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Martinssonia
''Martinssonia'' is an extinct genus of Cambrian arthropod from the Orsten Lagerstätte. Description ''Martinssonia'' is a small (roughly 1.5 mm long) arthropod, with eight pairs of appendages and ten segments including the eyeless head. It has a pair of antennae, twelve biramous appendages on its head and front two body segments and a final pair of uniramous appendages on its third segment. ''Martinssonia'' also seems to have a pleotelson The telson () is the hindmost division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment of the arthropod body, or an additional division that is not a true segment on account of ..., similar to modern crustacean larvae. Ecology ''Martinssonia'' was presumably a benthic detritivore, stirring up food particles from the seafloor. Etymology ''Martinssonia'' is named for Anders Martinsson, a former Professor of Palaeobiology at Uppsala University in Sweden. The specie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Musacaris
''Musacaris '' is an extinct genus of Cambrian arthropod from the Orsten Lagerstätte, formerly synonymous with ''Martinssonia''. It contains only a single species, ''Musacaris gerdgeyeri''. Description ''Musacaris'' is a small (roughly 0.8 mm long), unsegmented arthropod, with four pairs of appendages. It has a pair of antennae, and three pairs of biramous appendages. It also has an unusual projection on its head, possibly the future position of the mouth. The unsegmented body suggests all current specimens of ''Musacaris'' may be so-called "head larvae". The five developmental stages are quite similar, with the same amount and positioning of the limbs. Currently, ''Musacaris'' is thought to be a basal mandibulate or stem-crustacean, possibly sister to labrophorans (Crustacea and Phosphatocopina Phosphatocopina (alternatively Phosphatocopida) is an extinct group of bivalved arthropods known from the Cambrian period. They are generally sub-milimetric to a few millimetr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orsten
The Orsten fauna are fossilized organisms preserved in the Orsten lagerstätte of Cambrian (Late Miaolingian to Furongian) rocks, notably at Kinnekulle and on the island of Öland, all in Sweden. The initial site, discovered in 1975 by Klaus Müller and his assistants, exceptionally preserves soft-bodied organisms, and their larvae, who are preserved uncompacted in three dimensions. The fossils are phosphatized and silicified, thus the delicate chitinous cuticle and soft parts are not affected by acids, which act upon the limestone nodules within which the fossils have survived. Acids dissolve the limestone, revealing the microfossils in a recovery process called "acid etching". To recover the fossils, more than one and a half tons of Orsten limestone have been dissolved in acid, originally in a specifically designed laboratory in Bonn, more recently moved to Ulm. The insoluble residue is scanned by electron microscope. The phosphorus used to replace the fossils with calcium p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagerstätte
A Fossil-Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that preserves an exceptionally high amount of palaeontological information. ''Konzentrat-Lagerstätten'' preserve a high concentration of fossils, while ''Konservat-Lagerstätten'' offer exceptional fossil preservation, sometimes including preserved soft tissues. ''Konservat-Lagerstätten'' may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus delaying the decomposition of both gross and fine biological features until long after a durable impression was created in the surrounding matrix. ''Fossil-Lagerstätten'' spans geological time from the Neoproterozoic era to the present. Worldwide, some of the best examples of near-perfect fossilization are the Cambrian Maotianshan shales and Burgess Shale, the Ordovician Soom Shale, the Silurian Waukesha Biota, the Devonian Hunsrück Slates and Gogo Formation, the Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biramous
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip, : ''coxae''), ''trochanter'', ''femur'' (: ''femora''), ''tibia'' (: ''tibiae''), ''tarsus'' (: ''tarsi''), ''ischium'' (: ''ischia''), ''metatarsus'', ''carpus'', ''dactylus'' (meaning finger), ''patella'' (: ''patellae''). Homologies of leg segments between groups are difficult to prove and are the source of much argument. Some authors posit up to eleven segments per leg for the most recent common ancestor of extant arthropods but modern arthropods have eight or fewer. It has been argued that the ancestral leg need not have been so complex, and that other events, such as successive loss of function of a ''Hox''-gene, could result in parallel gains of leg segments. In arthropods, each of the leg segments articulates with the next seg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telson
The telson () is the hindmost division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment (biology), segment of the arthropod body, or an additional division that is not a true segment on account of not arising in the embryo from teloblast areas as other segments. It never carries any appendages, but a forked "tail" called the caudal furca may be present. The shape and composition of the telson differs between arthropod groups. Crustaceans In lobsters, Caridea, shrimp and other Decapoda, decapods, the telson, along with the uropods, forms the tail fan. This is used as a paddle in the caridoid escape reaction ("lobstering"), whereby an alarmed animal rapidly flexes its tail, causing it to dart backwards. Krill can reach speeds of over 60 cm per second by this means. The Induction period, trigger time to optical stimulus (physiology), stimulus is, in spite of the low temperatures, only 55 milliseconds. In th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian Arthropods
The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 486.85 Ma. Most of the continents lay in the southern hemisphere surrounded by the vast Panthalassa, Panthalassa Ocean. The assembly of Gondwana during the Ediacaran and early Cambrian led to the development of new Convergent boundary, convergent plate boundaries and Volcanic arc, continental-margin arc magmatism along its margins that helped drive up global temperatures. Laurentia lay across the equator, separated from Gondwana by the opening Iapetus Ocean. The Cambrian marked a profound change in Life, life on Earth; prior to the Period, the majority of living organisms were small, Unicellular organism, unicellular and poorly preserved. Complex, multicellular organisms gradually became more common during the Ediacaran, but it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enigmatic Arthropod Taxa
Enigmatic is an adjective meaning "mysterious" or "puzzling". It may also refer to: * ''Enigmatic'' (album), a 1970 album by Czesław Niemen * '' Enigmatic: Calling'', a 2005 album by Norwegian progressive metal band Pagan's Mind * Enigmatic scale, musical scale used by Verdi and others * "The Enigmatic", a song by Joe Satriani on the album '' Not of This Earth'' See also * Enigmatic leaf turtle, a species of Asian leaf turtle * Enigmatic moray eel, a species found in the Pacific and Indian Oceans * ''Glaresis ''Glaresis'' is a genus of beetles, sometimes called "Enigmatic scarab beetles", in its own family, Glaresidae. It is closely related to, and was formerly included in, the family Scarabaeidae. Although its members occur in arid and sandy areas wo ...'', a genus of beetles sometimes called "enigmatic scarab beetles" * Enigma (other) {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
