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Dolichometopidae
Dolichometopidae is a family of corynexochid trilobites that lived in the Cambrian, from the lower Botomian to the Dresbachian The Dresbachian is a Maentwrogian regional stage of North America, lasting from 501 to 497 million years ago. It is part of the Upper Cambrian and is defined by four trilobite zones. It overlaps with the ICS-stages Guzhangian, Paibian and the lowe .... 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] |
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 referred to unofficially as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigra ... has not named the fourth stage of the Cambrian yet. In the widely used Siberian nomenclature stage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathyuriscus
''Bathyuriscus'' is an extinct genus of Cambrian trilobite. It was a nektobenthic predatory carnivore. The genus Bathyuriscus is endemic to the shallow seas that surrounded Laurentia. Its major characteristics are a large forward-reaching glabella, pointed pleurae or pleurae with very short spines, and a medium pygidium with well-impressed furrows. Complete specimens have never reached the size of 7 cm predicted by the largest pygidium found. ''Bathyuriscus'' is often found with the free cheeks shed, indicating a moulted exoskeleton. An average specimen will in addition have a furrowed glabella, crescent-shaped eyes, be semi-circular in overall body shape, have 7 to 9 thoracic segments, and a length of about 1.5 inches. Etymology ''Bathyuriscus'' is a variation of ''Bathyurus'', originally based on the Ancient Greek βαθύς (bathys) "deep", oura, "tail", thus, a trilobite with a deep tail. Distribution Species belonging to ''Bathyuriscus'' have been found in the Marju ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |