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Illaenus Crassicauda
''Illaenus crassicauda'' is a species of trilobites belonging to the family Illaenidae. These trilobites lived in the middle Ordovician and in the Silurian age (443 - 418 million years ago). Fossils of this species have been found in the sediments of Sweden and Russia. Etymology The Latin species name ''crassicauda'' means "fat-tailed", with reference to the shape of the pygidium. Description ''Illaenus crassicauda'' can reach a length of about . These trilobites are without glabella and without articulation of the tail. The cephalon Cephalon, Inc. was an American biopharmaceutical company co-founded in 1987 by pharmacologist Frank Baldino, Jr., neuroscientist Michael Lewis, and organic chemist James C. Kauer—all three former scientists with the DuPont Company. Baldino s ... has a high profile. The large bulbous head are distant from the axis of the head, close to the margin. References * V. JaanussonZur Fauna und zur Korrelation der Kalksteine mit Illaenus crassic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sweden
Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, Finland to the east, and is connected to Denmark in the southwest by a bridgetunnel across the Öresund. At , Sweden is the largest Nordic country, the third-largest country in the European Union, and the fifth-largest country in Europe. The capital and largest city is Stockholm. Sweden has a total population of 10.5 million, and a low population density of , with around 87% of Swedes residing in urban areas in the central and southern half of the country. Sweden has a nature dominated by forests and a large amount of lakes, including some of the largest in Europe. Many long rivers run from the Scandes range through the landscape, primarily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galerie De Paléontologie Et D'anatomie Comparée
The Gallery of Paleontology and Comparative Anatomy (in French, ''galerie de Paléontologie et d'Anatomie comparée'') is a part of the French National Museum of Natural History (''Muséum national d'histoire naturelle'', MNHN). It is situated in the '' Jardin des plantes'' in Paris near the Gare d'Austerlitz. The Gallery of Comparative Anatomy (occupying the ground floor), holds nearly a thousand skeletons and interprets their organization and classification. The Gallery of Paleontology (occupying the first and second floor) presents a famous collection of fossil vertebrates, fossil invertebrates and fossil plants. Among the most appreciated pieces by the public is worth mentioning a series of dinosaur skeleton casts (''Diplodocus'', ''Iguanodon'', ''Allosaurus'', ''Carnotaurus'', ''Tarbosaurus'', ''Unenlagia'', ''Dromaeosaurus'', '' Bambiraptor'') but also a ''Tyrannosaurus'' skull (cast of specimen AMNH 5027), an authentic skull of ''Triceratops'', an authentic ''Compsognathu ... [...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] |
Illaenidae
The Illaenidae are a family of trilobites in the order Corynexochida. 223 currently accepted species in 24 genera are known from the Ordovician. Some scholars include the Panderiidae in the Illaenidae, but this is not generally supported. Distribution ''Illaenus? priscus'' from Salair and ''Illaenus? berkutensis'' from the Malyi Karatau, Kazakhstan (both Lower Tremadocian), are both very poorly known and it remains uncertain to which family they could best be assigned. The first certain Illaenid is ''I. hinomotoensis'' from the Upper Tremadocian of North China and South Korea. The earliest species known from Laurentia (western Ireland) is ''I. weaveri'', probably latest Floian. These early occurrences are from the tropics, but during the Darriwilian the family spread over southern Gondwana, and became cosmopolitan for the remainder of the Ordovician, although most genera had limited distributions. The genus ''Stenopareia'' survived the Ordovician–Silurian extinction events an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Union of Geological Sciences, Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pygidium
The pygidium (plural pygidia) is the posterior body part or shield of crustaceans and some other arthropods, such as insects and the extinct trilobites. In groups other than insects, it contains the anus and, in females, the ovipositor. It is composed of fused body segments, sometimes with a tail, and separated from thoracic segments by an articulation.Shultz, J.W. (1990). Evolutionary Morphology And Phylogeny of Arachnida. Cladistics 6: 1–38. Chelicerates In arachnids, the pygidium is formed by reduction of the last three opisthosomal segments to rings where there is no distinction between tergites and sternites. A pygidium is present in Palpigradi, Amblypygi, Thelyphonida, Schizomida, Ricinulei and in the extinct order Trigonotarbida. It is also present in early fossil representatives of horseshoe crabs. Trilobites In trilobites, the pygidium can range from extremely small (much smaller than the head, or cephalon) to larger than the cephalon. They can be smooth, as in order ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalon (arthropod Head)
The cephalon is the head section of an arthropod. It is a tagma, i.e., a specialized grouping of arthropod segments. The word cephalon derives from the Greek κεφαλή (kephalē), meaning "head". Insects In insects, ''head'' is a preferred term. The insect head consists of five segments, including three (the labial, maxillary and mandibular) necessary for food uptake, which are altogether known as the gnathocephalon and house the suboesophageal ganglion of the brain, as well as the antennal segment, and an ocular segment, as well as a non segmented fused section of the head where the archicerebrum is housed known as the acron. See also arthropod head problem. Chelicerates and crustaceans In chelicerates and crustaceans, the cephalothorax is derived from the fusion of the cephalon and the thorax, and is usually covered by a single unsegmented carapace. In relation with the arthropod head problem, phylogeny studies show that members of the Malacostraca class of cru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valdar Jaanusson
Valdar Jaanusson (1923–1999) was an Estonian-Swedish geologist. In 1960 he introduced the concept of topostratigraphy into Swedish stratigraphy. A recognized expert on the geology of the Ordovician period, he was member of the Estonian Academy of Sciences Founded in 1938, the Estonian Academy of Sciences ( et, Eesti Teaduste Akadeemia) is Estonia's national academy of science in Tallinn. As with other national academies, it is an independent group of well-known scientists whose stated aim is to .... Dagens Nyheter. References 1923 births 1999 deaths[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Trilobites
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian Pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Trilobites Of Europe
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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