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Triarthrus Eatoni Ventral Cropped
''Triarthrus'' is a genus of Upper Ordovician ptychopariid trilobite found in New York, Ohio, Kentucky, and Indiana, eastern and northern Canada, China and Scandinavia. It is the last of the Olenid trilobites, a group which flourished in the Cambrian period. The specimens of ''T. eatoni'' that are found in the Beecher's Trilobite Bed, Rome, New York area are exquisitely preserved showing soft body parts in iron pyrite. Pyrite preservation has given scientists a rare opportunity to examine the gills, walking legs, antennae, digestive systems, and eggs of trilobites, which are rarely preserved. ''Triarthrus'' is therefore commonly used in science texts to illustrate trilobite anatomy and physiology. Distribution * ''T. beckii'' Upper Caradoc and Ashgill, Snake Hill Formation, Cohoes, New York State; and Kentucky. * ''T. billingsi'' Ashgill?, Quebec * ''T. canadensis'' is known from the Upper Ordovician of Canada (Katian, lower Member of the Whitby Formation, Craigleith vicinit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type (biology)
In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen. A taxon is a scientifically named grouping of organisms with other like organisms, a set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution. Type specimen According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the scientific name of every taxon is almost al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beecher's Trilobite Bed
Beecher's Trilobite Bed is a Konservat-Lagerstätte of Late Ordovician (Caradoc) age located within the Frankfort Shale in Cleveland's Glen, Oneida County, New York, USA.Martha Buck's senior thesis on the Beecher's Trilobite Bed Photos (and more) of trilobites from Beecher's Trilobite Bed from Yale Peabody Museum Only 3-4 centimeters thick, Beecher's Trilobite Bed has yielded numerous exceptionally preserved s with the ventral anatomy and soft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period () and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out. The last extant trilobites finally disappeared in the mass extinction at the end of the Permian about 252 million years ago. Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described. By the time trilobites first appeared in the fossil record, they were already highly diversified and geographically dispersed. Because trilobites had wide diversity and an easily fossilized exoskeleton, they left an extensive fossil record. The stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triarthrus Eatoni Ventral Cropped
''Triarthrus'' is a genus of Upper Ordovician ptychopariid trilobite found in New York, Ohio, Kentucky, and Indiana, eastern and northern Canada, China and Scandinavia. It is the last of the Olenid trilobites, a group which flourished in the Cambrian period. The specimens of ''T. eatoni'' that are found in the Beecher's Trilobite Bed, Rome, New York area are exquisitely preserved showing soft body parts in iron pyrite. Pyrite preservation has given scientists a rare opportunity to examine the gills, walking legs, antennae, digestive systems, and eggs of trilobites, which are rarely preserved. ''Triarthrus'' is therefore commonly used in science texts to illustrate trilobite anatomy and physiology. Distribution * ''T. beckii'' Upper Caradoc and Ashgill, Snake Hill Formation, Cohoes, New York State; and Kentucky. * ''T. billingsi'' Ashgill?, Quebec * ''T. canadensis'' is known from the Upper Ordovician of Canada (Katian, lower Member of the Whitby Formation, Craigleith vicinit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triarthrus Becki
''Triarthrus'' is a genus of Upper Ordovician ptychopariid trilobite found in New York, Ohio, Kentucky, and Indiana, eastern and northern Canada, China and Scandinavia. It is the last of the Olenid trilobites, a group which flourished in the Cambrian period. The specimens of ''T. eatoni'' that are found in the Beecher's Trilobite Bed, Rome, New York area are exquisitely preserved showing soft body parts in iron pyrite. Pyrite preservation has given scientists a rare opportunity to examine the gills, walking legs, antennae, digestive systems, and eggs of trilobites, which are rarely preserved. ''Triarthrus'' is therefore commonly used in science texts to illustrate trilobite anatomy and physiology. Distribution * ''T. beckii'' Upper Caradoc and Ashgill, Snake Hill Formation, Cohoes, New York State; and Kentucky. * ''T. billingsi'' Ashgill?, Quebec * ''T. canadensis'' is known from the Upper Ordovician of Canada (Katian, lower Member of the Whitby Formation, Craigleith vicinit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Transgression
A marine transgression is a geologic event during which sea level rises relative to the land and the shoreline moves toward higher ground, which results in flooding. Transgressions can be caused by the land sinking or by the ocean basins filling with water or decreasing in capacity. Transgressions and regressions may be caused by tectonic events such as orogenies, severe climate change such as ice ages or isostatic adjustments following removal of ice or sediment load. During the Cretaceous, seafloor spreading created a relatively shallow Atlantic basin at the expense of deeper Pacific basin. That reduced the world's ocean basin capacity and caused a rise in sea level worldwide. As a result of the sea level rise, the oceans transgressed completely across the central portion of North America and created the Western Interior Seaway from the Gulf of Mexico to the Arctic Ocean. The opposite of transgression is regression in which the sea level falls relative to the land and expo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladogram Triathrus Clade
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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