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Ptychopariida Genera
Ptychopariida is a large, heterogeneous order of trilobite containing some of the most primitive species known. The earliest species occurred in the second half of the Lower Cambrian, and the last species did not survive the Ordovician–Silurian extinction event. Trilobites have facial sutures that run along the margin of the glabella and/or fixigena to the shoulder point where the cephalon meets the thorax. These sutures outline the cranidium, or the main, central part of the head that does not include the librigena (free cheeks). The eyes are medial along the glabella on the suture line (and some species have no eyes). The fossils of the moults of trilobites can often be told from the fossils of the actual animals by whether the librigena are present. (The librigena, or cheek spines, detach during moulting.) In ptychopariids, short bladelike genal spines are often present on the tips of the librigena. The thorax is large and is typically made up of eight or more segments. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elrathia Kingii
''Elrathia'' is a genus of trilobite belonging to Ptychopariacea known from the mid-Cambrian of Laurentia (North America). ''E. kingii'' is one of the most common trilobite fossils in the USA locally found in extremely high concentrations within the Wheeler Formation in the U.S. state of Utah. ''E. kingii'' has been considered the most recognizable trilobite. Commercial quarries extract ''E. kingii'' in prolific numbers, with just one commercial collector estimating 1.5 million specimens extracted in a 20-year career. 1950 specimens of ''Elrathia'' are known from the Greater Phyllopod bed, where they comprise 3.7% of the community. Etymology Even though the generic name ''Elrathia'' was first published in the combination ''E. kingii'', a species from the House Range, Utah, the name, itself, is derived from Elrath, Cherokee County, Alabama. Description ''E. kingii'' is a medium-sized trilobite with a smooth sub-ovate carapace that is tapered towards the rear. Thorax is usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Damesellidae
Damesellidae is a family of odontopleurid trilobites found in late Middle to Late Cambrian marine strata, primarily of China. Damesellids are closely related to the odontopleurids of Odontopleuridae, but are not nearly as spinose, nor possess spines as exaggerated as Odontopleuridae. Like Odontopleuridae odontopleurids, damesellids have broad, bar-shaped cranidia with ledge-like borders. Damesellidae may represent transitional forms between more primitive, possibly ancestral ptychopariids and more advanced odontopleurids. Genera Genera include *?'' Adelogonus'' *'' Bergeronites'' *'' Blackwelderia'' *'' Blackwelderioides'' *'' Chiawangella'' *'' Cyrtoprora'' *'' Damesella'' *'' Damesops'' *'' Dipentaspis'' *'' Dipyrgotes'' *'' Neodrepanura'' *'' Duamsannella'' *'' Fengduia'' *'' Guancenshania'' *?'' Hercantyx'' *''Histiomona ''Histiomona'' is an extinct genus of damesellid odontopleurid trilobite. It lived from 501 to 490 million years ago during the Dresbachian faunal s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptychopariina
Ptychopariina is an extinct suborder of trilobites of the order Ptychopariida.Swinnerton HH, 1915. Suggestions for a Revised Classification of trilobites. ''Geological Magazine''. Also known as the ''primitive Ptychopariida'', they are a notably wide and varied taxon. Some of the representative genera include ''Elrathia'', '' Densonella'', '' Norwoodia'', '' Tricrepicephalus'', '' Conocoryphe'', and '' Modocia''. Description Specialization Specialization or Specialized may refer to: Academia * Academic specialization, may be a course of study or major at an academic institution or may refer to the field in which a specialist practices * Specialty (medicine), a branch of medical ... is common in the Ptychopariina, which has made it difficult for authors to develop a single type that can distinguish Ptychopariina from other clades. The thorax tends to be relatively long, with the pygidium generally smaller in size than the thorax. References External links''Ptychopariid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triarthrus
''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 vicinity, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olenidae
Olenidae is a family of ptychopariid trilobites. Some genera, ''Balnibarbi'' and ''Cloacaspis'', are thought to have evolved a symbiotic relationship with sulfur-eating bacteria from which they derived nutrition. Genera * Acerocare * Acerocarina * Aciculolenus *Anaximander * Angelina = Keidelaspis), * Apoplanias * Asilluchus * Baikonuraspis *Balnibarbi * Bienvillia (= Diatemnus; = Mendoparabolina) * Boeckaspis (/Boeckia BROGGER; = Sphaerophthalmella) * Bondarevites * Bulbolenus * Chekiangaspis *Cloacaspis * Ctenopyge * Cyclognathina * Danarcus * Desmetia * Eoctenopyge * Euonchonotina * Eurycare * Granitzia * Hancrania * Helieranella * Highgatella * Huangshiaspis * Hunanolenus * Hypermecaspis (= Spitsbergaspis), * Inkouia (= Agalatus), * Isidrella * Jujuyaspis (= Alimbetaspis), * Leiobienvillia * Leptoplastides (= Andesaspis;= Beltella; = Chunkingaspis; = Parabolinopsis; * Rampartaspis), * Leptoplastus * Leurostega * Magnomma * Mesoctenopyge * Moxomia * Neoolenus * Neoparabolin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
