Sinijanella
''Sinijanella'' is a genus of corynexochid trilobites that lived during the early part of the Botomian stage of the Cambrian Period The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovici .... , which lasted from approximately . References Corynexochida genera Dolichometopidae Cambrian trilobites Cambrian trilobites of Asia Cambrian trilobites of Europe {{Corynexochida-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Corynexochida
Corynexochida is an order of trilobite that lived from the Lower Cambrian to the Late Devonian. Like many of the other trilobite orders, Corynexochida contains many species with widespread characteristics. Description The middle region of the cephalon (arthropod anatomy), cephalon (the glabella) is typically elongate, with the sides often spreading forward (pestle-shaped). Some species have glabellae that are ''effaced'', meaning they are smooth and show little detail. The glabellar furrows (when not effaced) typically have a splayed arrangement. In most species, the hind pair on either side of the cephalon become spines that point sharply backwards, and the spinose tips of the anterior pairs of thoracic segments tend to become more and more forward directed toward the pygidium. The eyes are typically large. Pygidia are typically large, competing in size with the cephalon in some species. The tips of the thoracic segments of many Corynexochida species are spine-like (though in ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Dolichometopidae
Dolichometopidae is a family of corynexochid trilobites that lived in the Cambrian, from the lower Botomian Cambrian Stage 4 is the still unnamed fourth stage of the Cambrian and the upper stage of Cambrian Series 2. It follows Cambrian Stage 3 and lies below the Wuliuan. The lower boundary has not been formally defined by the International Commission ... to the Dresbachian. It contains the following genera: *'' Aegunaspis'' *'' Amphoton'' *'' Anoria'' *'' Asperocare'' *'' Athabaskia'' *'' Athabaskiella'' *'' Atypicus'' *'' Basanellus'' *'' Bathyuriscidella'' *'' Bathyuriscus'' *'' Borovikovia'' *'' Centonella'' *'' Chilometopus'' *'' Chilonorria'' *'' Clavaspidella'' *'' Corynexochides'' *'' Deiradonyx'' *'' Dolicholeptus'' *'' Dolichometopsis'' *'' Dolichometopus'' *'' Drozdoviella'' *'' Erratobalticus'' *'' Ezhuangia'' *'' Fuchouia'' *'' Glossopleura'' *''? Granularaspis'' *'' Guraspis'' *''? Hanburia'' *'' Hemirhodon'' *'' Horonastes'' *'' Itydeois'' *'' Kannoriella'' *' ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. Phylogeneti ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Trilobite
Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most successful of all early animals, existing in oceans for almost 270million years, with over 22,000 species having been described. Because trilobites had wide diversity and an easily fossilized mineralised exoskeleton made of calcite, they left an extensive fossil record. The study of their fossils has facilitated important contributions to biostratigraphy, paleontology, evolution, evolutionary biology, and plate tectonics. Trilobites are placed within the clade Artiopoda, which includes many organisms that are morphologically similar to trilobites, but are largely unmineralised. The relationship of Artiopoda to other arthropods is uncertain. Trilobites evolved into many ecological niches; some moved over the seabed as predators, scavengers, or ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Botomian
Cambrian Stage 4 is the still unnamed fourth stage of the Cambrian and the upper stage of Cambrian Series 2. It follows Cambrian Stage 3 and lies below the Wuliuan. The lower boundary has not been formally defined by the International Commission on Stratigraphy. One proposal is the first appearance of two trilobite genera, '' Olenellus'' or '' Redlichia''. Another proposal is the first appearance of the trilobite species '' Arthricocephalus chauveaui''. Both proposals will set the lower boundary close to million years ago. The upper boundary corresponds to the beginning of the Wuliuan. Naming The International Commission on Stratigraphy The International Commission on Stratigraphy (ICS), sometimes unofficially referred to as the International Stratigraphic Commission, is a daughter or major subcommittee grade scientific organization that concerns itself with stratigraphy, strati ... has not named the fourth stage of the Cambrian yet. In the widely used Siberian nomenclature ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cambrian Period
The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 486.85 Ma. Most of the continents lay in the southern hemisphere surrounded by the vast Panthalassa, Panthalassa Ocean. The assembly of Gondwana during the Ediacaran and early Cambrian led to the development of new Convergent boundary, convergent plate boundaries and Volcanic arc, continental-margin arc magmatism along its margins that helped drive up global temperatures. Laurentia lay across the equator, separated from Gondwana by the opening Iapetus Ocean. The Cambrian marked a profound change in Life, life on Earth; prior to the Period, the majority of living organisms were small, Unicellular organism, unicellular and poorly preserved. Complex, multicellular organisms gradually became more common during the Ediacaran, but it ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |