurypterids, a group of extinct arthropods commonly known as "sea scorpions". Members of the suborder are collectively and informally known as "stylonurine eurypterids" or "stylonurines". They are known from deposits primarily in Europe and North America, but also in Siberia. Compared to the other suborder, Eurypterina, the stylonurines were comparatively rare and retained their posterior prosomal appendages for walking. Despite their rarity, the stylonurines have the longest temporal range of the two suborders. The suborder contains some of the oldest known eurypterids, such as ''Brachyopterus'', from the Middle Ordovician as well as the youngest known eurypterids, from the Late Permian. They remained rare throughout the Ordovician and Silurian, though the radiation of the mycteropoids (a group of large sweep-feeding forms) in the Late Devonian and Carboniferous is the last major radiation of the eurypterids before their extinction in the Pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Eurypterids
This list of eurypterid genera is a comprehensive listing of all genera that have ever been included in the order Eurypterida, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful ('' nomen dubium''), or were not formally published ('' nomen nudum''), as well as junior synonyms of more established names and genera that are no longer considered eurypterids. The list currently includes 115 names out of which 74 are considered valid eurypterid genera. There are approximately 250 species of eurypterids recognized as valid. Naming conventions and terminology There is no "official" or "canonical" list of eurypterid genera. The closest thing is found contained in the regularly updated ''Summary list'' ''of fossil spiders and their relatives'' in the World Spider Catalog. The vast majority of the content of the list below, including the valid genera, preoccupied names, junior synonyms, taxonomical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kiaeropterus
''Kiaeropterus'' is a genus of prehistoric eurypterid classified as part of the Rhenopteridae family. Two species, both from the Silurian period, are known; ''K. cyclophthalmus'' from Scotland and ''K. ruedemanni'' from Norway.Dunlop, J. A., Penney, D. & Jekel, D. 2015. A summary list of fossil spiders and their relatives. In World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch, version 16.0 http://www.wsc.nmbe.ch/resources/fossils/Fossils16.0.pdf (PDF). Description ''Kiaeropterus'' was a small eurypterid, with ''K. cyclophthalmus'' reaching lengths of about 6,6 cm. It had a subquadrate carapace with broad marginal rims. The eyes were large, covering about a third of the length of the carapace. The metasoma was narrow and the mesosoma not wider than the carapace, unlike in some eurypterids. The appendages V and VI were non-spiniferous and simple with individual podomeres having pronounced ridges. The genus is very poorly known. The type spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurypterids Of Europe
Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 million years ago. The group is likely to have appeared first either during the Early Ordovician or Late Cambrian period. With approximately 250 species, the Eurypterida is the most diverse Paleozoic chelicerate order. Following their appearance during the Ordovician, eurypterids became major components of marine faunas during the Silurian, from which the majority of eurypterid species have been described. The Silurian genus ''Eurypterus'' accounts for more than 90% of all known eurypterid specimens. Though the group continued to diversify during the subsequent Devonian period, the eurypterids were heavily affected by the Late Devonian extinction event. They declined in numbers and diversity until becoming extinct during the Permian–Triassic extinction event (or some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurypterid
Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the Order (biology), order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 Myr, million years ago. The group is likely to have appeared first either during the Early Ordovician or Late Cambrian period. With approximately 250 species, the Eurypterida is the most diverse Paleozoic Chelicerata, chelicerate order. Following their appearance during the Ordovician, eurypterids became major components of marine faunas during the Silurian, from which the majority of eurypterid species have been described. The Silurian genus ''Eurypterus'' accounts for more than 90% of all known eurypterid specimens. Though the group continued to diversify during the subsequent Devonian period, the eurypterids were heavily affected by the Late Devonian extinction event. They declined in numbers and diversity until becoming extinct during the Permian–Tri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhenopterus
''Rhenopterus'' is an extinct prehistoric eurypterid. Fossils of ''Rhenopterus'' have been recovered from deposits of Lower Devonian age in Germany.Dunlop, J. A., Penney, D. & Jekel, D. 2015. A summary list of fossil spiders and their relatives. In World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch, version 16.0 http://www.wsc.nmbe.ch/resources/fossils/Fossils16.0.pdf (PDF). Description Rhenopterids were small, characterized by scattered tubercules and knobs on the outer surface of the exoskeleton. Their first two (or possibly three) pairs of walking legs had spines; the last two pairs were long and powerful, without spines. The prosoma (head) was subtrapezoidal, with arcuate compound eyes on parallel axes. The male genital appendages were short with two distal spines. Species ''Rhenopterus'' contains three valid species, with other named species now seen as invalid or part of other genera. * ''Rhenopterus diensti'' Størmer, 1936 - Germany (Lower D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils Of Great Britain
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 absolu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Eurypterids
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic 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 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 beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed 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 Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian Perio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Ordovician
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic 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 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 beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed 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 Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian Pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
