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Parahughmilleria
''Parahughmilleria'' (meaning "near ''Hughmilleria''"Meaning opara-at ''www.dictionary.com''. Retrieved 17 July 2018.) is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of ''Parahughmilleria'' have been discovered in deposits of the Devonian and Silurian age in the United States, Canada, Russia, Germany, Luxembourg and Great Britain, and have been referred to several different species. The first fossils of ''Parahughmilleria'', discovered in the Shawangunk Mountains in 1907, were initially assigned to ''Eurypterus''. It would not be until 54 years later when ''Parahughmilleria'' would be described. ''Parahughmilleria'' is classified in the family Adelophthalmidae, the only clade in the superfamily Adelophthalmoidea. This clade was characterised by their small size, their parabolic (approximately U-shaped) carapaces and the presence of epimera (lateral "extensions" of the segment) on the seventh segment, among others. Like its relatives, ''Parahughmilleri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parahughmilleria Size
''Parahughmilleria'' (meaning "near ''Hughmilleria''"Meaning opara-at ''www.dictionary.com''. Retrieved 17 July 2018.) is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of ''Parahughmilleria'' have been discovered in deposits of the Devonian and Silurian age in the United States, Canada, Russia, Germany, Luxembourg and Great Britain, and have been referred to several different species. The first fossils of ''Parahughmilleria'', discovered in the Shawangunk Mountains in 1907, were initially assigned to ''Eurypterus''. It would not be until 54 years later when ''Parahughmilleria'' would be described. ''Parahughmilleria'' is classified in the family Adelophthalmidae, the only clade in the superfamily Adelophthalmoidea. This clade was characterised by their small size, their parabolic (approximately U-shaped) carapaces and the presence of epimera (lateral "extensions" of the segment) on the seventh segment, among others. Like its relatives, ''Parahughmilleri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parahughmilleria Hefteri Restoration
''Parahughmilleria'' (meaning "near ''Hughmilleria''"Meaning opara-at ''www.dictionary.com''. Retrieved 17 July 2018.) is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of ''Parahughmilleria'' have been discovered in deposits of the Devonian and Silurian age in the United States, Canada, Russia, Germany, Luxembourg and Great Britain, and have been referred to several different species. The first fossils of ''Parahughmilleria'', discovered in the Shawangunk Mountains in 1907, were initially assigned to ''Eurypterus''. It would not be until 54 years later when ''Parahughmilleria'' would be described. ''Parahughmilleria'' is classified in the family Adelophthalmidae, the only clade in the superfamily Adelophthalmoidea. This clade was characterised by their small size, their parabolic (approximately U-shaped) carapaces and the presence of epimera (lateral "extensions" of the segment) on the seventh segment, among others. Like its relatives, ''Parahughmilleri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adelophthalmidae
Adelophthalmidae (the name deriving from the type genus ''Adelophthalmus'', meaning "no obvious eyes") is a family of eurypterids, an extinct group of aquatic arthropods. Adelophthalmidae is the only family classified as part of the superfamily Adelophthalmoidea, which in turn is classified within the infraorder Diploperculata in the suborder Eurypterina. Adelophthalmid eurypterids were small and swimming eurypterids that appeared in the Silurian period. With the earliest known members of the group, '' Nanahughmilleria prominens'' and '' Parahughmilleria maria'', being known from deposits of Early Silurian (possibly the Llandovery epoch) age and the last members, belonging to the long-lasting and widespread genus ''Adelophthalmus'', going extinct in the Early Permian, the Adelophthalmidae is the longest lasting single family of eurypterids. The survival of the group, and of swimming eurypterids (the suborder Eurypterina) beyond the Late Devonian is entirely due to the survival, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adelophthalmid
Adelophthalmidae (the name deriving from the type genus ''Adelophthalmus'', meaning "no obvious eyes") is a family of eurypterids, an extinct group of aquatic arthropods. Adelophthalmidae is the only family classified as part of the superfamily Adelophthalmoidea, which in turn is classified within the infraorder Diploperculata in the suborder Eurypterina. Adelophthalmid eurypterids were small and swimming eurypterids that appeared in the Silurian period. With the earliest known members of the group, '' Nanahughmilleria prominens'' and '' Parahughmilleria maria'', being known from deposits of Early Silurian (possibly the Llandovery epoch) age and the last members, belonging to the long-lasting and widespread genus ''Adelophthalmus'', going extinct in the Early Permian, the Adelophthalmidae is the longest lasting single family of eurypterids. The survival of the group, and of swimming eurypterids (the suborder Eurypterina) beyond the Late Devonian is entirely due to the survival, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adelophthalmoidea
Adelophthalmidae (the name deriving from the type genus ''Adelophthalmus'', meaning "no obvious eyes") is a family of eurypterids, an extinct group of aquatic arthropods. Adelophthalmidae is the only family classified as part of the superfamily Adelophthalmoidea, which in turn is classified within the infraorder Diploperculata in the suborder Eurypterina. Adelophthalmid eurypterids were small and swimming eurypterids that appeared in the Silurian period. With the earliest known members of the group, '' Nanahughmilleria prominens'' and '' Parahughmilleria maria'', being known from deposits of Early Silurian (possibly the Llandovery epoch) age and the last members, belonging to the long-lasting and widespread genus ''Adelophthalmus'', going extinct in the Cisuralian, Early Permian, the Adelophthalmidae is the longest lasting single family of eurypterids. The survival of the group, and of swimming eurypterids (the suborder Eurypterina) beyond the Late Devonian is entirely due to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adelophthalmus
''Adelophthalmus'' is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of ''Adelophthalmus'' have been discovered in deposits ranging in age from the Early Devonian to the Early Permian, which makes it the longest lived of all known eurypterid genera, with a total temporal range of over 120 million years. ''Adelopththalmus'' was the final genus of the Eurypterina suborder of eurypterids and consisted the only known genus of swimming eurypterids from the Middle Devonian until its extinction during the Permian, after which the few surviving eurypterids were all walking forms of the suborder Stylonurina. Fossils of ''Adelophthalmus'' have been described from four continents; North America, Europe, Asia and Australia, which indicates that ''Adelophthalmus'' might have had a nearly cosmopolitan (worldwide) distribution, one of few eurypterid genera to achieve one besides potentially ''Pterygotus''. The territorial expansion of ''Adelophthalmus'' had begun early, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
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] |
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] |
Operculum (animal)
An operculum is an anatomical feature, a stiff structure resembling a lid or a small door that opens and closes, and thus controls contact between the outside world and an internal part of an animal. Examples include: * An operculum (gastropod), a single lid that (in its most complete form) closes the aperture of the shell when the animal is retracted, and thus protects the internal soft parts of the animal that are not completely covered by the shell. The operculum lies on the top rear part of the foot. When the foot is retracted, the operculum is rotated 180° and closes the shell. * An operculum (fish), a flap that covers the gills in bony fishes and chimaeras. * The cover that rapidly opens a cnida of a cnidarian such as a jellyfish or a sea anemone. The lid may be a single hinged flap or three hinged flaps arranged like slices of pie. * In insects, the operculum is the name for one or more lids covering the tympanal cavity. A subgenital operculum is exhibited in phasmoidea an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlantic Geology
''Atlantic Geology'' is a peer-reviewed scientific journal covering the geology of Atlantic Canada and related areas. It is the only regional geology journal in Canada and publishes papers, notes and discussions on original research, and review papers. It was established in 1965 and since 1986 has been published by the Atlantic Geoscience Society with digital publishing assistance from the University of New Brunswick. The journal was one of the first all-digital publications in Canada.Barr, S (2014). The history of the Atlantic Geology journal: the first 50 years. Keynote talk at the Atlantic Geoscience Society annual colloquium, Wolfville, Nova Scotia, February 2014. History The journal was established in 1965 as ''Maritime Sediments'' and later renamed ''Maritime Sediments and Atlantic Geology'' before obtaining its current name. The founding editor-in-chief was Daniel Stanley (Dalhousie University). Subsequent editors have included Deryck Laming, Bernard Pelletier, George Pajari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tergite
A ''tergum'' (Latin for "the back"; plural ''terga'', associated adjective tergal) is the dorsal ('upper') portion of an arthropod segment other than the head. The anterior edge is called the 'base' and posterior edge is called the 'apex' or 'margin'. A given tergum may be divided into hardened plates or sclerites commonly referred to as tergites. In a thoracic segment, for example, the tergum may be divided into an anterior notum and a posterior scutellum. Lateral extensions of a tergite are known as paranota (Greek for "alongside the back") or ''carinae'' (Latin for "keel"), exemplified by the flat-backed millipedes of the order Polydesmida. Kinorhynchs have tergal and sternal plates too, though seemingly not homologous with those of arthropods. Tergo-tergal is a stridulatory mechanism in which fine spines of the abdominal tergites are rubbed together to produce sound. This process is known as abdominal telescoping. Examples File:Andrena spiraeana abdomen.jpg , Abdominal t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telson
The telson () is the posterior-most division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment of the arthropod body, or an additional division that is not a true segment on account of not arising in the embryo from teloblast areas as other segments. It never carries any appendages, but a forked "tail" called the caudal furca may be present. The shape and composition of the telson differs between arthropod groups. Crustaceans In lobsters, shrimp and other decapods, the telson, along with the uropods, forms the tail fan. This is used as a paddle in the caridoid escape reaction ("lobstering"), whereby an alarmed animal rapidly flexes its tail, causing it to dart backwards. Krill can reach speeds of over 60 cm per second by this means. The trigger time to optical stimulus is, in spite of the low temperatures, only 55 milliseconds. In the Isopoda and Tanaidacea (superorder Peracarida), the last abdominal b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
