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Skeemella
''Skeemella'' is a genus of elongate animal from the Middle Cambrian Wheeler Shale and Marjum lagerstätte of Utah. It has been classified with the banffozoan vetulicolians. Description ''Skeemella'', which was first described in 2005, is diagnosed as having a body in two sections, covered in cuticle. The anterior section is short and wide, has a straight dorsal margin and a curving ventral margin, and is divided longitudinally in a way that makes it resemble a head shield. The anterior region is interpreted as being made of nine segments separated by thinner membranes (rather than as a single unit with multiple openings). ''Skeemella'' has a narrow, worm-shaped rear section with 43 segments in holotype specimen, identified as tergites separated by flexible membranes. The rear section terminates in what appears to be an arthropod telson, an elongate, unsegmented flattened structure that ends in two backward-pointing spines. In 2020, two more specimens of ''S. clavula'' were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Banffozoan
Banffozoa (also called Heteromorphida) is an extinct class of bilaterians. Most workers place it in the Vetulicolia, but the protostome-like features of some members have motivated ongoing debate. Banffozoa consists of the order Banffiata (which has only one family, Banffiidae) as well as a dwarf "Form A" that has not been formally described or named. ''Skeemella'' has been placed ''incertae sedis'' in this class, but has more recently been placed with the Banffiidae (if it is a banffozoan or vetulicolian at all). Banffozoa may be paraphyletic even if Vetulicolia is monophyletic. Description Banffozoans have a bipartite body with a smooth anterior part that generally lacks evidence of segmentation and may or may not have a lateral groove. The posterior section features far more segments than the Vetulicolida, and (except in ''Skeemella'') these segments are each much narrower as well. Lateral pouches such as those found in the Vetulicolida have not been seen, although some q ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vetulicolians
Vetulicolia is a group of bilaterian marine animals encompassing several extinct species from the Cambrian, and possibly Ediacaran, periods. As of 2023, the majority of workers favor placing Vetulicolians in the stem group of the Chordata, but some continue to favor a more crownward placement as a sister group to the Tunicata. It was initially erected as a monophyletic clade with the rank of phylum in 2001, with subsequent work supporting its monophyly. However, more recent research suggests that vetulicolians may be paraphyletic and form a basal evolutionary grade of stem chordates. Etymology The taxon name, Vetulicolia, is derived from the type genus, ''Vetulicola'', which is a compound Latin word composed of ''vetuli'' "old" and ''cola'' "inhabitant". It was named after ''Vetulicola cuneata'', the first species of the group described in 1987. Description The vetulicolian body plan comprises two parts: a voluminous rostral (anterior) forebody, tipped with an anteriorly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marjum Formation
The Marjum Formation is a Cambrian geological formation that overlies the Wheeler Shale in the House Range, Utah. It is named after its type locality, Marjum Pass, and was defined in 1908. The formation is known for its occasional preservation of soft-bodied tissue, and is slightly younger than the Burgess Shale, falling in the ''Ptychagnostus praecurrens'' trilobite zone. Fossil content Ambulacrarians Arthropods Chancelloriids Chordates Cnidarians Moon, Caron & Moysiuk (2023) considered these fossils would be ctenophores instead. Ctenophores Lophotrochozoans Scalidophorans Sponges See also * List of fossiliferous stratigraphic units in Utah * Paleontology in Utah References {{reflist Cambrian geology of Utah Cambrian southern paleotropical deposits Limestone formations of the United States Shale formations of the United States ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheeler Shale
The Wheeler Shale (named by Charles Walcott) is a Cambrian ( 507 Ma) fossil locality world-famous for prolific agnostid and ''Elrathia kingii'' trilobite remains (even though many areas are barren of fossils) and represents a Konzentrat-Lagerstätte. Varied soft bodied organisms are locally preserved, a fauna (including ''Naraoia'', ''Wiwaxia'' and ''Hallucigenia'') and preservation style ( carbonaceous film) normally associated with the more famous Burgess Shale. As such, the Wheeler Shale also represents a Konservat-Lagerstätten. Together with the Marjum Formation and lower Weeks Formation, the Wheeler Shale forms of limestone and shale exposed in one of the thickest, most fossiliferous and best exposed sequences of Middle Cambrian rocks in North America. At the type locality of Wheeler Amphitheater, House Range, Millard County, western Utah, the Wheeler Shale consists of a heterogeneous succession of highly calcareous shale, shaley limestone, mudstone and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Cambrian
Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (other) * Middle Brook (other) * Middle Creek (other) * Middle Island (other) * Middle Lake (other) * Middle Mountain, California * Middle Peninsula, Chesapeake Bay, Virginia * Middle Range, a former name of the Xueshan Range on Taiwan Island * Middle River (other) * Middle Rocks, two rocks at the eastern opening of the Straits of Singapore * Middle Sound, a bay in North Carolina * Middle Township (other) * Middle East Music *Middle (song), "Middle" (song), 2015 *The Middle (Jimmy Eat World song), "The Middle" (Jimmy Eat World song), 2001 *The Middle (Zedd, Maren Morris and Grey song), "The Middle" (Zedd, Maren Morris and Grey song), 2018 *"Middle", a song by Rocket from the Crypt from their 1995 album ''Scream, Dracula, Scream!'' *"The Middle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derek Briggs
Derek Ernest Gilmor Briggs (born 10 January 1950) is an Irish palaeontologist and taphonomist based at Yale University. Briggs is one of three palaeontologists, along with Harry Blackmore Whittington and Simon Conway Morris, who were key in the reinterpretation of the fossils of the Burgess Shale. He is the Yale University G. Evelyn Hutchinson Professor of Geology and Geophysics, Curator of Invertebrate Paleontology at Yale's Peabody Museum of Natural History, and former Director of the Peabody Museum. Education Briggs was educated at Trinity College Dublin where he graduated with a Bachelor of Arts degree in Geology in 1972. He went on to the University of Cambridge to work under British palaeontologist Harry Blackmore Whittington. He was awarded a PhD in 1976 on ''Arthropods from the Burgess Shale, Middle Cambrian, Canada''. Research and career While at the University of Cambridge, Briggs worked on the fossils of the Middle Cambrian Burgess Shale of British Columbia alon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagerstätte
A Fossil-Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that preserves an exceptionally high amount of palaeontological information. ''Konzentrat-Lagerstätten'' preserve a high concentration of fossils, while ''Konservat-Lagerstätten'' offer exceptional fossil preservation, sometimes including preserved soft tissues. ''Konservat-Lagerstätten'' may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus delaying the decomposition of both gross and fine biological features until long after a durable impression was created in the surrounding matrix. ''Fossil-Lagerstätten'' spans geological time from the Neoproterozoic era to the present. Worldwide, some of the best examples of near-perfect fossilization are the Cambrian Maotianshan shales and Burgess Shale, the Ordovician Soom Shale, the Silurian Waukesha Biota, the Devonian Hunsrück Slates and Gogo Formation, the Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utah
Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northeast, Idaho to the north, and Nevada to the west. In comparison to all the U.S. states and territories, Utah, with a population of just over three million, is the List of U.S. states and territories by area, 13th largest by area, the List of U.S. states and territories by population, 30th most populous, and the List of U.S. states by population density, 11th least densely populated. Urban development is mostly concentrated in two regions: the Wasatch Front in the north-central part of the state, which includes the state capital, Salt Lake City, and is home to roughly two-thirds of the population; and Washington County, Utah, Washington County in the southwest, which has approximately 180,000 residents. Most of the western half of Utah lies in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuticle
A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structure, function, and chemical composition. Human anatomy In human anatomy, "cuticle" can refer to several structures, but it is used in general parlance, and even by medical professionals, to refer to the thickened layer of skin surrounding fingernails and toenails (the eponychium), and to refer to the superficial layer of overlapping cells covering the hair shaft ( cuticula pili), consisting of dead cells, that locks the hair into its follicle. It can also be used as a synonym for the epidermis, the outer layer of skin. Cuticle of invertebrates In zoology, the invertebrate cuticle or cuticula is a multi-layered structure outside the epidermis of many invertebrates, notably arthropods and roundworms, in which it forms an exoskeleton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drumian
The Drumian is a stage of the Miaolingian Series of the Cambrian. It succeeds the Wuliuan and precedes the Guzhangian. The base is defined as the first appearance of the trilobite '' Ptychagnostus atavus'' around million years ago. The top is defined as the first appearance of another trilobite '' Lejopyge laevigata'' around million years ago. GSSP The GSSP is defined in the ''Drumian section'' () in the Drum Mountains, Millard County, Utah, United States. The stage was also named after the Drum Mountains. The section is an outcrop of the Wheeler Formation, a succession of calcareous shales. The precise base of the Drumian is a laminated limestone above the base of the Wheeler Formation. Major events The Cambrian Drumian carbon isotope excursion (DICE) event is associated with the beginning of this age. The cause of this event was the shallowing of anoxic deep waters simultaneously with their transgression. DICE hampered the recovery of reef ecosystems already affected by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptychagnostus
''Ptychagnostus'' is a genus of trilobites in the order Agnostida that lived during the Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ... period. Their remains are rarely found in empty tubes of the polychaete worm '' Selkirkia''. The genus probably ranged throughout the water column. It has two glabellar lobes, and three pygidial lobes. Type species ''Agnostus punctuosus'' Angelin, 1851 from the ''Ptychagnostus punctuosus'' zone of the Alum Shale ( Drumian), Sweden (by original designation). Official ruling on the conservation of accepted usage of ''A. punctuosus'' as the type species was given by the International Commission on Zoological Nomenclature, 1993. Remarks ''Ptychagnostus affinis'' (Brøgger 1878) was once considered a subspecies of ''Ptychagnostus punctuosu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
