|
Paraceraurus
''Paraceraurus'' is a genus of trilobites that lived in the Ordovician period (485.4 to 443.4 Ma). Its remains have been found in China, Estonia, Sweden and North America. These trilobites have a rounded and moderately convex ''cephalon''. '' Glabella'' is convex or flattened, with a sub-rectangular outline. Thorax shows eleven segments. Selected species * ''Paraceraurus exsul ''Paraceraurus exsul'' is a species of trilobite that lived in St. Petersburg Region and Tver Region (in erratic blocks) of Russia, Estonia, Finland (Åland, in erratic blocks), Sweden, North Germany (in erratic blocks), Lithuania and Belarus dur ...'' * '' Paraceraurus aculeatus'' * '' Paraceraurus ingricus'' * '' Paraceraurus gladiator'' * '' Paraceraurus macrophthalmus'' * '' Paraceraurus spinulosus'' References * ''Trilobite: Eyewitness to Evolution'' by Richard Fortey * Trilobites of the families Cheiruridae and Encrinuridae from Estonia.] Geoloogia Instituudi Uurimused rud Inst Geol Acad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraceraurus Spinulosus
''Paraceraurus'' is a genus of trilobites that lived in the Ordovician period (485.4 to 443.4 Ma). Its remains have been found in China, Estonia, Sweden and North America. These trilobites have a rounded and moderately convex ''cephalon''. ''Glabella'' is convex or flattened, with a sub-rectangular outline. Thorax shows eleven segments. Selected species * ''Paraceraurus exsul'' * '' Paraceraurus aculeatus'' * '' Paraceraurus ingricus'' * '' Paraceraurus gladiator'' * '' Paraceraurus macrophthalmus'' * '' Paraceraurus spinulosus'' References * ''Trilobite: Eyewitness to Evolution'' by Richard Fortey Richard Alan Fortey FRS FRSL (born 15 February 1946 in London) is a British palaeontologist, natural historian, writer and television presenter, who served as president of the Geological Society of London for its bicentennial year of 2007. Ear ... * Trilobites of the families Cheiruridae and Encrinuridae from Estonia.] Geoloogia Instituudi Uurimused rud Inst Geol Acad Sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraceraurus Exsul
''Paraceraurus exsul'' is a species of trilobite that lived in St. Petersburg Region and Tver Region (in erratic blocks) of Russia, Estonia, Finland (Åland, in erratic blocks), Sweden, North Germany (in erratic blocks), Lithuania and Belarus during the Upper Llanvirnian Stage (463.5-460.9 Ma) of the Middle Ordovician. These trilobites can reach a length of about . They show a square front edge, large genal spines on the cheeks and characteristic long pygidial spines. Genal spines are curved usually inward and upward. References * Trilobites of the families Cheiruridae and Encrinuridae from Estonia. Geoloogia Instituudi Uurimused (Trud Inst Geol Acad Sci Est SSR) Tallinn, 3 1958: 165–205, 210–212. [Zoological Record Volume 95] * V. Klikushin, A. Evdokimov, A. Pilipyuk. Ordovician Trilobites of the St. Petersburg Region, Russia. 2009. External links PaleoartFossil ID Cheiruridae Ordovician trilobites {{phacopida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheiruridae
Cheiruridae is a family of phacopid trilobites of the suborder Cheirurina. Its members, as with other members of the suborder, had distinctive pygidia modified into finger-like spines. They first appeared in the uppermost Cambrian (upper Furongian), and persisted until the end of the Middle Devonian (Givetian). Currently about 657 species assigned to 99 genera are included. Distribution The subfamily Cheirurinae with 269 species in 38 genera occur from the Floian to the Givetian and are probably monophyletic. The 109 species in 15 genera of the Acanthoparyphinae are also probably monophyletic, and are known from the Floian to the Ludfordian. The Cyrtometopinae were present between the Floian and the Upper Katian, enveloping 22 species in 5 genera, of which the monophyly is unclear. The Deiphoninae are probably monophyletic, occur from the Dapingian to the Gorstian, having 71 species assigned to 6 genera. The possibly paraphyletic Eccoptochilinae with 67 species in 13 genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
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 C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Trilobites Of North America
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 Per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Fortey
Richard Alan Fortey FRS FRSL (born 15 February 1946 in London) is a British palaeontologist, natural historian, writer and television presenter, who served as president of the Geological Society of London for its bicentennial year of 2007. Early life and education Fortey was educated at Ealing Grammar School for Boys and King's College, Cambridge, where he read Natural Sciences specialising in geology. He received a PhD and DSc from the University of Cambridge. Career Fortey has had a long career as a palaeontologist at the Natural History Museum in London; his research interests include above all, trilobites: at the age of 14, he discovered his first trilobite, sparking a passionate interest that later became a career. He has named numerous trilobite species and still continues his research despite having retired from the Museum. He studies trilobites and graptolites, especially those from the Ordovician and their systematics, evolution and modes of life; he is also involved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glabella (trilobite Anatomy)
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 crusta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
