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Protichnites
''Protichnites'' is an ichnogenus of trace fossil consisting of the imprints made by the walking activity of certain arthropods. It consists of two rows of tracks and a medial furrow between the two rows. This furrow, which may be broken, set at an angle, and of varying width and depth, is thought to be the result of the tail region contacting the substrate. The first footprints on land Sir Richard Owen, the noted British paleontologist and anatomist who coined the term “ Dinosauria”, based ''Protichnites'' on trackways that were shipped to him from the Cambrian Potsdam Sandstone of Quebec.Owen, 1851 He was correct in recognizing that these were the oldest known footprints on land, having been produced in intertidal and supratidal environments during what would now be called Cambrian times.Collette and Hagadorn, 2010 The ''Protichnites'' makers Owen first thought that these trackways were made by tortoises, but new material convinced him that “articulates” (a group th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blackberry Hill
Blackberry Hill is a Konservat-Lagerstätte of Cambrian age located within the Elk Mound Group in Marathon County, Wisconsin. It is found in a series of quarries and outcrops that are notable for their large concentration of exceptionally preserved trace fossils in Cambrian tidal flats. One quarry in particular also has the distinction of preserving some of the first land animals. These are preserved as three-dimensional casts, which is unusual for Cambrian animals that are only lightly biomineralized.Collette and Hagadorn, 2010 Additionally, Blackberry Hill is the first occurrence recognized to include Cambrian mass strandings of scyphozoans (jellyfish).Getty and Hagadorn, 2008 Age and stratigraphic placement The strata at Blackberry Hill are known to belong to the Elk Mound Group;Schieber et al., 2007 however, the lack of good stratigraphic markers (i.e., index fossils) in some Blackberry Hill localities, coupled with uncertainties about the age range of the Elk Mound Gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trace Fossil
A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, which are the fossilized remains of parts of organisms' bodies, usually altered by later chemical activity or mineralization. The study of such trace fossils is ichnology and is the work of ichnologists. Trace fossils may consist of impressions made on or in the substrate by an organism. For example, burrows, borings (bioerosion), urolites (erosion caused by evacuation of liquid wastes), footprints and feeding marks and root cavities may all be trace fossils. The term in its broadest sense also includes the remains of other organic material produced by an organism; for example coprolites (fossilized droppings) or chemical markers (sedimentological structures produced by biological means; for example, the formation of stromatolites). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian Arthropods
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] |
Cambrian
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Owen
Sir Richard Owen (20 July 1804 – 18 December 1892) was an English biologist, comparative anatomist and paleontologist. Owen is generally considered to have been an outstanding naturalist with a remarkable gift for interpreting fossils. Owen produced a vast array of scientific work, but is probably best remembered today for coining the word '' Dinosauria'' (meaning "Terrible Reptile" or "Fearfully Great Reptile"). An outspoken critic of Charles Darwin's theory of evolution by natural selection, Owen agreed with Darwin that evolution occurred, but thought it was more complex than outlined in Darwin's ''On the Origin of Species''. Owen's approach to evolution can be considered to have anticipated the issues that have gained greater attention with the recent emergence of evolutionary developmental biology. Owen was the first president of the Microscopical Society of London in 1839 and edited many issues of its journal – then known as '' The Microscopic Journal''. Owen als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosineia
''Mosineia'' is a genus of euthycarcinoid arthropods that lived on tidal flats of Laurentia at what is now central Wisconsin from the Middle Cambrian to the Late Cambrian. It contains a single species, ''Mosineia macnaughtoni''. Associated trace fossil evidence suggests that this genus spent some of its time subaerially, possibly to mate and to feed on the microbial mats that blanketed the beaches. The genus is named after Mosinee---the city in Marathon County, Wisconsin, near which the fossils were found. The collecting site is known as Blackberry Hill, which is a well known Konservat-Lagerstätte that produces abundant exceptionally preserved fossils. History of discovery The discovery of ''Mosineia'' was a milestone in geologic history. Since the mid-1800s, trackways named ''Protichnites ''Protichnites'' is an ichnogenus of trace fossil consisting of the imprints made by the walking activity of certain arthropods. It consists of two rows of tracks and a medial f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potsdam Sandstone
The Potsdam Sandstone, more formally known as the Potsdam Group, is a geologic unit of mid-to-late Cambrian age found in Northern New York and northern Vermont and Quebec and Ontario. A well-cemented sandstone of nearly pure quartz, in the 19th century it was widely used in construction and in refractory linings for iron furnaces.James CarlPotsdam Sandstone: Composition and Qualities Potsdam Public Museum website, accessed July 29, 2011 Name and type locality The Potsdam Sandstone is named for its type locality in Potsdam, New York, where in 1838 Ebenezer Emmons described it in outcrops along the Raquette River.Geologic Unit: Potsdam Geolex Database, accessed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euthycarcinoid
Euthycarcinoidea are an enigmatic group of extinct possibly amphibious arthropods that ranged from Cambrian to Triassic times. Fossils are known from Europe, North America, Argentina, Australia and Antarctica. Description The euthycarcinoid body was divided into a cephalon (head), preabdomen, and postabdomen. The cephalon consisted of two segments and included mandibles, antennae and presumed eyes. The preabdomen consisted of five to fourteen tergites, each having up to three somites. Each somite had in turn a pair of uniramous, segmented legs. The postabdomen was limbless and consisted of up to six segments and a terminal tail spine. Affinities Due to its particular combination of characteristics, the position of the Euthycarcinoidea within the Arthropoda has been ambiguous; previous authors have allied euthycarcinoids with crustaceans (interpreted as copepods, branchiopods, or an independent group), with trilobites, or the merostomatans (horseshoe crabs and sea scorpions, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplichnites
''Diplichnites'' are arthropod trackways with two parallel rows of blunt to elongate, closely spaced tracks oriented approximately perpendicularly to the mid-line of the trackway. The term is more often used for the ichnofossils of this description; however, similar trackways from recent arthropods are sometimes given this name as well. The ''Diplichnites'' makers This type of trackway was originally based on large fossils from Pennsylvanian strata of Nova Scotia, when Sir J. W. Dawson named it in 1873. Dawson proposed that ''Diplichnites'' were produced by a fish “walking” in shallow water on pectoral or ventral fin spines. Previous to this he had suggested that a large crustacean, annelid worm or myriapod (such as a millipede) could have made them. Subsequent evidence has supported this earlier interpretation. The fossils on which this ichnotaxon was based are now thought to be from giant myriapods, such as ''Arthropleura''. The Scottish ''Diplichnites cuithensis'' cou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplexus
Amplexus (Latin "embrace") is a type of mating behavior exhibited by some externally fertilizing species (chiefly amphibians and horseshoe crabs) in which a male grasps a female with his front legs as part of the mating process, and at the same time or with some time delay, he fertilizes the eggs, as they are released from the female's body. In amphibians, females may be grasped by the head, waist, or armpits, and the type of amplexus is characteristic of some taxonomic groups. Amplexus involves direct contact between male and female, distinguished from other forms of external fertilization, such as broadcast spawning, where sperm and eggs are freely shed into water without direct contact by individuals. In order for amplexus to be initiated, male frogs must first find a mate by attracting one through calls, typically in the evening. Once a male has successfully attracted a mate, the process of amplexus begins, while the unsuccessful males are forced to continue their search for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2019 '' Journal Citation Reports'' (with an ascribed impact factor of 42.778), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in autumn 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander Macmillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the journal; ''Nature'' redoubled its efforts in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lethaia
''Lethaia'' is a quarterly peer-reviewed scientific journal of Earth science, covering research on palaeontology and stratigraphy. Now published by Wiley-Blackwell, it was originally published by the International Commission on Stratigraphy. It is an official publication of the International Palaeontological Association and the International Commission on Stratigraphy. The journal had a 2012 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... of 2.488, ranking it 7th out of 48 journals in the category "Paleontology", though its IF has since declined. References External links * Paleontology journals Wiley-Blackwell academic journals English-language journals Publications established in 1968 Quarterly journals {{paleontology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
