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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 thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elrathia Kingii
''Elrathia'' is a genus of trilobite belonging to Ptychopariacea known from the mid-Cambrian of Laurentia (North America). ''E. kingii'' is one of the most common trilobite fossils in the USA locally found in extremely high concentrations within the Wheeler Formation in the U.S. state of Utah. ''E. kingii'' has been considered the most recognizable trilobite. Commercial quarries extract ''E. kingii'' in prolific numbers, with just one commercial collector estimating 1.5 million specimens extracted in a 20-year career. 1950 specimens of ''Elrathia'' are known from the Greater Phyllopod bed, where they comprise 3.7% of the community. Etymology Even though the generic name ''Elrathia'' was first published in the combination ''E. kingii'', a species from the House Range, Utah, the name, itself, is derived from Elrath, Cherokee County, Alabama. Description ''E. kingii'' is a medium-sized trilobite with a smooth sub-ovate carapace that is tapered towards the rear. Thorax is usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burgess Shale Type Preservation
The Burgess Shale of British Columbia is famous for its exceptional preservation of mid-Cambrian organisms. Around 69 other sites have been discovered of a similar age, with soft tissues preserved in a similar, though not identical, fashion. Additional sites with a similar form of preservation are known from the Ediacaran and Ordovician periods. These various shales are of great importance in the reconstruction of the ecosystems immediately after the Cambrian explosion. The taphonomic regime results in soft tissue being preserved, which means that organisms without hard parts that could be conventionally fossilised can be seen; also, we gain an insight into the organs of more familiar organisms such as the trilobites. The most famous localities preserving organisms in this fashion are the Canadian Burgess Shale, the Chinese Chengjiang fauna, and the more remote Sirius Passet in north Greenland. However, a number of other localities also exist. Distribution Burgess Shale-type biota ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Algae
The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as sister of the Zygnematophyceae. Since the realization that the Embryophytes emerged within the green algae, some authors are starting to properly include them. The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae. Many species live most of their lives as single cells, while other species form coenobia (colonies), long filaments, or highly differentiated macroscopic seaweeds. A few other organi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanobacteria
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not usually scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in plast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marpolia
''Marpolia'' has been interpreted as a cyanobacterium, but also resembles the modern cladophoran green algae. It is known from the Middle Cambrian Burgess shale and Early Cambrian deposits from the Czech Republic. It comprises a dense mass of entangled, twisted filaments. It may have been free-floating or grown on other objects, although there is no evidence of attachment structures. 40 specimens of ''Marpolia'' are known from the Greater Phyllopod bed The Phyllopod bed, designated by USNM locality number 35k, is the most famous fossil-bearing member of the Burgess Shale fossil ''Lagerstätte''. It was quarried by Charles Walcott from 1911–1917 (and later named Walcott Quarry), and was t ..., where they comprise 0.08% of the community. References External links * Burgess Shale fossils Wheeler Shale Prehistoric bacteria {{cyanobacteria-stub Cambrian genus extinctions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protista
A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exclusion of other eukaryotes means that protists do not form a natural group, or clade. Therefore, some protists may be more closely related to animals, plants, or fungi than they are to other protists. However, like the groups ''algae'', ''invertebrates'', and ''protozoans'', the biological category ''protist'' is used for convenience. Others classify any unicellular eukaryotic microorganism as a protist. The study of protists is termed protistology. History The classification of a third kingdom separate from animals and plants was first proposed by John Hogg in 1860 as the kingdom Protoctista; in 1866 Ernst Haeckel also proposed a third kingdom Protista as "the kingdom of primitive forms". Originally these also included prokaryotes, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanleycaris Sp
''Stanleycaris'' is an extinct, monotypic genus of hurdiid radiodont from the middle Cambrian (Miaolingian). The type species is ''Stanleycaris hirpex''. ''Stanleycaris'' was described from the Stephen Formation near the Stanley Glacier and Burgess Shale locality of Canada, as well as Wheeler Formation of United States. The genus was characterized by the rake-like frontal appendages with robust inner spines. ''Stanleycaris'' was originally described only from frontal appendages and oral cone. However, in 2022, 268 specimens of ''Stanleycaris'', many of which were complete, were studied, making ''Stanleycaris'' a well documented radiodont. ''Stanleycaris'' had three eyes, a bizarre configuration previously unknown among other radiodont genera; yet this head anatomy supports early differentiation among arthropod head and trunk segmentation. The original description of the taxon appeared in an online supplement to the article published by Jean-Bernard Caron, Robert R. Gaines, M. G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite Zone
Trilobites are used as index fossils to subdivide the Cambrian period. Assemblages of trilobites define trilobite zones. The ''Olenellus''-zone has traditionally marked the top of the Lower Cambrian, and is followed by the '' Eokochaspis'' zone. The last two zones of the Middle Cambrian are the '' Bathyuriscus– Elrathina''-zone (contemporaneous with the Burgess Shale) and the subsequent '' Bolaspidella''-zone (starting at the base of the Drumian stage). These are overlain by the lowermost Upper Cambrian ''Cedaria''-zone. Alternative zoning names place the Burgess Shale in the ''Peronopsis bonnerensis''-zone, which is underlain by the ''Oryctocephalus indicus''-zone (e.g. Spence Shale) and overlain (perhaps not directly) by the ''Ptychagnostus punctuosus''-zone. The lower Middle Cambrian '' Glossopleura''-zone (Spence Shale) is above the '' Albertella''-zone. The '' Elvinia''-zone is upper Cambrian. Subdivision of the ''Olenellus''-zone Recently, it has been proposed to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptychagnostus
''Ptychagnostus'' is a member of the agnostida that lived during the Cambrian period. Ptychagnostidae generally do not exceed one centimetre in length. 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 ''Pt. 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 ''Pt. punctuosus''. Laurie (2008) grouped ''punctuosus'' and ''affinis'' within ''Ptychagnostus'', but preferred to place the closely related ''atavus'' within ''Acidusus''. Ptychagnostidae Genera Høyberget & Bruton (2008) HØYBERGET M. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emeraldella Brocki
''Emeraldella'' is a genus of arthropod known from the Middle Cambrian of North America. The type species ''E. brocki'' was described in 1912 from the Burgess Shale. 21 specimens of ''Emeraldella'' are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community. A re-study on the species was done in 2012. A second species ''E. brutoni'' is known from the , which was described in 2011. An additional specimen of ''E. brutoni'' was described in 2019, which revealed more of the anatomy. It has been placed as part of the , a group of arthropods containing |
