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Aglaspid
Aglaspidida is an extinct order of aquatic arthropods that were once regarded as primitive chelicerates. However, anatomical comparisons demonstrate that the aglaspidids cannot be accommodated within the chelicerates, and that they lie instead within the Artiopoda, thus placing them closer to the trilobites. Aglaspidida contains the subgroups Aglaspididae and Tremaglaspididae, which are distinguished by the presence of acute/spinose genal angles and a long spiniform tailspine in the Aglaspididae. Aglaspidid fossils are found in North America (upper Mississippi valley, Missouri and Utah), Europe, Australia, and China. Certain other artiopods are believed to be closely related to the aglaspidids, including the order Strabopida, which includes the genera '' Strabops'', ''Paleomerus ''Paleomerus'' is a genus of strabopid, a group of extinct arthropods. It has been found in deposits from the Cambrian period (Atdabanian epoch). It is classified in the family Strabopidae of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beckwithia Typa
''Beckwithia'' is an extinct genus of average to large size ( to ), soft bodied artiopodan arthropods that lived during the late Middle and Upper Cambrian on the former paleocontinent Laurentia, in what are now Utah and Wisconsin. It has an inverted egg-shape, with a semi-circular head, 11 abdominal segments and a tail spine. It is a typical member of the group Aglaspidida. Etymology ''Beckwithia '' was named after Frank Beckwith, editor and publisher of the Millard County Chronicle of Delta, Utah in the early to middle 1900s, who had a passion for trilobites. Distribution ''Beckwithia'' has been collected from the Middle and Upper Cambrian of Utah (Weeks Formation, House Range, Millard County) and from the Franconian (in North-America called Sunwaptan) of Wisconsin. Taxonomic history ''Beckwithia'' was previously placed in a separate family, the Beckwithiidae, but it has now been established that the defining character (that the terminal segments appeared to be fused) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beckwithia (arthropod)
''Beckwithia'' is an extinct genus of average to large size ( to ), soft bodied artiopodan arthropods that lived during the late Middle and Upper Cambrian on the former paleocontinent Laurentia, in what are now Utah and Wisconsin. It has an inverted egg-shape, with a semi-circular head, 11 abdominal segments and a tail spine. It is a typical member of the group Aglaspidida. Etymology ''Beckwithia '' was named after Frank Beckwith, editor and publisher of the Millard County Chronicle of Delta, Utah in the early to middle 1900s, who had a passion for trilobites. Distribution ''Beckwithia'' has been collected from the Middle and Upper Cambrian of Utah (Weeks Formation, House Range, Millard County) and from the Franconian (in North-America called Sunwaptan) of Wisconsin. Taxonomic history ''Beckwithia'' was previously placed in a separate family, the Beckwithiidae, but it has now been established that the defining character (that the terminal segments appeared to be fused) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australaglaspis
''Australaglaspis stoneyensis'' is an aglaspid that superficially resembles a horseshoe crab, or trilobite. It is known from Idamean-aged strata (Late Cambrian) at Stoney Point in north-west Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi .... References Aglaspidida Prehistoric arthropod genera Prehistoric arthropods of Australia Invertebrates of Tasmania {{paleo-arthropod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopites
''Cyclopites'' is a genus of aglaspidid arthropods that lived in shallow seas in what is now Wisconsin during Late Cambrian 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 ... times. It is distinguished from other aglaspidids by the extreme proximity of its eyes. The genus earns its name from this presence of what might appear to be a single, central eye.Hesselbo, S.P. (1992) Aglaspidida (Arthropoda) from the Upper Cambrian of Wisconsin. Journal of Paleontology 66: 885–923 References * Aglaspidida Cambrian arthropods of North America {{paleo-arthropod-stub Cambrian genus extinctions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artiopoda
The Artiopoda is a grouping of extinct arthropods that includes trilobites and their close relatives. It was erected by Hou and Bergström in 1997 to encompass a wide diversity of arthropods that would traditionally have been assigned to the Trilobitomorpha. Hou and Bergström used the name Lamellipedia as a superclass to replace Trilobitomorpha that was originally erected at the subphylum level, which they considered inappropriate. Trilobites, in part due to their mineralising exoskeletons, are by far the most diverse and long lived members of the clade, with most records of other members, which lack mineralised exoskeletons, being from Cambrian deposits. Description According to Stein and Selden (2012) artiopods are recognised by the possession of filiform antennulae, limbs with bilobate exopods, with the proximal lobe being elongate and bearing a lamella, while the distal lobe is paddle-shaped and setiforous (bearing hair-or bristle like structures). The limb endopod has se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelicerate
The subphylum Chelicerata (from New Latin, , ) constitutes one of the major subdivisions of the phylum Arthropoda. It contains the sea spiders, horseshoe crabs, and arachnids (including harvestmen, scorpions, spiders, solifuges, ticks, and mites, among many others), as well as a number of extinct lineages, such as the eurypterids (sea scorpions) and chasmataspidids. The Chelicerata originated as marine animals in the Middle Cambrian period; the first confirmed chelicerate fossils, belonging to '' Sanctacaris'', date from 508 million years ago. The surviving marine species include the four species of xiphosurans (horseshoe crabs), and possibly the 1,300 species of pycnogonids (sea spiders), if the latter are indeed chelicerates. On the other hand, there are over 77,000 well-identified species of air-breathing chelicerates, and there may be about 500,000 unidentified species. Like all arthropods, chelicerates have segmented bodies with jointed limbs, all covered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aglaspoides
''Aglaspoides'' is an extinct genus of aglaspid arthropod. External links ''Aglaspoides''at the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database (PBDB) originated in the NCEAS-funded Phanerozoic Marine Pale ... Aglaspidida {{Paleo-arthropod-stub ... [...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] |
Palaeontology (journal)
''Palaeontology'' is one of the two scientific journals of the Palaeontological Association (the other being '' Papers in Palaeontology''). It was established in 1957 and is published on behalf of the Association by Wiley-Blackwell. The editor-in-chief is Barry Lomax (University of Nottingham). ''Palaeontology'' publishes articles on a range of palaeontological topics, including taphonomy, functional morphology, systematics, palaeo-environmental reconstruction and biostratigraphy. According to the ''Journal Citation Reports'', the journal has a 2017 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 3.730, ranking it 1st out of 55 journals in the category "Paleontology". References External links * Paleontology journals Publications established in 1957 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Plate, North American Tectonic Plate, Greenland is included as a part of North America geographically. North America covers an area of about , about 16.5% of Earth's land area and about 4.8% of its total surface. North America is the third-largest continent by area, following Asia and Africa, and the list of continents and continental subregions by population, fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in List of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's population. In Americas (terminology)#Human ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladistics (journal)
''Cladistics'' is a bimonthly peer-reviewed scientific journal which has published research in cladistics since 1985. It is published by Wiley-Blackwell on behalf of the Willi Hennig Society. ''Cladistics'' publishes papers relevant to evolution, systematics, and integrative biology. Papers of both a conceptual or philosophical nature, discussions of methodology, empirical studies on taxonomic groups from animals to bacteria, and applications of systematics in disciplines such as genomics, paleontology and biomedical epidemiology are accepted. Five types of paper appear in the journal: reviews, regular papers, forum papers, letters to the editor, and book reviews. According to the ''Journal Citation Reports'', the journal has a 2020 impact factor of 5.254, ranking it 10th out of 50 journals in the category "Evolutionary Biology". Its editor-in-chief An editor-in-chief (EIC), also known as lead editor or chief editor, is a publication's editorial leader who has final responsibi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genal Angle
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 stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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