Acaste (genus)
''Acaste'' is a genus of extinct trilobite of the order Phacopida which lived throughout the Silurian period (Wenlock Group). Though many species had been included, it now has only one species, ''Acaste downingiae.'' It is characterized by a convex dorsal surface, an absence of spines, a shortening of the head-shield and a general rounding off of all angles.H H Swinnerton - ''Outlines of Palaentology'', Edward Arnold (Publishers) Ltd, 1972 (p. 247) . Etymology * ''A. lokii'' is named after Loki, the Norse god of mischief. Loki tricked the blind god Höðr to kill the god of beauty Baldr, and so started the demise of the world (or Ragnarök). This epithet was chosen by Edgecombe because it is based on the cephalon of ''A. longisulcata'', which has turned out to be a mixed collection. The pygidium of ''A. longisulcata'' belongs to a Phacopoidea Phacopoidea is a superfamily of trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the c ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Silurian
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods (myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone during ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Baldr
Baldr (also Balder, Baldur) is a god in Germanic mythology. In Norse mythology, Baldr (Old Norse: ) is a son of the god Odin and the goddess Frigg, and has numerous brothers, such as Thor and Váli. In wider Germanic mythology, the god was known in Old English as , and in Old High German as , all ultimately stemming from the Proto-Germanic theonym ('hero' or 'prince'). During the 12th century, Danish accounts by Saxo Grammaticus and other Danish Latin chroniclers recorded a euhemerized account of his story. Compiled in Iceland during the 13th century, but based on older Old Norse poetry, the ''Poetic Edda'' and the ''Prose Edda'' contain numerous references to the death of Baldr as both a great tragedy to the Æsir and a harbinger of Ragnarök. According to ''Gylfaginning'', a book of Snorri Sturluson's Prose Edda, Baldr's wife is Nanna and their son is Forseti. Baldr had the greatest ship ever built, Hringhorni, and there is no place more beautiful than his hall, Breidablik ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Silurian First Appearances
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods (myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone during th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Trilobites Of Oceania
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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Trilobites Of Africa
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 st ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Silurian Trilobites
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods (myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone durin ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Phacopida Genera
Phacopida ("lens-face") is an order of trilobites that lived from the Late Cambrian to the Late Devonian. It is made up of a morphologically diverse assemblage of taxa in three related suborders. Characteristics Phacopida had 8 to 19 thoracic segments and are distinguishable by the expanded glabella, short or absent preglabellar area, and schizochroal (Phacopina) or holochroal (Cheirurina and Calymenina) eyes. Schizochroal eyes are compound eyes with up to around 700 separate lenses. Each lens has an individual cornea which extended into a rather large sclera. The development of schizochroal eyes in phacopid trilobites is an example of post-displacement paedomorphosis. The eyes of immature holochroal Cambrian trilobites were basically miniature schizochroal eyes. In Phacopida, these were retained, via delayed growth of these immature structures (post-displacement), into the adult form. ''Eldredgeops rana'' (Phacopidae) and ''Dalmanites limulurus'' (Dalmanitidae) are two of ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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List Of Trilobites
This list of trilobites is a comprehensive listing of all genera that have ever been included in the Arthropod class Trilobita, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful ('), or were not formally published ('), as well as junior synonyms of more established names, and genera that are no longer considered trilobites. A Aa *''Aayemenaytcheia'' Ab *'' Abadiella'' (=''Parabadiella''; =''Danagouia'') *'' Abakania'' *'' Abakanopleura'' *'' Abakolia'' (=''Costadiscus'') *'' Abdulinaspis'' *'' Abharella'' Ac *'' Acadolenus'' *''Acadoparadoxides'' (=''Entomolithus''; =''Entomostracites''; =''Eoparadoxides'') *'' Acanthalomina'' *'' Acanthocephalus'' (=''Alomataspis'') *'' Acanthometopus'' *'' Acanthomicmacca'' (=''Chengkouia''; =''Jaskovitchella''; =''Myopsomicmacca'') *'' Acanthoparypha'' *'' Acanthophillipsia'' *'' Acanthopleurella'' *'' Acanthopyge'' (=''Euarges'') *'' Acastava'' *' ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Acastoides
''Acastoides'' is an extinct genus of trilobite that lived during the Silurian and Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe .... It has been found in Bolivia, France, Morocco, Poland, Turkey and the United Kingdom. Distribution * ''A. constricta'' is found in the Silurian of the United Kingdom (Wenlock, Woolhope Shale, Worcestershire, Malvern). Taxonomy Species previously assigned to ''Acastoides'' * ''A. verneuili'' = ''Calmonia terrarocenai'' See also * List of trilobites References External links Photos of ''Acastoides sp.''''Acastoides''at the Paleobiology Database Acastidae Prehistoric life of Europe Devonian trilobites Wenlock first appearances Eifelian extinctions Silurian trilobites of Europe {{devonian-animal-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Synonym (taxonomy)
The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnaeus was the first to give a scientific name (under the currently used system of scientific nomenclature) to the Norway spruce, which he called ''Pinus abies''. This name is no longer in use, so it is now a synonym of the current scientific name, ''Picea abies''. * In zoology, moving a species from one genus to another results in a different binomen, but the name is considered an alternative combination rather than a synonym. The concept of synonymy in zoology is reserved for two names at the same rank that refers to a taxon at that rank - for example, the name ''Papilio prorsa'' Linnaeus, 1758 is a junior synonym of ''Papilio levana'' Linnaeus, 1758, being names for different seasonal forms of the species now referred to as ''Araschnia le ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Treatise On Invertebrate Paleontology
The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and covering every phylum, class, order, family, and genus of fossil and extant (still living) invertebrate animals. The prehistoric invertebrates are described as to their taxonomy, morphology, paleoecology, stratigraphic and paleogeographic range. However, taxa with no fossil record whatsoever have just a very brief listing. Publication of the decades-long ''Treatise on Invertebrate Paleontology'' is a work-in-progress; and therefore it is not yet complete: For example, there is no volume yet published regarding the post-Paleozoic era caenogastropods (a molluscan group including the whelk and Common periwinkle, periwinkle). Furthermore, every so often, previously published volumes of the ''Treatise'' are revised. Evolution of the proje ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Phacopoidea
Phacopoidea is a superfamily of 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 At ...s. External linkstrilobites.info- Gallery of Phacopida - General information- More images Arthropod superfamilies Phacopina {{Phacopida-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |