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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 List of U.S. state fossils, state fossil of New York (state), 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 and specialist species, generalist species, equally likely to engage in predation or scavenging. Discovery The first fossil of ''Eurypterus'' was found in 1818 by S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurypterid
Eurypterids, often informally called sea scorpions, are a group of extinct marine 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 Permi ... [...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 Silurian, upper Silurian (Pridoli epoch, Pridoli, or Cayugan) geologic Group (stratigraphy), 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 dolomite (rock), 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 Lagerstä ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silurian
The Silurian ( ) is a geologic period and system spanning 23.5 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 third and shortest period of the Paleozoic Era, and the third of twelve periods of the Phanerozoic Eon. 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) ... [...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 City, 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 Doctor of Medicine, MD in 1819. After his return to the United States, he married Janet Eckford, a daughter of Henry Eckford (shipbuilder), 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 (literature), travelogue, his book has been criticized as being very anti-Hellenic as we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York (state)
New York, also called New York State, is a U.S. state, state in the northeastern United States. Bordered by New England to the east, Canada to the north, and Pennsylvania and New Jersey to the south, its territory extends into both the Atlantic Ocean and the Great Lakes. New York is the List of U.S. states and territories by population, fourth-most populous state in the United States, with nearly 20 million residents, and the List of U.S. states and territories by area, 27th-largest state by area, with a total area of . New York has Geography of New York (state), a varied geography. The southeastern part of the state, known as Downstate New York, Downstate, encompasses New York City, the List of U.S. cities by population, most populous city in the United States; Long Island, with approximately 40% of the state's population, the nation's most populous island; and the cities, suburbs, and wealthy enclaves of the lower Hudson Valley. These areas are the center of the expansive New ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiopoda
Branchiopoda, from Ancient Greek βράγχια (''bránkhia''), meaning "gill", and πούς (''poús''), meaning "foot", is a class (biology), class of crustaceans. It comprises Anostraca, fairy shrimp, clam shrimp, Diplostraca (or Cladocera), Notostraca, the Devonian ''Lepidocaris'' and possibly the Cambrian ''Rehbachiella''. 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 arthropod mouthparts, mouthparts. This is also responsible for the name of the group (from the , gills, akin to , windpipe; , 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 and clam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean
Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthropods including decapods (shrimps, prawns, crabs, lobsters and crayfish), seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, opossum shrimps, 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 (insects and entognathans) emerged deep in the Crustacean group, with the completed pan-group referred to as Pancrustacea. The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans ( oligostracans and multicrustaceans). The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese ... [...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, with the exception of '' Branchinecta gigas,'' or "giant fairy shrimp", which is itself a predator of other species of anostracans. 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, ... [...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 routinely apply binomial Linnaean names to vertebrate and invertebrate fossils. Prior to the time of Harlan, it was common practice to publish only a genus name for a fossil animal that was new to science. 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 afte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladocera
The Diplostraca or Cladocera, commonly known as water fleas, is a superorder (biology), superorder of small, mostly freshwater crustaceans, most of which feed on microscopic chunks of organic matter, though some forms are predatory. Over 1000 species have been recognised so far, with many more undescribed species, 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, though 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 Crustacean#Structure, 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 hars ... [...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 long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
