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Echmatocrinus
''Echmatocrinus'' is a Cambrian animal which resembles a crinoid or an octocoral. Its exact taxonomy is still a subject of debate. It is known only from the Burgess shale. 5 specimens of ''Echmatocrinus'' are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community. The creature was a little like an inverted cone, with a crown of seven to nine tentacles. Each tentacle was covered with small extensions. The cone itself was covered with irregularly arranged mineralised plates. The organisms lived a solitary lifestyle, although juveniles are sometimes attached to (or budding from) adults. References External links *Further reading Ausich, W. I. 1998a. Early phylogeny and subclass division of the Crinoidea (phylum Echinodermata). Journal of Paleontology 72 (3): 499–510. Ausich, W. I. 1998b. Origin ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crinoid
Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are members of the largest crinoid order, Comatulida. Crinoids are echinoderms in the phylum Echinodermata, which also includes the starfish, brittle stars, sea urchins and sea cucumbers. They live in both shallow water and in depths as great as . Adult crinoids are characterised by having the mouth located on the upper surface. This is surrounded by feeding arms, and is linked to a U-shaped gut, with the anus being located on the oral disc near the mouth. Although the basic echinoderm pattern of fivefold symmetry can be recognised, in most crinoids the five arms are subdivided into ten or more. These have feathery pinnules and are spread wide to gather planktonic particles from the water. At some stage in their lives, most crinoids have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian
The Cambrian Period ( ; sometimes symbolized C with bar, 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 Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octocoral
Octocorallia (also known as Alcyonaria) is a class of Anthozoa comprising around 3,000 species of water-based organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians (sea fans and sea whips) within three orders: Alcyonacea, Helioporacea, and Pennatulacea. These organisms have an internal skeleton secreted by mesoglea and polyps with eight tentacles and eight mesentaries. As with all Cnidarians these organisms have a complex life cycle including a motile phase when they are considered plankton and later characteristic sessile phase. Octocorals have existed at least since the Ordovician period, as shown by Maurits Lindström's findings in the 1970s, however recent work has shown a possible Cambrian origin. Biology Octocorals resemble the stony corals in general appearance and in the size of their polyps, but lack the distinctive stony skeleton. Also unlike the stony corals, each polyp has only eight tentacles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burgess Shale
The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. It is famous for the exceptional preservation of the soft parts of its fossils. At old (middle Cambrian), it is one of the earliest fossil beds containing soft-part imprints. The rock unit is a black shale and crops out at a number of localities near the town of Field in Yoho National Park Yoho National Park ( ) is a National Parks of Canada, national park of Canada. It is located within the Canadian Rockies, Rocky Mountains along the western slope of the Continental Divide of the Americas in southeastern British Columbia, bordered ... and the Kicking Horse Pass. Another outcrop is in Kootenay National Park 42 km to the south. History and significance The Burgess Shale was discovered by palaeontologist Charles Doolittle Walcott, Charles Walcott on 30 August 1909, towards the end of the season's fieldwork. He returned in 1910 with his sons, daughter, and wif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the source of 95% of the fossils he collected during this time; tens of thousands of soft-bodied fossils representing over 150 genera have been recovered from the Phyllopod bed alone. Stratigraphy and location The phyllopod bed is a 2.31 m thick layer of the 7 m thick Greater Phyllopod Bed, found in the Walcott Quarry on Fossil Ridge, between Wapta Mountain and Mount Field, at an elevation of around , around north of the railway town of Field, British Columbia, in the Canadian Rocky Mountains. It is adjacent to Mount Burgess, where Walcott first discovered the Burgess Shale formation. Walcott divided the bed into twelve units based on the rock type and fossil content. Certain fossil beds provide reference levels and can b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burgess Shale Fossils
The fossils of the Burgess Shale, like the Burgess Shale itself, formed around 505 million years ago in the Mid Cambrian period. They were discovered in Canada in 1886, and Charles Doolittle Walcott collected over 65,000 specimens in a series of field trips up to the alpine site from 1909 to 1924. After a period of neglect from the 1930s to the early 1960s, new excavations and re-examinations of Walcott's collection continue to reveal new species, and statistical analysis suggests that additional discoveries will continue for the foreseeable future. Stephen Jay Gould's book '' Wonderful Life'' describes the history of discovery up to the early 1980s, although his analysis of the implications for evolution has been contested. The fossil beds are in a series of shale layers, averaging and totalling about in thickness. These layers were deposited against the face of a high undersea limestone cliff. All these features were later raised up above current sea level during the cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enigmatic Prehistoric Animal Genera
Enigmatic is an adjective meaning "mysterious" or "puzzling". It may also refer to: * ''Enigmatic'', a 1970 album by Czesław Niemen * '' Enigmatic: Calling'', a 2005 album by Norwegian progressive metal band Pagan's Mind * Enigmatic scale, musical scale used by Verdi and others * "The Enigmatic", a song by Joe Satriani on the album '' Not of This Earth'' See also * Enigmatic leaf turtle, a species of Asian leaf turtle * Enigmatic moray eel, a species found in the Pacific and Indian Oceans * ''Glaresis ''Glaresis'' is a genus of beetles, sometimes called "Enigmatic scarab beetles", in its own family, the Glaresidae. It is closely related to, and was formerly included in, the family Scarabaeidae. Although its members occur in arid and sandy area ...'', a genus of beetles sometimes called "enigmatic scarab beetles" * Enigma (other) {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 1973
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 absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
