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Buenellus
''Buenellus higginsi'' is an average size (about ) trilobite, which lived during the Lower Cambrian period, in what is now North-West Greenland. It is a prominent member of the Sirius Passet fauna. ''Buenellus higginsi'' is the only known species in the genus ''Buenellus'' (i.e., the genus is monotypic). Etymology The genus name is a contraction of Buen, from the formation in which it was first collected, and ''Olenellus'', a somewhat related trilobite genus. The species specific epithet honors A. Higgins, who discovered the Sirius Passet ' in 1984 during the Geological Survey of Greenland. Description The general outline of the body is rounded n the front third, parallel sided in the middle third, and progressively tapering backwards in the back third, ending at an angle of approximately 45° with the midline. The headshield (or cephalon is approximately ⅝× as long as it is wide. The (in this case only slightly) vaulted central axis of the head or glabella tapers gently ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buen Formation
The Buen Formation is a geologic formation and Lagerstätte in Peary Land, North Greenland. The shale preserves fossils dating back to the Early Cambrian period (Atdabanian in the local timescale, about 520 to 513 Ma).Buen Formation at .org Description The oldest Cambrian series of the area was deposited in the Franklinian Basin and is poorly exposed in fragmentary, heavily metamorphosed outcrops in . It was emplaced during the ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nevadella
''Nevadella'' is an extinct genus of trilobites, fossil marine arthropods, with species of average size (about long). It lived during the late Atdabanian stage, which lasted from 530 to 524 million years ago during the early part of the Cambrian Period. Etymology The name is derived from ''Nevadia'', a related genus. Taxonomy ''Nevadia'' predates ''Nevadella'' and may include its direct ancestor. Species previously assigned to ''Nevadella'' * ''N. burri'' = ''Pleisionevadella burri'' Description The body of ''Nevadella'' is very flat dorso-ventrally. The general outline of its thin, lightly calcified exoskeleton is inverted drop-shaped. The front is rounded, widest at the back of the headshield (or cephalon), and tapering from there to an eventually rounded termination. The central area of the cephalon (or glabella) is distinctly tapered forward, sides slightly concave, but wedging out slightly in the frontal half and with a rounded front (like the silhouette of a slim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period () and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out. The last extant trilobites finally disappeared in the mass extinction at the end of the Permian about 252 million years ago. Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described. By the time trilobites first appeared in the fossil record, they were already highly diversified and geographically dispersed. Because trilobites had wide diversity and an easily fossilized exoskeleton, they left an extensive fossil record. The stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period () and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out. The last extant trilobites finally disappeared in the mass extinction at the end of the Permian about 252 million years ago. Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described. By the time trilobites first appeared in the fossil record, they were already highly diversified and geographically dispersed. Because trilobites had wide diversity and an easily fossilized exoskeleton, they left an extensive fossil record. The stu ... [...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 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 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 . Preservation The preservation of the Sirius Passet is traditionall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atdabanian
Cambrian Stage 3 is the still unnamed third stage of the Cambrian. It succeeds Cambrian Stage 2 and precedes Cambrian Stage 4, although neither its base nor top have been formally defined. The plan is for its lower boundary to correspond approximately to the first appearance of trilobites, about million years ago, though the globally asynchronous appearance of trilobites warrants the use of a separate, globally synchronous marker to define the base. The upper boundary and beginning of Cambrian Stage 4 is informally defined as the first appearance of the trilobite genera ''Olenellus'' or '' Redlichia'' around million years ago. Naming The International Commission on Stratigraphy has not officially named the 3rd stage of the Cambrian. The stage approximately corresponds to the "Atdabanian", which is used by geologists working in Siberia. Biostratigraphy The oldest trilobite known is ''Lemdadella'' which appears at the beginning of the '' Fallotaspis'' zone. The Cambrian radiatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils Of Greenland
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian Greenland
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established as "Cambrian series" by Adam Sedgwick, who named it after Cambria, the Latin name for 'Cymru' (Wales), where Britain's Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large "Transition Series", although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian Trilobites
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established as "Cambrian series" by Adam Sedgwick, who named it after Cambria, the Latin name for 'Cymru' (Wales), where Britain's Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large "Transition Series", although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Arthropod Genera
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulletin Of Geosciences
The ''Bulletin of Geosciences'' is a peer-reviewed scientific journal publishing original research papers, review articles, and short contributions. It covers all aspects of palaeoenvironmental geology, including palaeontology, stratigraphy, sedimentology, palaeogeography, palaeoecology, palaeoclimatology, geochemistry, mineralogy, geophysics, and related fields. It is published by the Czech Geological Survey, West Bohemian Museum in Plzeň, Palacký University Olomouc and the Geological institute of Czech Academy of Sciences. Abstracting and indexing This journal is abstracted and indexed in: * Science Citation Index Expanded * Current Contents/Physical, Chemical & Earth Sciences * Scopus * GeoRef The journal is included in the Geoscience e-Journals collection. According to the ''Journal Citation Reports'', the journal has a 2013 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laurentia
Laurentia or the North American Craton is a large continental craton that forms the ancient geological core of North America. Many times in its past, Laurentia has been a separate continent, as it is now in the form of North America, although originally it also included the cratonic areas of Greenland and also the northwestern part of Scotland, known as the Hebridean Terrane. During other times in its past, Laurentia has been part of larger continents and supercontinents and itself consists of many smaller terranes assembled on a network of Early Proterozoic orogenic belts. Small microcontinents and oceanic islands collided with and sutured onto the ever-growing Laurentia, and together formed the stable Precambrian craton seen today. The craton is named after the Laurentian Shield, through the Laurentian Mountains, which received their name from the Saint Lawrence River, named after Lawrence of Rome. Interior platform In eastern and central Canada, much of the stable craton is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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