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Peronopsis
''Peronopsis'' (meaning "broach-like" or possibly "boot-like") is a genus of trilobite restricted to the Middle Cambrian. Its remains have been found in Asia, Australia, Europe, and North America. Etymology The subgenus ''Svenax'' is a contraction of Sven Axel, the given names of the paleontologist Tullberg. Taxonomy Position of ''Peronopsis palmadon'' ''Peronopsis palmadon'' is intermediate between Peronopsidae and Condylopygidae, but it is not clear whether ''P. palmadon'' is ancestral to the Condylopigidae, a condylopigid exhibiting regression towards ancestral characters, or an example of parallel evolution. Species previously assigned to ''Peronopsis'' * ''P. acadica'' = '' Acadagnostus acadicus'' * ''P. bifidus'' = '' Pseudoperonopsis bifidus'' * ''P. bonnerensis'' = '' Pentagnostus (Meragostus) bonnerensis'' * ''P. brunfloensis'' = '' Redeagnostus brunfloensis'' * ''P. bulkurensis'' = '' Pentagnostus (Meragostus) bulkurensis'' * ''P. columbensis'' = '' Pseudo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peronopsidae
The Peronopsidae (which may also be called peronopsids) comprise the earliest family of the Agnostina suborder. Species of this family occurred on all paleocontinents. The earliest representatives of this family first occur just before the start of the Middle Cambrian, and the last disappeared just after the start of the Upper Cambrian. Distribution Peronopsidae are cosmopolitan. Temporal distribution Temporal distribution: * '' Archaeagnostus'', Toyonian ( ''Nephrolenellus multinodus''-zone) and Amgaian ('' Ovatoryctocara''-zone). * '' Eoagnostus'', Toyonian (''Nephrolenellus multinodus''-zone) and Amgaian (''Ovatoryctocara''-zone). * '' Peronopsis (Proacadagnostus)'', Amgaian (''Ovatoryctocara''- and lower ''Kounamkites''-zones). * '' Diplorrhina'', Amgaian (''Ovatoryctocara''- and ''Kounamkites''-zones) * '' Peronopsis (Peronopsis)'', Amgaian (''Ovatoryctocara''-, ''Kounamkites''- and ''Triplagnostus gibbus''-zones). * '' Pentagnostus (Pentagnostus)'', Amgaian (''Ovator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplorrhina
''Diplorrhina'' Hawle and Corda (1847) is a genus of trilobite belonging to Order Agnostida. It lived during the early Middle Cambrian ( Amgan and Mayan stages) in what are now the Czech Republic and the North Siberian plateau. as in members of the family Peronopsidae it lacks a preglabellar furrow. Both cephalon and pygidium lack spines. It is difficult to distinguish ''Diplorrhina'' from many other peronopsids. Taxonomy The ancestor of ''Diplorrhina'' is most likely one of the Siberian species of the genus ''Archaeagnostus ''Archaeagnostus'' is an extinct genus from a well-known class of fossil marine arthropods, the trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest ...''. ''D. recta'' is the most primitive species and it gave rise to ''D. cuneifera'', which was in turn ancestral to ''Diplorrhina triplicata''. Species previously assigned to ''Diplorrhina'' * ''D. normat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acadagnostus
''Acadagnostus'' is a genus of trilobite from the Middle Cambrian, with 7 species currently recognized. The type species ''A. acadicus'' has the widest distribution known from any peronopsid (with ''Peronopsis, Peronopsis integer'' and ''P. scutalis'') and has been found in North America, Greenland, England, Western Europe, Eastern Europe, Central Asia, the Altai Mountains, the Siberian shield, China, and Australia. Etymology * ''ancisa'' is Latin meaning 'cut round', referring to the shape of the rear pygidial margin. * ''australis'' is Latin for 'southern'. * ''certus'' is Latin meaning 'definite' or 'sure'. * ''syrma'' is Ancient Greek meaning 'robe with a train', indicating the wide pygidial border in the rear. Description Like all Agnostida, ''Acadagnostus'' is diminutive, with the headshield (or Cephalon (arthropod head)#Trilobites, cephalon) and tailshield (or pygidium) of approximately the same size (or Pygidium#Trilobites, isopygous) and outline. Like all Agnostina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Itagnostus
''Itagnostus'' is a genus of trilobite restricted to the Middle Cambrian. Its remains have been found in Asia, Australia, Europe, and North America. Distribution * ''Itagnostus elkedrensis'' occurs in the Middle Cambrian of Australia (''Ptychagnostus praecurrens''-zone, ''Xystridura templetonensis''-zone, and ''Dinesus''-stage, Elkedra; ''Triplagnostus gibbus''-zone, Sandover Beds; both Northern Territory), the Russian Federation (''Kounamkites''-zone, Nekekit River; ''Liostracus allachjunensis''-zone, Lena River). * ''Itagnostus comis'' is found in the Middle Cambrian of Australia (''Triplagnostus gibbus''-zone, Sandover Beds, Northern Territory). * ''Itagnostus gaspensis gaspensis'' is reported from the Middle Cambrian of the United States (Geddes Formation, Nevada; ''Ptychagnostus atavus''-zone, Wheeler Formation, Drum Mountains, Utah), Canada (upper part, Grosses Roches, St. Laurence, Quebec), Russian Federation (''Tomagnostus fissus''-zone, Lena River). * ''Itagnostus gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condylopygidae
The Condylopygidae Raymond (2013) RAYMOND, P. E., 1913: Some changes in the names of genera of trilobites. ''The Ottawa Naturalist'', 26: 137−142. are a family of small trilobites that lived during the Middle Cambrian, and found in Canada (Newfoundland and Nova Scotia), the Czech Republic, Germany, France, Spain, England, Wales, Sweden, and the Russian Federation (Siberia). They uniquely differ from all other Agnostina in having the frontal glabellar lobe wider than the rear lobe. The Condylopygidae are the only family assigned to the Condylopygoidea superfamily. Taxonomy The Condylopygoidea are an isolated branch in the Agnostina suborder that occur approximately contemporaneously with the Peronopsidae, the earliest representatives of the main branch of the Agnostina. One species, ''Peronopsis palmadon'', appears intermediate between Peronopsidae and Condylopygidae, but it is not clear whether ''P. palmadon'' is ancestral to the Condylopygidae - a regression towards ancest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentagnostus
''Pentagnostus'' is a genus of trilobites restricted to the Middle Cambrian. Its remains have been found in Siberia, Australia, North America, Scandinavia, and Kazakhstan. Taxonomy The probable ancestor of ''Pentagnostus'' is Archaeagnostus. Two subgenera can be distinguished. The nominate subgenus occurred first and developed into the later subgenus ''Pentagnostus (Meragnostus)'' and the family Ptychagnostidae Ptychagnostidae is a family of agnostid trilobites from the 5th Stage to the Paibian Age of the Cambrian ( to million years ago). The family includes several important index fossils. Description Like all agnostids, ptychagnostids have cep .... Species and distribution Subgenus ''Pentagnostus (Pentagnostus)'' * ''P. anabarensis'' Lermontova, 1940 ( type) * ''P. ademptus'' (Prokovskaya and Jegorova, 1972) * ''P. brighamensis'' (Resser, 1938) * ''P. shergouldi'' Laurie, 2004 * ''P. veles'' Öpik, 1979 synonym ''P. endemicus''. Subgenus ''Pentagnostus (Mera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeagnostus
''Archaeagnostus'' is an extinct genus from a well-known class of fossil marine arthropods, the 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 ...s. It lived from the terminal Toyonian to early Amgaian. Species belonging to this genus have been found in Eastern North America, Newfoundland, the Henson Gletscher Formation in Greenland, the Nekekit and Molodo Rivers in Eastern Siberia, and in Guizhou, China. References Cambrian trilobites of North America Peronopsidae Agnostida genera Extinct animals of North America Cambrian trilobites of Asia Paleozoic life of Quebec {{agnostida-stub Cambrian genus extinctions ... [...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] |
Agnostidae
Agnostidae is a family of Agnostida trilobites. Like all Agnostina, they were eyeless and bore only two thoracic segments. They ranged in benthic waters across the globe from 508 to 461 million years ago, containing the following genera, among others: *'' Acmarhachis'' *''Agnostus ''Agnostus'' is a genus of agnostid trilobites, belonging to the family Agnostidae, that lived during the late Middle Cambrian – early Upper Cambrian (about 506 to 492 million years ago). It is the type genus of the family Agnostidae and is sub ...'' *'' Aistagnostus'' *'' Anglagnostus'' *'' Biciragnostus'' *'' Connagnostus'' *'' Distagnostus'' *'' Eolotagnostus'' *'' Gymnagnostus'' *'' Homagnostus'' *'' Idolagnostus'' *'' Innitagnostus'' *'' Ivshinagnostus'' *'' Kymagnostus'' *'' Lotagnostus'' *'' Micragnostus'' *'' Obelagnostus'' *'' Oncagnostus'' *'' Peronopsis'' *'' Phalacroma'' *'' Phalagnostus'' *'' Quadrahomagnostus'' *'' Raragnostus'' *'' Semagnostus'' *'' Strictagnostus'' *'' Trilobagnostu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mayan Stage
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established as "Cambrian series" by Adam Sedgwick, who named it after Cambria, the Latin name for 'Cymru' (Wales), where Britain's Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large "Transition Series", although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadragnostus
''Quadragnostus'' is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the Cambrian Period The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ..., which lasted from approximately 539 to 485 million years ago. References Cambrian trilobites Peronopsidae Agnostida genera {{agnostida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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