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Eurypterus
''Eurypterus'' ( ) is an extinct genus of eurypterid, a group of organisms commonly called "sea scorpions". The genus lived during the Silurian period, from around 432 to 418 million years ago. ''Eurypterus'' is by far the most well-studied and well-known eurypterid. ''Eurypterus'' fossil specimens probably represent more than 95% of all known eurypterid specimens. There are fifteen species belonging to the genus ''Eurypterus'', the most common of which is ''E. remipes'', the first eurypterid fossil discovered and the state fossil of New York. Members of ''Eurypterus'' averaged at about in length, but the largest individual discovered was estimated to be long. They all possessed spine-bearing appendages and a large paddle they used for swimming. They were generalist species, equally likely to engage in predation or scavenging. Discovery The first fossil of ''Eurypterus'' was found in 1818 by S. L. Mitchill, a fossil collector. It was recovered from the Bertie Formation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurypterus
''Eurypterus'' ( ) is an extinct genus of eurypterid, a group of organisms commonly called "sea scorpions". The genus lived during the Silurian period, from around 432 to 418 million years ago. ''Eurypterus'' is by far the most well-studied and well-known eurypterid. ''Eurypterus'' fossil specimens probably represent more than 95% of all known eurypterid specimens. There are fifteen species belonging to the genus ''Eurypterus'', the most common of which is ''E. remipes'', the first eurypterid fossil discovered and the state fossil of New York. Members of ''Eurypterus'' averaged at about in length, but the largest individual discovered was estimated to be long. They all possessed spine-bearing appendages and a large paddle they used for swimming. They were generalist species, equally likely to engage in predation or scavenging. Discovery The first fossil of ''Eurypterus'' was found in 1818 by S. L. Mitchill, a fossil collector. It was recovered from the Bertie Formation of ... [...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] |
Bertie Formation
The Bertie Group or Bertie Limestone, also referred to as the Bertie Dolomite and the Bertie Formation, is an upper Silurian ( Pridoli, or Cayugan and Ulsterian age in the local chronologies) geologic group and Lagerstätte in southern Ontario, Canada, and western New York State, United States. Details of the type locality and of stratigraphic nomenclature for this unit as used by the U.S. Geological Survey are available on-line at the National Geologic Map Database. The formation comprises dolomites, limestones and shales and reaches a thickness of in the subsurface, while in outcrop the group can be thick. The group represents the uppermost unit of the Cayugan Series and the youngest Silurian unit in Ontario. The group overlies the Salina Group and is conformably overlain by the Devonian Bois Blanc Formation in Ontario and Onondaga Limestone in New York. Two formations within the Bertie Group, the Fiddler's Green and Williamsville, are considered Konservat-Lagerstät ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silurian
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods (myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Ellsworth De Kay
James Ellsworth De Kay (alternatively spelled DeKay or Dekay) (October 12, 1792 – November 21, 1851) was an American zoologist. Biography James De Kay was born in Lisbon, Portugal, in 1792. When he was two years old, his family moved to New York; both his parents died while he was still quite young. He attended Yale from 1807 to 1812, but was expelled before completing his degree when he threatened a college tutor with a club. Later, he studied medicine at the University of Edinburgh, receiving his MD in 1819. After his return to the United States, he married Janet Eckford, a daughter of Henry Eckford, a ship builder. He then traveled with his father-in-law to Turkey as a ship's physician, and published a book, ''Sketches of Turkey in 1831 and 1832,'' about these travels. Although well received as an entertaining travelogue, his book has been criticized as being very anti-Hellenic as well as sometimes naive about Turkish customs. He was entrusted by Eckford with negotiations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York (state)
New York, officially the State of New York, is a state in the Northeastern United States. It is often called New York State to distinguish it from its largest city, New York City. With a total area of , New York is the 27th-largest U.S. state by area. With 20.2 million people, it is the fourth-most-populous state in the United States as of 2021, with approximately 44% living in New York City, including 25% of the state's population within Brooklyn and Queens, and another 15% on the remainder of Long Island, the most populous island in the United States. The state is bordered by New Jersey and Pennsylvania to the south, and Connecticut, Massachusetts, and Vermont to the east; it has a maritime border with Rhode Island, east of Long Island, as well as an international border with the Canadian provinces of Quebec to the north and Ontario to the northwest. New York City (NYC) is the most populous city in the United States, and around two-thirds of the state's popul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiopoda
Branchiopoda is a class of crustaceans. It comprises fairy shrimp, clam shrimp, Diplostraca (or Cladocera), Notostraca and the Devonian ''Lepidocaris''. They are mostly small, freshwater animals that feed on plankton and detritus. Description Members of the Branchiopoda are unified by the presence of gills on many of the animals' appendages, including some of the mouthparts. This is also responsible for the name of the group (from the grc, βράγχια, gills, akin to , windpipe; el, πούς, foot). They generally possess compound eyes and a carapace, which may be a shell of two valves enclosing the trunk (as in most Cladocera), broad and shallow (as in the Notostraca), or entirely absent (as in the Anostraca). In the groups where the carapace prevents the use of the trunk limbs for swimming (Cladocera, clam shrimp and the extinct Lipostraca), the antennae are used for locomotion, as they are in the nauplius. Male fairy shrimp have an enlarged pair of antennae with which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. Some crustaceans (Remipedia, Cephalocarida, Branchiopoda) are more closely related to insects and the other hexapods than they are to certain other crustaceans. The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese spider crab with a leg span of up to and a mass of . Like other arthropods, crustaceans have an exoskeleton, which they moult to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates, by the possession of biramous (two-parted) limbs, and by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anostraca
Anostraca is one of the four orders of crustaceans in the class Branchiopoda; its members are referred to as fairy shrimp. They live in vernal pools and hypersaline lakes across the world, and they have even been found in deserts, ice-covered mountain lakes and Antarctic ice. They are usually long (exceptionally up to ). Most species have 20 body segments, bearing 11 pairs of leaf-like ''phyllopodia'' (swimming legs), and the body lacks a carapace. They swim "upside-down" and feed by filtering organic particles from the water or by scraping algae from surfaces. They are an important food for many birds and fish, and some are cultured and harvested for use as fish food. There are 300 species spread across 8 families. Description The body of a fairy shrimp is elongated and divided into segments. The whole animal is typically long, but one species, '' Branchinecta gigas'' does not reach sexual maturity until it reaches long, and can grow to long. The exoskeleton is thin and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Harlan
Richard Harlan (September 19, 1796 – September 30, 1843) was an American paleontologist, anatomist, and physician. He was the first American to devote significant time and attention to vertebrate paleontology and was one of the most important contributors to the field in the early nineteenth century. His work was noted for its focus on objective descriptions, taxonomy and nomenclature. He was the first American to apply Linnaean names to fossils. Biography Harlan was born in Philadelphia on September 19, 1796, to Joshua Harlan, a wealthy Quaker merchant, and his wife Sarah Hinchman Harlan, one of their ten children. He was three years older than his brother Josiah Harlan, who would become the first American to visit Afghanistan. Harlan graduated in medicine from the University of Pennsylvania in 1818 after taking time off during his studies to spend a year sailing to India as a ship's surgeon for the British East India Company. In 1821 he was elected professor of comparative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladocera
The Diplostraca or Cladocera, commonly known as water fleas, are a superorder of small crustaceans that feed on microscopic chunks of organic matter (excluding some predatory forms). Over 1000 species have been recognised so far, with many more undescribed. The oldest fossils of diplostracans date to the Jurassic, though their modern morphology suggests that they originated substantially earlier, during the Paleozoic. Some have also adapted to a life in the ocean, the only members of Branchiopoda to do so, even if several anostracans live in hypersaline lakes. Most are long, with a down-turned head with a single median compound eye, and a carapace covering the apparently unsegmented thorax and abdomen. Most species show cyclical parthenogenesis, where asexual reproduction is occasionally supplemented by sexual reproduction, which produces resting eggs that allow the species to survive harsh conditions and disperse to distant habitats. Description They are mostly long, with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silurus
''Silurus'' is a genus of catfishes native to Europe and Asia. Species There are currently 20 recognized species in this genus: * ''Silurus aristotelis'' Garman, 1890 (Aristotle's catfish) * ''Silurus asotus'' Linnaeus, 1758 (Amur catfish) * ''Silurus biwaensis'' Tomoda, 1961 (Lake Biwa giant catfish) * ''Silurus burmanensis'' Thant, 1967 * ''Silurus caobangensis'' V. H. Nguyễn, T. H. N. Vũ & T. D. P. Nguyễn, 2015 (Yellow catfish) * ''Silurus chantrei'' Sauvage, 1882 * ''Silurus dakrongensis'' V. H. Nguyễn, T. H. N. Vũ & T. D. P. Nguyễn, 2015 (Dakrong catfish) * ''Silurus duanensis'' X. Y. Hu, J. H. Lan & C. G. Zhang, 2004 * ''Silurus glanis'' Linnaeus, 1758 (Wels catfish) * ''Silurus grahami'' Regan, 1907 * ''Silurus langsonensis'' V. H. Nguyễn, T. H. N. Vũ & T. D. P. Nguyễn, 2015 (Flower catfish) * ''Silurus lanzhouensis'' H. L. Chen, 1977 (Lanzhou catfish) * ''Silurus lithophilus'' Tomoda, 1961 (Rock catfish) * ''Silurus longibarbatus'' Li, L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
