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Holyoakia
''Holyoakia'' is a genus of very small (up to 7½ mm long) trilobites of the family Dorypygidae, from the late Lower Cambrian (Late Botonian) of South Australia and Antarctica. Etymology ''H. simpsoni'' was named in honor of David Simpson from Adelaide, who collected the first specimens. Distribution * ''H. granulosa'' has only been collected from the late Lower Cambrian of Antarctica (presumably Botomian, Shackleton Limestone, Central Transantarctic Mountains) * ''H. simpsoni'' only occurs in the late Lower Cambrian of South Australia (mid-late Botomian, Emu Bay Shale, Big Gully, Kangaroo Island). Taxonomy The genus was originally with reservation placed in the Emuellidae. The genus however lacks the specific characteristics of this family, most notably, the clearly furrowed glabella that is rounded at the frontal end, the hook-shaped eye ridges that run parallel to the margin of the head shield (or cephalon), clearly distinguishable prothorax of six segments, the most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emu Bay Shale
The Emu Bay Shale is a geological formation in Emu Bay, South Australia, containing a major Konservat-Lagerstätte (fossil beds with soft tissue preservation). It is one of two in the world containing Redlichiidan trilobites. The Emu Bay Shale is dated as Cambrian Series 2, Stage 4, correlated with the upper Botomian Stage of the Lower Cambrian. Its mode of preservation is the same as the Burgess shale, but the larger grain size of the Emu Bay rock means that the quality of preservation is lower. More than 50 species of trilobites, non-biomineralized arthropods, palaeoscolecids, a lobopodian, a polychaete, vetulicolians, nectocaridids, hyoliths, brachiopods, sponges, chancelloriids, and a chelicerate are known from the Emu Bay Shale. Description The Emu Bay Shale of Kangaroo Island, South Australia, is Australia's only known Burgess-Shale-type Konservat-Lagerstätte, and includes faunal elements such as ''Anomalocaris'', ''Tuzoia'', ''Isoxys'', and '' Wronascolex'', in commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emuellidae
Emuellidae are a small family of trilobites, a group of extinct marine arthropods, that lived during the late Lower Cambrian (late Botomian) of the East Gondwana supercontinent, in what are today South-Australia and Antarctica. Emuellidae can be recognized among trilobites in having a set of unique features. The headshield or cephalon has large genal spines reaching back as far as the 3rd to 6th segment of the thorax. The eye-ridges contact the back of the frontal lobe of the glabella and extend laterally and backwards, roughly parallel to the frontal and lateral rim of the cephalon. There are small, clearly incised pits at the junction between the eye-ridge and the frontal lobe of the cephalic axis (or glabella). The thorax reaches its greatest width at the 6th segment. The frontal part or prothorax consists of 6 segments, with number 5 and 6 fused, and the 6th carrying very large trailing spines. The rear part or opistothorax consists of a variable but extremely large number of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shackleton Limestone
The Shackleton Limestone is a Cambrian limestone formation of the Byrd Group of Antarctica. The age of the formation is established to be Cambrian Stage 3, dated at ranging from 520 to 516 Ma. This period correlates with the End-Botomian mass extinction. Fossils of trilobites and '' Marocella mira'' and ''Dailyatia'' have been found in the formation, named after Ernest Shackleton, who led a failed expedition into Antarctica. At time of deposition, the Antarctic Plate has been established to be just south of the equator as part of the supercontinent Pannotia, contrasting with its present position at 82 degrees southern latitude.Shackleton Limestone at .org |
Trilobites Of Antarctica
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 st ... [...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] |
Corynexochida Genera
Corynexochida is an order of trilobite that lived from the Lower Cambrian to the Late Devonian. Like many of the other trilobite orders, Corynexochida contains many species with widespread characteristics. The middle region of the cephalon (the glabella) is typically elongate, with the sides often spreading forward (pestle-shaped). Some species have glabellae that are ''effaced'', meaning they are smooth and show little detail. The glabellar furrows (when not effaced) typically have a splayed arrangement. In most species, the hind pair on either side of the cephalon become spines that point sharply backwards, and the spinose tips of the anterior pairs of thoracic segments tend to become more and more forward directed toward the pygidium The pygidium (plural pygidia) is the posterior body part or shield of crustaceans and some other arthropods, such as insects and the extinct trilobites. In groups other than insects, it contains the anus and, in females, the ovipositor. It is c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australian Trilobite References
Australian(s) may refer to: Australia * Australia, a country * Australians, citizens of the Commonwealth of Australia ** European Australians ** Anglo-Celtic Australians, Australians descended principally from British colonists ** Aboriginal Australians, indigenous peoples of Australia as identified and defined within Australian law * Australia (continent) ** Indigenous Australians * Australian English, the dialect of the English language spoken in Australia * Australian Aboriginal languages * ''The Australian'', a newspaper * Australiana, things of Australian origins Other uses * Australian (horse), a racehorse * Australian, British Columbia, an unincorporated community in Canada See also * The Australian (other) * Australia (other) * * * Austrian (other) Austrian may refer to: * Austrians, someone from Austria or of Austrian descent ** Someone who is considered an Austrian citizen, see Austrian nationality law * Austrian German dialect * Someth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megapharanaspis
''Megapharanaspis nedini'' is a small (maximally ) trilobite of the superfamily Emuelloidea, within which it occupies a family on its own. Its fossils have been found in the Lower Cambrian of South-Australia. Etymology The genus name composed of the Greek μέγας (mega), meaning ''great'', pharangos, meaning gully, and ἀσπίς (aspis) shield, referencing Big Gully on Kangaroo Island, the only known site where fossils of ''Megapharanaspis'' were collected. The species epithet An epithet (, ), also byname, is a descriptive term (word or phrase) known for accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, di ... ''nedini'' is in honor of Dr. Chris Nedin. References Cambrian trilobites of Australia Emuelloidea Redlichiida genera {{Redlichiida-stub Cambrian genus extinctions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balcoracania
''Balcoracania dailyi'' is a small (typically about ) trilobite of the family Emuellidae. Its fossils have been found in south Australia and Antarctica. It can be recognised by a short field between the front of the axis in the head (or glabella) and the border ridge, and a semi-circular headsheald, as compared to touching glabella and border, and the sub-pentagonal head, in the sister-genus ''Emuella''. Both emuellid genera share eye ridges that are positioned parallel to the frontal and lateral border of the head, prominent genal spines that are a smooth continuation of the lateral margin of the head, a prothorax of 6 segments, with the 5th and 6th merged and carrying large trailing spines. Both genera have in adulthood a highly variable but large number of segments of the opistothorax, although the largest number found in ''B. dailyi'' with 97 is much larger than in ''Emuella'' (52). ''B. dailyi'' is the only known species in this genus (i.e., the genus is monotypic). Etymology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estaingia Bilobata
''Estaingia bilobata'' is a species of trilobite from the lower 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 ... period. Their fossils are found chiefly in Australia. References * * * * * Estaingiidae Cambrian trilobites of Australia Emu Bay Shale {{Ptychopariida-stub Cambrian genus extinctions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redlichia Takooensis
''Redlichia takooensis'' is a species of redlichiid trilobite from the lower Cambrian-aged Emu Shale of Kangaroo Island, Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma .... References * * * * * Redlichioidea Cambrian trilobites Fossil taxa described in 1950 Emu Bay Shale {{Redlichiida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Botomian
Cambrian Stage 4 is the still unnamed fourth stage of the Cambrian and the upper stage of Cambrian Series 2. It follows Cambrian Stage 3 and lies below the Wuliuan. The lower boundary has not been formally defined by the International Commission on Stratigraphy. One proposal is the first appearance of two trilobite genera, ''Olenellus'' or ''Redlichia''. Another proposal is the first appearance of the trilobite species '' Arthricocephalus chauveaui''. Both proposals will set the lower boundary close to million years ago. The upper boundary corresponds to the beginning of the Wuliuan. Naming The International Commission on Stratigraphy The International Commission on Stratigraphy (ICS), sometimes referred to unofficially as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigra ... has not named the fourth stage of the Cambrian yet. In the widely used Siberian nomenclature stage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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