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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] |
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] |
Eurypterina
Eurypterina is one of two suborders of eurypterids, an extinct group of chelicerate arthropods commonly known as "sea scorpions". Eurypterine eurypterids are sometimes informally known as "swimming eurypterids". They are known from fossil deposits worldwide, though primarily in North America and Europe. Seventy-five percent of eurypterid species are eurypterines; this represents 99% of specimens. The superfamily Pterygotioidea is the most species-rich clade, with 56 species, followed by the Adelophthalmoidea with 43 species; as sister taxa, they comprise the most derived eurypterines. Pterygotioidea includes the pterygotids, which are the only eurypterids known to have a cosmopolitan distribution. Though more numerous both in specimens and taxa, the eurypterines have the shorter temporal range of the two eurypterid suborders. They first appeared around the same time as the Stylonurina in the Middle Ordovician. The suborder faced a slow extinction during the Middle and Late Devo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycteropoidea
Mycteropoidea is an extinct superfamily of eurypterids, an extinct group of chelicerate arthropods commonly known as "sea scorpions". It is one of four superfamilies classified as part of the suborder Stylonurina. Mycteropoids have been recovered from Europe, Russia, South America and South Africa. Mycteropoid specimens are often fragmentary, making it difficult to establish relationships between the included taxa. Only two mycteropoid taxa are known from reasonable complete remains, '' Hibbertopterus scouleri'' and ''H. wittebergensis''. Mycteropoids were large bizarre Eurypterids found from the Early Silurian to the end of the Permian period. They were sweep feeders, inhabiting freshwater swamps and rivers, feeding by raking through the soft sediment with blades on their anterior appendages to capture small invertebrates. Their morphology was so unusual that they have been thought to be an order separate to Eurypterida. Recent work however confirms them to be derived members o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycteropoid
Mycteropoidea is an extinct superfamily of eurypterids, an extinct group of chelicerate arthropods commonly known as "sea scorpions". It is one of four superfamilies classified as part of the suborder Stylonurina. Mycteropoids have been recovered from Europe, Russia, South America and South Africa. Mycteropoid specimens are often fragmentary, making it difficult to establish relationships between the included taxa. Only two mycteropoid taxa are known from reasonable complete remains, ''Hibbertopterus scouleri'' and ''H. wittebergensis''. Mycteropoids were large bizarre Eurypterids found from the Early Silurian to the end of the Permian period. They were sweep feeders, inhabiting freshwater swamps and rivers, feeding by raking through the soft sediment with blades on their anterior appendages to capture small invertebrates. Their morphology was so unusual that they have been thought to be an order separate to Eurypterida. Recent work however confirms them to be derived members of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hibbertopterus Scouleri
''Hibbertopterus'' is a genus of eurypterid, a group of extinct aquatic arthropods. Fossils of ''Hibbertopterus'' have been discovered in deposits ranging from the Devonian period in Belgium, Scotland and the United States to the Carboniferous period in Scotland, Ireland, the Czech Republic and South Africa. The type species, ''H. scouleri'', was first named as a species of the significantly different ''Eurypterus'' by Samuel Hibbert in 1836. The generic name ''Hibbertopterus'', coined more than a century later, combines his name and the Greek word πτερόν (''pteron'') meaning "wing". ''Hibbertopterus'' was the largest eurypterid within the stylonurine suborder, with the largest fossil specimens suggesting that ''H. scouleri'' could reach lengths around 180–200 centimetres (5.9–6.6 ft). Though this is significantly smaller than the largest eurypterid overall, ''Jaekelopterus'', which could reach lengths of around , ''Hibbertopterus'' is likely to have been the h ... [...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] |
Kokomopteroidea
Kokomopteroidea is an extinct superfamily of eurypterids, an extinct group of chelicerate arthropods commonly known as "sea scorpions". It is one of four superfamilies classified as part of the suborder Stylonurina. Kokomopteroids have been recovered from deposits of Early Silurian to Late Devonian age in the United States and the United Kingdom. Description Kokomopteroids are stylonurines with a spiniferous appendage V and a posterior notch on the metastoma. The superfamily forms two distinct clades; the Kokomopteridae (including the genera '' Kokomopterus'' and '' Lamontopterus'') and the Hardieopteridae (including the genera '' Hardieopterus'', '' Tarsopterella'' and '' Hallipterus''). The Kokomopteroidea retains primitive ''Hughmilleria''-type prosomal appendages for unsuitable raking through the bottom sediments of marine environments. As such, the members of the superfamily were likely scavengers. The Hardieopteridae display some sweep-feeding characteristics similarl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylonuroidea
Stylonuroidea is an extinct superfamily of eurypterids, an extinct group of chelicerate arthropods commonly known as "sea scorpions". It is one of four superfamilies classified as part of the suborder Stylonurina. Stylonuroidea, which lived from the Early Silurian to the Late Devonian, were characterized by their last pair of prosomal (head) appendages, which were developed as walking legs, or less commonly developed as swimming legs with paddles formed by the expansion of the two or three penultimate joints. 1955. Merostomata. ''Treatise on Invertebrate Paleontology, Part P Arthropoda 2, Chelicerata'', P36. as Stylonuracea Description Stylonuroids are designated as stylonurines with flattened or truncated posterior metastomata margins. Of the four stylonurine superfamilies, the Stylonuroidea is the most poorly known. Whilst the topology of most stylonurine clades fit well with the stratigraphic record, Stylonuroidea is an exception in that the earliest record of the most der ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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] |
Stylonurella
''Stylonurella'' is a genus of prehistoric eurypterid. It is classified within the Parastylonuridae family and contains three species, ''S. arnoldi'' and ''S. beecheri'' from the Devonian of Pennsylvania, United States and ''S. spinipes'' from the Silurian of Kip Burn, Scotland.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 ''Stylonurella'' was a small stylonuroid, possessing a subquadrate prosoma with approximately the same length as width. The midsection was slightly constricted and the eyes were parallel and anteriorly located in the anterior half of the carapace. The metastoma and first two appendages are unknown, the third and fourth prosomal legs are very short and the last two walking legs are very long. The metasoma is very narrow. A revision of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylonuroides
''Stylonuroides'' is a genus of prehistoric eurypterid. The genus is classified as a stylonurine but more precise classification has proven difficult, with the genus remaining classified as ''incertae sedis'' within the suborder. The genus contains two species, ''S. dolichopteroides'' from the Silurian of Ringerike, Norway and ''S. orientalis'' from the Devonian of Lake Shunet, Southern Siberia.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 The compound eyes of ''Stylonuroides'' are comparatively large, though their exact shape is unclear due to poor preservation. The posterior margin of the eyes lie in the middle of the prosoma. ''Stylonuroides orientalis'' is smaller in size than ''S. dolichopteroides'', with a prosoma measuring about 12 mm. ''S. o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
