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Paleoscolecids
The palaeoscolecids are a group of extinct ecdysozoan worms resembling armoured priapulids. They are known from the Lower Cambrian to the lower Ludfordian (late Silurian); they are mainly found as disarticulated sclerites, but are also preserved in many of the Cambrian lagerstätten. They take their name from the typifying genus ''Palaeoscolex''. Other genera include ''Cricocosmia'' from the Lower Cambrian Chengjiang biota. Their taxonomic affinities within Ecdysozoa have been the subject of debate. Morphology Palaeoscolecids bear an annulated trunk ornamented with circular patterns of phosphatic tesselating plates; a layered cuticle; and an armoured proboscis. They are long and narrow, and can reach tens of centimetres in length. Their cuticle is annulated, typically in complete rings, but sometimes the rings split or only encircle part of the trunk. Each annulus is essentially identical to its neighbours; the only trunk differentiation is at the anterior and posterior. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeoscolecid
The palaeoscolecids are a group of extinct ecdysozoan worms resembling armoured priapulids. They are known from the Lower Cambrian to the lower Ludfordian (late Silurian); they are mainly found as disarticulated sclerites, but are also preserved in many of the Cambrian lagerstätten. They take their name from the typifying genus '' Palaeoscolex''. Other genera include '' Cricocosmia'' from the Lower Cambrian Chengjiang biota. Their taxonomic affinities within Ecdysozoa have been the subject of debate. Morphology Palaeoscolecids bear an annulated trunk ornamented with circular patterns of phosphatic tesselating plates; a layered cuticle; and an armoured proboscis. They are long and narrow, and can reach tens of centimetres in length. Their cuticle is annulated, typically in complete rings, but sometimes the rings split or only encircle part of the trunk. Each annulus is essentially identical to its neighbours; the only trunk differentiation is at the anterior and posterior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalazoscolecidae
''Chalazoscolex'' is a genus of palaeoscolecidian worm known from the Sirius Passet Sirius Passet is a Cambrian Lagerstätte in Peary Land, Greenland. The Sirius Passet Lagerstätte was named after the Slædepatruljen Sirius, Sirius sledge patrol that operates in North Greenland. It comprises six places in Nansen Land, on the eas .... It had around 140 segments, each adorned with two rows of palaeoscolecid plates. Its body was organised into three transverse sections, the medial bearing three large sclerites acrosswise, the laterals bearing ridges. References Cambrian invertebrates Monotypic prehistoric protostome genera Fossil taxa described in 2010 Paleoscolecids {{cambrian-animal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scathascolex
''Scathascolex'' is a genus of palaeoscolecid worm known from the middle Cambrian Burgess Shale. It is the only taxon in that famous locality to exhibit the phosphatic plates that characterize palaeoscolecids, and has certain unusual characteristics – it does not have the multiple sizes of tessellating plates more typical of palaeoscolecids, and has more tail hooks than is the norm. Nevertheless, it is clearly a close relative of ''Palaeoscolex'' and '' Wronascolex''. As with the co-occurring Burgess Shale worm '' Ancalagon'', its name is derived from one of J. R. R. Tolkien John Ronald Reuel Tolkien (, 3 January 1892 – 2 September 1973) was an English writer and philologist. He was the author of the high fantasy works ''The Hobbit'' and ''The Lord of the Rings''. From 1925 to 1945, Tolkien was the Rawlinson ...'s fictional dragons, in this case Scatha. References Prehistoric protostome genera Burgess Shale fossils Paleoscolecids {{Cambrian-animal-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arrakiscolex
''Arrakiscolex'' is a genus of Cambrian palaeoscolecid, the first known from the Marjum Formation in Utah; some specimens from the Weeks Formation could be tentatively assigned to this genus. The holotype has a width of and a length of . The only species is ''Arrakiscolex aasei''. The genus name is inspired by the fictional planet of Arrakis in Frank Herbert novel ''Dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, flat ...'', inhabited by giant sandworms. ''Arrakiscolex'' is distinguished by small, discoid plates distributed over the surface of the preserved cuticle fragments. The plates are smooth with a well-differentiated marginal rim, differentiating them from other genera with larger or differently shaped plates. References Cambrian invertebrates Monotypic prehistoric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cricocosmia
''Cricocosmia'' is an abundant palaeoscolecid worm endemic to the Early Cambrian Chengjiang Biota of Yunnan, China. It resembles modern priapulids, and holds a pivotal role in understanding the evolution of early ecdysozoans. It possessed paired lateral sclerites and paired ventral projections which have been compared with early panarthropod legs. It was a detritivore, living in shallow horizontal burrows, sometimes in great concentration. Description ''Cricocosmia'' specimens are easily identified by two rows of small dorso-lateral sclerites. There were a single pair of sclerites for every annulus of the trunk, beginning a short distance from the smooth introvert. These sclerite rows were bilaterally symmetrical, and consisted of a round base with a surrounding marginal rim, and a thorn-like spine projecting outwards and posteriorly. The first sclerite pair of the trunk were smaller than the succeeding pair - following this, the sclerites follow a pattern of becoming smal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeoscolex
''Palaeoscolex'' is the type genus of the Palaeoscolecid worms, and served as a wastebasket taxon. until its taxonomy was revised and many of its taxa assigned to '' Wronascolex''. The type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ... and only unequivocal species is ''P. piscatorum'', known from mid-trunk segments.Conway Morris S. 1997. The cuticular structure of the 495-Myr-old type species of the fossil worm ~Palaeoscolex~, ~P. piscatorum~ (?Priapulida). Zool. J. Linn. Soc. 119:69–82. References Prehistoric protostome genera Paleoscolecids {{paleo-protostome-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalazoscolex
''Chalazoscolex'' is a genus of palaeoscolecidian worm known from the Sirius Passet Sirius Passet is a Cambrian Lagerstätte in Peary Land, Greenland. The Sirius Passet Lagerstätte was named after the Slædepatruljen Sirius, Sirius sledge patrol that operates in North Greenland. It comprises six places in Nansen Land, on the eas .... It had around 140 segments, each adorned with two rows of palaeoscolecid plates. Its body was organised into three transverse sections, the medial bearing three large sclerites acrosswise, the laterals bearing ridges. References Cambrian invertebrates Monotypic prehistoric protostome genera Fossil taxa described in 2010 Paleoscolecids {{cambrian-animal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xystoscolex
''Xystoscolex'' is a genus of palaeoscolecidian worm known from the Sirius Passet, North Greenland The Northern Inspectorate of Greenland (), also known as North Greenland, was a Danish inspectorate on Greenland consisting of the trading centers and missionary stations along the northwest coast of the island. History West Greenland was di .... References Prehistoric protostome genera Sirius Passet fossils Paleoscolecids {{cambrian-animal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maotianshania
''Maotianshania cylindrica'' is an extinct worm-like creature of average size (up to long and wide). It occurs in the Lower Cambrian (Atdabanian) Chengjiang biota of Northeastern Yunnan, China. It is usually preserved as pink impression. The gut is a dark central zone. The anterior pharnyx and "collar", carry tiny sepia-colored teeth. The very back-end of the body has two small hooks. Etymology ''Maotianshania'' has been named for the Maotianshan shales, home to the famous Chengjiang Lagerstätte. Description The body of ''Maotianshania'' is worm-like, up to 4 cm in length and 2 mm wide, having 3-4 rings (or annuli) per mm. Like its relatives '' Cricocosmia'' and '' Palaeoscolex'', it is usually preserved as a very thin pink impression on the buff-colored matrix that is characteristic for the Maotianshan shales The Maotianshan Shales () are a series of Early Cambrian sedimentary deposits in the Chiungchussu Formation or Heilinpu Formation, famous for thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sirius Passet
Sirius Passet is a Cambrian Lagerstätte in Peary Land, Greenland. The Sirius Passet Lagerstätte was named after the Slædepatruljen Sirius, Sirius sledge patrol that operates in North Greenland. It comprises six places in Nansen Land, on the east shore of J.P. Koch Fjord in the far north of Greenland. It was discovered in 1984 by A. Higgins of the Geological Survey of Denmark and Greenland, Geological Survey of Greenland. A preliminary account was published by Simon Conway Morris and others in 1987 and expeditions led by J. S. Peel and Conway Morris have returned to the site several times between 1989 and the present. A field collection of perhaps 10,000 fossil specimens has been amassed. It is a part of the Buen Formation. Age The fauna is inevitably compared to that of the Burgess Shale, although it is probably ten to fifteen million years older – vs. ) – and more closely contemporaneous with the fauna of the Maotianshan shales from Chengjiang, which are dated to . Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microdictyon
is an extinct genus of lobopodian worm characterized by its net-like sclerite armour plates, known from Cambrian deposits around the world. Soft-bodied fossils which preserve more than the sclerites are only known from the Chengjiang Lagerstätte of Yunnan, China. History ''Microdictyon'' sclerite plates have been recovered from around the globe, recovered from rock via acid dissolution which eats away at the rock but leaves behind compositionally distinct microfossils. The first of them were found in the '' Strenuella'' Limestone of Comley, England, in 1975. The genus ''Microdictyon'' was erected by Stefan Bengston, Vladimir Missarzhevsky, and S. C. Matthews in 1981, as an enigmatic net-like microfossil, based on a few isolated plates from South Kazakhstan, although this description lacked a type species and proper description, so a following publication by the same authors in 1986 corrected this. It was unknown at the time what animal could have produced it - suggestio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
