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Radiodonts
Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. They may be referred to as radiodonts, radiodontans, radiodontids, anomalocarids, or anomalocaridids, although the last two originally refer to the family Anomalocarididae, which previously included all species of this order but is now restricted to only a few species. Radiodonts are distinguished by their distinctive frontal appendages, which are morphologically diverse and used for a variety of functions. Radiodonts included the earliest large predators known, but they also included sediment sifters and filter feeders. Some of the most famous species of radiodonts are the Cambrian taxa '' Anomalocaris canadensis'', '' Hurdia victoria'', ''Peytoia nathorsti'', '' Titanokorys gainessii, Cambroraster falcatus'' and '' Amplectobelua symbrachiata'', the Ordovician '' Aegirocassis benmoulai'' and the Devonian '' Schinderhannes bartelsi''. Etymology The name Radiodonta (Lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanokorys Gainesii
''Titanokorys'' is a genus of extinct hurdiid radiodont (a grouping of primitive stem arthropods which lived during the early Paleozoic) that existed during the mid Cambrian. It is the largest member of its family from the Cambrian, with a body length of long, making it one of the largest animals of the time. It bears a resemblance to the related genus '' Cambroraster''. Fossils of ''T. gainesi'' were first found within Marble Canyon in 2018. The fossils were not named until 2021 because they were assumed to be giant specimens of ''Cambroraster''. The creature was one of several genera of radiodonts known from the Burgess Shale, with some of the others being ''Cambroraster'', ''Anomalocaris'', ''Peytoia'', and ''Hurdia''. ''Titanokorys'' is distinguished from other Burgess Shale radiodonts because of its large anterior sclerite (head covering carapace) and a pair of spines on the anteroventral sides. Based on the shape of its appendages, ''Titanokorys'' is speculated to have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schinderhannes (genus)
''Schinderhannes bartelsi'' is a species of hurdiid radiodont (anomalocaridid) known from one specimen from the lower Devonian Hunsrück Slates. Its discovery was astonishing because previously, radiodonts were known only from exceptionally well-preserved fossil beds (Lagerstätten) from the Cambrian, 100 million years earlier. Discovery The single specimen was discovered in the Eschenbach-Bocksberg Quarry in Bundenbach, and is named after the outlaw Schinderhannes who frequented the area. Its specific epithet ''bartelsi'' honours Christoph Bartels, a Hunsrück Slate expert. The specimen is now housed in the Naturhistorisches Museum, Mainz. Morphology ''Schinderhannes'' is about long in full body length (6.8cm long excluding telson). Like other radiodonts, the head bears a pair of spiny frontal appendages, a radially-arranged ventral mouthpart ( oral cone), and a pair of large lateral compound eyes. Detailed morphology of the frontal appendages and oral cone are equivoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomalocaris
''Anomalocaris'' ("unlike other shrimp", or "abnormal shrimp") is an extinct genus of radiodont, an order of early-diverging stem-group arthropods. The first fossils of ''Anomalocaris'' were discovered in the ''Ogygopsis'' Shale of the Stephen Formation in British Columbia, Canada by Joseph Frederick Whiteaves, with more examples found by Charles Doolittle Walcott in the Burgess Shale unit of the Stephen Formation. Other closely related fossils have been found in the older Emu Bay Shale of Australia, as well as possibly elsewhere. Originally several fossilized parts discovered separately (the mouth, frontal appendages and trunk) were thought to be three separate creatures, a misapprehension corrected by Harry B. Whittington and Derek Briggs in a 1985 journal article. With a body length close to 40 centimetres, ''A. canadensis'' is thought to be one of the earliest examples of an apex predator, though others have been found in older Cambrian lagerstätten deposits. Discovery ''An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tamisiocarididae
Tamisiocarididae is a family of radiodonts, extinct marine animals related to arthropods, that bore finely-spined appendages that were presumably used in filter-feeding. When first discovered, the clade was named Cetiocaridae after a speculative evolution artwork, ''Bearded Ceticaris'' by John Meszaros, that depicted a hypothetical filter-feeding radiodont at a time before any were known to exist. However, the family name was not valid according to the International Code of Zoological Nomenclature, as no real genus named "Cetiocaris" exists, and in 2019 it was formally replaced by the name Tamisiocarididae, after the only valid genus of the clade at the time. The family is only known from Series 2 of the Cambrian, unlike other radiodont families, which persisted longer into the Cambrian. All known species would have lived in tropical or subtropical waters, suggesting a preference for warmer waters. Description Like most radiodonts, cetiocarids have spiny frontal appendages. Howev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Houcaris
''Houcaris'' is a genus of tamisiocarididid radiodonts known from Cambrian Series 2 of China and the United States. It contains two species, ''Houcaris saron'' and ''Houcaris magnabasis'', both of which were originally named as species of the related genus ''Anomalocaris''. The genus ''Houcaris'' was established for the two species in 2021 and honors Hou Xianguang, who had discovered and named the type species ''H. saron'' in 1995 along with his colleagues Jan Bergström and Per E. Ahlberg. Species ''Houcaris saron'' ''H. saron'', known from Maotianshan Shale in Yunnan, is first described in 1995 as ''Anomalocaris saron''. This species is only known from frontal appendages. There is a specimen (ELRC 20001) that is previously considered as whole body fossil of this species, but later study shows that this specimen is not belonging to this species, and later given own genus '' Innovatiocaris''. Length of frontal appendage is up to at least 12 cm. Sometimes considered to bel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegirocassis
''Aegirocassis'' is an extinct genus of radiodont arthropod belonging to the family Hurdiidae that lived 480 million years ago during the early Ordovician. It is known by a single species, ''Aegirocassis benmoulai''. Van Roy initiated scientific study of the fossil, the earliest known of a "giant" filter-feeder discovered to date. ''Aegirocassis'' is considered to have evolved from early predatory radiodonts. Description File:20210221 Aegirocassis size.png, Size estimation File:YPM 527123 Aegirocassis benmoulai frontal appendage.png, Fossil of frontal appendage File:20191229 Radiodonta frontal appendage Aegirocassis benmoulai Aegirocassis benmoulae.png, Reconstruction of frontal appendage ''A. benmoulai'' was the largest known radiodont and largest animal existed in this period, and the length was described as exceeding in the scientific journal ''Nature''. The fossil was preserved with exceptional three-dimensional detail, unlike most other radiodont fossils, in which th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hurdiidae
Hurdiidae is an extinct cosmopolitan family of radiodonts, a group of stem-group arthropods, which lived during the Paleozoic Era. It is the most long-lived radiodont clade, lasting from the Cambrian period to the Devonian period. Description Hurdiidae is characterized by frontal appendages with distal region composed of 5 subequal blade-like endites, alongside the enlarged head carapaces and tetraradial mouthpart ( oral cone). The frontal appendages of hurdiids have a distinctive morphology, with the appendage of most species bearing five equally-sized elongate blade-like ventral spines known as endites. Subsequent podomeres were reduced in size and with only small endites or none. Each podomere bore only a single endite, unlike other radiodonts, in which the endites were paired. In most species, the endites were curved medially, so that the appendages formed a basket-like structure. Some hurdiids had greater numbers of endites, with '' Cordaticaris'' bearing seven endi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplectobeluidae
''Amplectobeluidae'' is a clade of Cambrian radiodonts. Definition In 2014, ''Amplectobeluidae'' was defined as the most inclusive clade including '' Amplectobelua symbrachiata'' but not '' Anomalocaris canadensis'', '' Tamisiocaris borealis'', or '' Hurdia victoria''. Description Amplectobeluids could be recognized by frontal appendages with well-developed first distal endite, which forming a pincer-like structure that presumably better suited for a grasping function. Complete body fossils of amplectobeluids are only known by '' Amplectobelua'' and '' Lyrarapax'', both showing combination of characters resembling ''Anomalocaris ''Anomalocaris'' ("unlike other shrimp", or "abnormal shrimp") is an extinct genus of radiodont, an order of early-diverging stem-group arthropods. The first fossils of ''Anomalocaris'' were discovered in the ''Ogygopsis'' Shale of the Stephen Fo ...'' (i.e. streamlined body; small head with ovoid sclerites; well-developed swimming flaps; a pair o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paranomalocaris
''Paranomalocaris'' is a genus of primitive radiodont recovered from Wulongqing Formation, eastern Yunnan. It contains two species, ''Paranomalocaris multisegmentalis'' and ''P. simplex''. It is only known from its frontal appendage (now known to be homologous to the labrum of euarthropod and primary antennae of Onychophorans Onychophora (from grc, ονυχής, , "claws"; and , , "to carry"), commonly known as velvet worms (due to their velvety texture and somewhat wormlike appearance) or more ambiguously as peripatus (after the first described genus, '' Peripatus ...). The frontal appendage features endites with numerous auxiliary spines, and at least 22 segments (podomeres), hence the specific name ''multisegmentalis''. References {{Taxonbar, from=Q65042329 Anomalocaridids Fossil taxa described in 2013 Cambrian arthropods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laminacaris
''Laminacaris'' is a genus of extinct stem-group arthropods (Radiodonta) that lived during the Cambrian period. It is monotypic with a single species ''Laminacaris chimera'', the fossil of which was described from the Chengjian biota of China in 2018. Around the same time, two specimens that were similar or of the same species were discovered at the Kinzers Formation in Pennsylvania, USA. The first specimens from China were three frontal appendages, without the other body parts. ''Laminacaris'' specimens were discovered from three sites in China: the mudstones of the Yu'anshan Member of the Chiungchussu Formation in eastern Yunnan Province, the Mafang section in the Haikou area at Kunming, and the Heimadi section, Chengjiang. The name is derived from Latin words, ''lamina'' meaning thin blade, and ''caris'' for crab; the species name refers to a Greek mythological creature, ''Chimera'', that has a body composed of parts of more than one animal. In 2022, it is treated that is poss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peytoia Nathorsti
''Peytoia'' is a genus of hurdiid radiodont that lived in the Cambrian period, containing two species, ''Peytoia nathorsti'' from the Miaolingian of Canada and '' Peytoia infercambriensis'' from Poland, dating to Cambrian Stage 3. Its two frontal appendages had long bristle-like spines, it had no fan tail, and its short stalked eyes were behind its large head. 108 specimens of ''Peytoia'' are known from the Greater Phyllopod bed, where they comprise 0.21% of the community. ''Peytoia nathorsti'' and its junior synonym ''Laggania cambria'' played a major role in the discovery of the radiodont body plan. Initially interpreted as a jellyfish and a sea cucumber respectively, they were eventually shown to be the mouthparts and body of a single animal, which bore ''Anomalocaris''-like appendages. ''Peytoia infercambriensis'' is the geologically oldest known radiodont species. Classification ''Peytoia'' belongs to the clade Hurdiidae, and is closely related to the contemporary genus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hurdia
''Hurdia'' is an extinct genus of hurdiid radiodont that lived 505 million years ago during the Cambrian Period. As a radiodont like '' Peytoia'' and '' Anomalocaris'', it is part of the ancestral lineage that led to euarthropods. Description ''Hurdia'' was one of the largest organisms in the Cambrian oceans, ''H. victoria'' reached approximately in length, while ''H. triangulata'' reached up to just . Its head bore a pair of rake-like frontal appendages which shovelled food into its pineapple-ring-like mouth (oral cone). Like other hurdiids, ''Hurdia'' bore a large frontal carapace protruding from its head composed of three sclerites: a central component known as the H-element and two lateral components known as P-elements. The function of this organ remains mysterious; it cannot have been protective as there was no underlying soft tissue. Originally, it is estimated that body flaps ran along the sides of the organisms, from which large gills were suspended. However, anato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
