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Pseudoniscidae
Pseudoniscidae is an extinct Family (biology), family of synziphosurine chelicerates that lived in the Silurian. Pseudoniscidae is classified inside the clade Planaterga, alongside Bunodidae and Dekatriata (Chasmataspidida, chasmataspidids, Eurypterid, eurypterids and Arachnid, arachnids). Pseudoniscidae is composed by two genera, ''Cyamocephalus'' and ''Pseudoniscus'' (the type genus). References Synziphosurina Planaterga Silurian first appearances Silurian arthropods Silurian extinctions Prehistoric arthropod families {{Chelicerata-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planaterga
Planaterga is a clade of prosomapod euchelicerates including several synziphosurid genera (mainly bunodids and pseudoniscids) and the group Dekatriata (which in turn includes arachnids, chasmataspidids and eurypterid Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the Order (biology), order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 Myr, million yea ...s). Planaterga is defined by the opisthosoma with tergites broadest at third or fourth and lacking enlarged axial nodes, carapace (prosomal dorsal shield) with reduced genal spines, as well as somite VII (first opisthosomal segment) with reduced appendages and microtergite. References Middle Ordovician first appearances {{Chelicerata-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudoniscus
''Pseudoniscus'' is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. ''Pseudoniscus'' was regarded as part of the clade Planaterga. Fossils of the genus have been discovered in Deposition (geology), deposits of the Silurian Period (geology), period in the United Kingdom, the United States and Estonia. ''Pseudoniscus'' is one of the two members of the Family (biology), family Pseudoniscidae, the other being ''Cyamocephalus''. The prosoma of ''Pseudoniscus'' covered by a carapace with recurved posterior margin and pointed genal spines. Most of the dorsal feature on the carapace (e.g. ophthalmic ridges, cardiac lobe) are not significantly expressed. At least some species have a median spine in front of the carapace like the close-related ''Cyamocephalus''. Unlike most other synziphosurines with opisthosoma subdivided into a wide preabdomen and narrow postabdomen, the 10-segmented opisthosoma of ''Pseudoniscus'' possess undivided, metameric segmentatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bunodidae
Bunodidae is an extinct family of synziphosurine chelicerates that lived in the Silurian. Bunodidae is classified inside the clade Planaterga alongside Pseudoniscidae and Dekatriata ( chasmataspidids, eurypterids and arachnids). Bunodidae is composed by two genera, '' Bunodes'' (the type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal f ...) and '' Limuloides''. References Synziphosurina Planaterga Silurian first appearances Silurian arthropods Silurian extinctions Prehistoric arthropod families {{Chelicerata-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyamocephalus
''Cyamocephalus'' is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. ''Cyamocephalus'' was regarded as part of the clade Planaterga. Fossils of the single and type species, ''C. loganensis'', have been discovered in deposits of the Silurian period in Lesmahagow, Scotland (in the United Kingdom). ''Cyamocephalus'' is one of the two members of the family Pseudoniscidae, the other being ''Pseudoniscus ''Pseudoniscus'' is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. ''Pseudoniscus'' was regarded as part of the clade Planaterga. Fossils of the genus have been discovered in Deposition (geology), deposits of th ...''. ''Cyamocephalus'' differ from ''Pseudoniscus'' by the fused tergites of 6th and 7th opisthosomal segments. References Synziphosurina Planaterga Silurian first appearances Silurian arthropods Fossils of Scotland Fossil taxa described in 1927 {{Chelicerata-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arachnid
Arachnida () is a class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegaroons. Almost all adult arachnids have eight legs, although the front pair of legs in some species has converted to a sensory function, while in other species, different appendages can grow large enough to take on the appearance of extra pairs of legs. The term is derived from the Greek word (''aráchnē'', 'spider'), from the myth of the hubristic human weaver Arachne, who was turned into a spider. Almost all extant arachnids are terrestrial, living mainly on land. However, some inhabit freshwater environments and, with the exception of the pelagic zone, marine environments as well. They comprise over 100,000 named species, of which 47,000 are species of spiders. Morphology Almost all adult arachnids have eight legs, unlike adult inse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silurian Arthropods
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 the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Synziphosurina
Synziphosurina is a paraphyletic group of chelicerate arthropods previously thought to be basal horseshoe crabs (Xiphosura). It was later identified as a grade composed of various basal euchelicerates, eventually excluded form the monophyletic Xiphosura ''sensu stricto'' and only regarded as horseshoe crabs under a broader sense ('Xiphosura' ''sensu lato''). Synziphosurines survived at least since early Ordovician to early Carboniferous in ages, with most species are known from the in-between Silurian strata. File:20200920 Synziphosurina dorsal segmentation.png, Dorsal morphology and variation of opisthosomal segmentation across synziphosurines. While ''Weinbergina'' and ''Willwerathia'' being exceptionally large, most synziphosurines are small arthropods with body length ranging only about a few centimeters long. The body of synziphosurine composed of a prosoma covered by a dome-like carapace (prosomal dorsal shield) and an opisthosoma with usually unfused 9-11 segments expre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural History Museum Bern
The Natural History Museum of Bern (german: Naturhistorisches Museum Bern) is a museum in Bern, Switzerland. In its teaching and research it cooperates closely with the University of Bern.In Bern beliebt - auf der ganzen Welt beachtet It is visited by around 131,000 people yearly. History The museum is owned by the Burgergemeinde of Bern, so it is also known as . It was officially founded in 1832. It is located on Bernastrasse, in the Kirchenfeld , in a building that was erected between 1932 and 1934, opened in 1936 and expanded several times since th ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Genus
In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal family-group taxon is a nominal genus called the 'type genus'; the family-group name is based upon that of the type genus." Any family-group name must have a type genus (and any genus-group name must have a type species, but any species-group name may, but need not, have one or more type specimens). The type genus for a family-group name is also the genus that provided the stem to which was added the ending -idae (for families). :Example: The family name Formicidae has as its type genus the genus ''Formica'' Linnaeus, 1758. Botanical nomenclature In botanical nomenclature, the phrase "type genus" is used, unofficially, as a term of convenience. In the '' ICN'' this phrase has no status. The code uses type specimens for ranks up to fam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus '' Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should clearly demons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chasmataspidida
Chasmataspidids, sometime referred to as chasmataspids, are a group of extinct chelicerate arthropods that form the order Chasmataspidida. Chasmataspidids are probably related to horseshoe crabs (Xiphosura) and/or sea scorpions (Eurypterida), with more recent studies suggest that they form a clade (Dekatriata) with Eurypterida and Arachnida. Chasmataspidids are known sporadically in the fossil record through to the mid- Devonian, with possible evidence suggesting that they were also present during the late Cambrian. Chasmataspidids are most easily recognised by having an opisthosoma divided into a wide forepart (preabdomen) and a narrow hindpart (postabdomen) each comprising 4 and 9 segments respectively. There is some debate about whether they form a natural (i.e. monophyletic) group. Distribution Chasmataspidids survived at least since Ordovician to mid- Devonian in age. As of 2019, most chasmataspidids (with a total of 9 species) are known from the Devonian strata, while ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
