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Liwiidae
Liwiidae is a family of arthropods in the order Nektaspida. Members are known from the Cambrian and 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. T ... periods. Taxonomy *'' Liwia'' Dzik and Lendzion, 1988 :*'' Liwia plana'' Lendzion, 1975 :*'' Liwia convexa'' Lendzion, 1975 *'' Soomaspis'' Fortey & Theron, 1995 :*'' Soomaspis splendida'' Fortey & Theron, 1995 *'' Tariccoia'' Hammann ''et al.'', 1990 :*'' Tariccoia arrusensis'' Hammann ''et al.'', 1990 References Nektaspida Prehistoric arthropod families Cambrian first appearances Ordovician first appearances {{nektaspida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tariccoia Arrusensis
''Tariccoia'' is a genus of nektaspid arthropods belonging to the family Liwiidae, known from fossils found in Ordovician strata in Sardinia and Morocco. It is between and long. It has a headshield (or cephalon) wider than the tailshield (pygidium), and in between them three (or four?) thoracic body segments (somites). Etymology The name of the genus references the Sardinian paleontologist M. Taricco. The species was named after the Riu is Arrus Member, the deposit in which it was found. Description ''Tariccoia arrusensis'' is between 2.5 and 6 cm along the axis, almost half a wide as long. The dorsal exoskeleton consists of a cephalon, a pygidium and two or three thoracic somites with articulating half-rings, all non-calcified. The cephalon is sub-semicircular, widest near the rounded genal angles. The cephalon is wider than the pygidium. Eyes are absent. Antennas are not known. The body is constricted at the two or three thoracic somites, so the animal gives the im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nektaspida
Nektaspida (also called Naraoiida, Nektaspia and Nectaspida) is an extinct order of non- mineralised artiopodan arthropods. They are known from the mid-Cambrian to the upper Silurian. Originally classified as trilobites, which they superficially resemble, they are now placed as close relatives as members of the Trilobitomorpha within Artiopoda. The order is divided into three major families; Emucarididae, Liwiidae, and Naraoiidae. Naming history and taxonomic placement The order was originally proposed by Raymond in 1920 as Nektaspia. Størmer corrected it to Nectaspida for the 1959 ''Treatise on Invertebrate Paleontology'' to conform with the names of the other trilobite orders. Whittington described it in 1985 with the spelling Nektaspida; the revised 1997 Treatise by Raymond and Fortey uses this spelling, as do other modern works. Whittington (1985) placed the order in the Trilobita. Cotton & Braddy (2000) place it in a new "Trilobite clade" containing the Trilobita, recogni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soomaspis
''Soomaspis'' is a genus of small to average size (about 3 cm or 1.2-inch long) marine arthropods in the Liwiidae Family, that lived during the late Ordovician (early Hirnantian). Fossil remains of ''Soomaspis'' were collected from the Soom Shale Lagerstätte in Western Cape, South Africa. ''Soomaspis'' looks like a large, soft agnostid trilobite. It has a headshield (or cephalon) wider than the tailshield (pygidium), and in between them three thoracic body segments (somites). The genus is monotypic, its sole species being ''Soomaspis splendida''. Etymology The name of the genus is a compound word of the deposit where the species was collected (the Soom Shale), and the Greek word ''"aspis"'' (shield). The species epithet, ''splendida'' comes from the Latin word ''"splendere"'' (brightness). Description ''Soomaspis splendida'' is estimated to be over 3 cm (1.2 inches) along the axis,L. Ramskold, J.-Y. Chen, G.D. Edgecombe, and G.-Q. Zhou (1996). "Preservational fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soomaspis Splendida
''Soomaspis'' is a genus of small to average size (about 3 cm or 1.2-inch long) marine arthropods in the Liwiidae Family, that lived during the late Ordovician (early Hirnantian). Fossil remains of ''Soomaspis'' were collected from the Soom Shale Lagerstätte in Western Cape, South Africa. ''Soomaspis'' looks like a large, soft agnostid trilobite. It has a headshield (or cephalon) wider than the tailshield (pygidium), and in between them three thoracic body segments (somites). The genus is monotypic, its sole species being ''Soomaspis splendida''. Etymology The name of the genus is a compound word of the deposit where the species was collected (the Soom Shale), and the Greek word ''"aspis"'' (shield). The species epithet, ''splendida'' comes from the Latin word ''"splendere"'' (brightness). Description ''Soomaspis splendida'' is estimated to be over 3 cm (1.2 inches) along the axis,L. Ramskold, J.-Y. Chen, G.D. Edgecombe, and G.-Q. Zhou (1996). "Preservational fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tariccoia
''Tariccoia'' is a genus of nektaspid arthropods belonging to the family Liwiidae, known from fossils found in Ordovician strata in Sardinia and Morocco. It is between and long. It has a headshield (or cephalon) wider than the tailshield (pygidium), and in between them three (or four?) thoracic body segments (somites). Etymology The name of the genus references the Sardinian paleontologist M. Taricco. The species was named after the Riu is Arrus Member, the deposit in which it was found. Description ''Tariccoia arrusensis'' is between 2.5 and 6 cm along the axis, almost half a wide as long. The dorsal exoskeleton consists of a cephalon, a pygidium and two or three thoracic somites with articulating half-rings, all non-calcified. The cephalon is sub-semicircular, widest near the rounded genal angles. The cephalon is wider than the pygidium. Eyes are absent. Antennas are not known. The body is constricted at the two or three thoracic somites, so the animal gives the im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arthropod cuticle, cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an exoskeleton, external skeleton. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. Some species have wings. They are an extremely diverse group, with up to 10 million species. The haemocoel, an arthropod's internal cavity, through which its haemolymph – analogue of blood – circulates, accommodates its interior Organ (anatomy), organs; it has an open circulatory system. Like their exteriors, the internal or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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 Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), 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 Celtic Britons, 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 (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, 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 Union of Geological Sciences, Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liwia
''Liwia'' is a genus of nektaspid, a soft-bodied stem-group chelicerate. It includes the following species, both are known from borehole samples several kilometers in depth from the Zawiszyn Formation in Poland, which has also yielded ''Peytoia infercambriensis ''Peytoia infercambriensis'' is a species of hurdiid radiodont in the genus ''Peytoia''. ''P. infercambriensis'' is the geologically oldest known radiodont; its remains date to the third age of the Cambrian. The type and only known specimen, ....'' *''Liwia plana'' Lendzion, 1975 *''Liwia convexa'' Lendzion 1975 References Nektaspida Fossils of Poland {{nektaspida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liwia Plana
''Liwia'' is a genus of nektaspid, a soft-bodied stem-group chelicerate. It includes the following species, both are known from borehole samples several kilometers in depth from the Zawiszyn Formation in Poland, which has also yielded ''Peytoia infercambriensis ''Peytoia infercambriensis'' is a species of hurdiid radiodont in the genus ''Peytoia''. ''P. infercambriensis'' is the geologically oldest known radiodont; its remains date to the third age of the Cambrian. The type and only known specimen, ....'' *''Liwia plana'' Lendzion, 1975 *''Liwia convexa'' Lendzion 1975 References Nektaspida Fossils of Poland {{nektaspida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liwia Convexa
''Liwia'' is a genus of nektaspid, a soft-bodied stem-group chelicerate. It includes the following species, both are known from borehole samples several kilometers in depth from the Zawiszyn Formation in Poland, which has also yielded ''Peytoia infercambriensis ''Peytoia infercambriensis'' is a species of hurdiid radiodont in the genus ''Peytoia''. ''P. infercambriensis'' is the geologically oldest known radiodont; its remains date to the third age of the Cambrian. The type and only known specimen, ....'' *''Liwia plana'' Lendzion, 1975 *''Liwia convexa'' Lendzion 1975 References Nektaspida Fossils of Poland {{nektaspida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Arthropod Families
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
