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Bulbaspis
''Bulbaspis'' ("bulb shield") is a late Ordovician genus of asaphid trilobites of the family Raphiophoridae found primarily in upper Ordovician-aged deepwater marine strata of Kazakhstan, China, and possibly Tasmania. Species of ''Bulbaspis'' are similar to other raphiophorids such as ''Ampyx'' and '' Raphiophorus'', save that the long spine that emanates from the glabella of the latter two genera has been modified into a knob-like or bulb-like structure in ''Bulbaspis'' that developed incrementally in the animal's growth.Zhiqiang, Zhou, and Zhou Zhiyi. "Late Ordovician trilobites from the Zhusilenghaierhan area, Ejin Banner, western Inner Mongolia, China."MEMOIR-ASSOCIATION OF AUSTRALASIAN PALAEONTOLOGISTS 32 (2006): 383. The function of the bulb is currently unknown: one hypothesis suggests sexual selection may have had a role in its evolution in the genus.Knell, Robert J., and Richard A. Fortey. "Trilobite spines and beetle horns: sexual selection in the Palaeozoic?." Biolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulbaspis Brevis
''Bulbaspis'' ("bulb shield") is a late Ordovician genus of Asaphida, asaphid trilobites of the family (biology), family Raphiophoridae found primarily in upper Ordovician-aged deepwater marine strata of Kazakhstan, China, and possibly Tasmania. Species of ''Bulbaspis'' are similar to other raphiophorids such as ''Ampyx (trilobite), Ampyx'' and ''Raphiophorus'', save that the long spine that emanates from the glabella of the latter two genera has been modified into a knob-like or bulb-like structure in ''Bulbaspis'' that developed incrementally in the animal's growth.Zhiqiang, Zhou, and Zhou Zhiyi. "Late Ordovician trilobites from the Zhusilenghaierhan area, Ejin Banner, western Inner Mongolia, China."MEMOIR-ASSOCIATION OF AUSTRALASIAN PALAEONTOLOGISTS 32 (2006): 383. The function of the bulb is currently unknown: one hypothesis suggests sexual selection may have had a role in its evolution in the genus.Knell, Robert J., and Richard A. Fortey. "Trilobite spines and beetle horns: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Trilobites
This list of trilobites is a comprehensive listing of all genera that have ever been included in the Arthropod class Trilobita, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful ('), or were not formally published ('), as well as junior synonyms of more established names, and genera that are no longer considered trilobites. A Aa *''Aayemenaytcheia'' Ab *'' Abadiella'' (=''Parabadiella''; =''Danagouia'') *'' Abakania'' *'' Abakanopleura'' *'' Abakolia'' (=''Costadiscus'') *'' Abdulinaspis'' *'' Abharella'' Ac *'' Acadolenus'' *''Acadoparadoxides'' (=''Entomolithus''; =''Entomostracites''; =''Eoparadoxides'') *'' Acanthalomina'' *'' Acanthocephalus'' (=''Alomataspis'') *'' Acanthometopus'' *'' Acanthomicmacca'' (=''Chengkouia''; =''Jaskovitchella''; =''Myopsomicmacca'') *'' Acanthoparypha'' *'' Acanthophillipsia'' *'' Acanthopleurella'' *'' Acanthopyge'' (=''Euarges'') *'' Acastava'' *' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raphiophoridae
Raphiophoridae is a family of small to average-sized trilobites that first occurred at the start of the Ordovician and became extinct at the end of the Middle Silurian. Anatomy All raphiophorids are blind, with headshields (or cephalons) that are triangular to subcircular, and many carry long, trailing genal spines, a forward-directed rapier-like spine on the central raised area (or glabella), or both, with the glabella often inflated and the natural fracture lines (or sutures) of the cephalon coinciding with its margin. The thorax typically has five to seven segments (except for the genera ''Taklamakania'', ''Pseudampyxina'', ''Nanshanaspis'', and ''Kongqiangheia'', which have only 3). As mentioned before, all raphiophorids are blind. Many, if not most, genera have no eyes whatsoever, though a few, such as '' Lehnertia'', have vestigial tubercles that correspond to the compound eyes of their ancestors. Distribution Raphiophoridae currently includes two officially recog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Union of Geological Sciences, Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician Trilobites Of Asia
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian Peri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asaphida Genera
Asaphida is a large, morphologically diverse order of trilobites found in marine strata dated from the Middle Cambrian until their extinction during the Silurian. Asaphida contains six superfamilies (Anomocaroidea, Asaphoidea, Cyclopygoidea, Dikelocephaloidea, Remopleuridoidea and Trinucleioidea), but no suborders. Asaphids comprise some 20% of described fossil trilobites. In 2020, the superfamily Trinucleoidea was proposed to be raised to an order ( Trinucleida) and removed from Asaphida. Morphology The Asaphids generally have cephalon (head) and pygidium (tail) parts similar in size, and most species have a prominent median ventral suture. Heads are often flat, and carapace furrows in the head area are often faint or not visible. Thoracic segments typically number 5 - 12, though some species have as few as two and some as many as 30. They also generally have a wide doublure, or rim, that surrounds the cephalon. This causes some specimens to be described as having a charact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Selection
Sexual selection is a mode of natural selection in which members of one biological sex mate choice, choose mates of the other sex to mating, mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex (intrasexual selection). These two forms of selection mean that some individuals have greater reproductive success than others within a population, for example because they are more Animal sexual behaviour, attractive or prefer more attractive partners to produce offspring. Successful males benefit from frequent mating and monopolizing access to one or more fertile females. Females can maximise the return on the energy they invest in reproduction by selecting and mating with the best males. The concept was first articulated by Charles Darwin who wrote of a "second agency" other than natural selection, in which competition between mate candidates could lead to speciation. The theory was given a mathematical basis by Ronald F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or dyna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tasmania
) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_date = Colony of Tasmania , established_title2 = Federation , established_date2 = 1 January 1901 , named_for = Abel Tasman , demonym = , capital = Hobart , largest_city = capital , coordinates = , admin_center = 29 local government areas , admin_center_type = Administration , leader_title1 = Monarch , leader_name1 = Charles III , leader_title2 = Governor , leader_name2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ampyx (trilobite)
''Ampyx'' is an Ordovician-Silurian genus of Asaphid trilobites of the family Raphiophoridae. Species of ''Ampyx'' are characterized by three extended spines on the head-shield, one spine derived from each free cheek, and one spine emanating from the glabellum. Species include ''Ampyx linleyensis'' ( Lanvirn-Caradoc series). Species of ''Ampyx'' grew to an average length of . Collective behaviour Fossils of the trilobite ''Ampyx priscus'', dating back about 480 million years ago, have been recently described as clustered in lines along the ocean floor. The animals were all mature adults, and were all facing the same direction as though they had formed a conga line or a peloton. It has been suggested they line up in this manner to migrate, much as spiny lobsters migrate in single-file queues. Or perhaps they are getting together for mating. The findings suggest animal collective behaviour has very early evolutionary origins.Vannier J, Vidal M, Marchant R, El Hariri K, Kourais ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbekistan to the south, and Turkmenistan to the southwest, with a coastline along the Caspian Sea. Its capital is Astana, known as Nur-Sultan from 2019 to 2022. Almaty, Kazakhstan's largest city, was the country's capital until 1997. Kazakhstan is the world's largest landlocked country, the largest and northernmost Muslim-majority country by land area, and the ninth-largest country in the world. It has a population of 19 million people, and one of the lowest population densities in the world, at fewer than 6 people per square kilometre (15 people per square mile). The country dominates Central Asia economically and politically, generating 60 percent of the region's GDP, primarily through its oil and gas industry; it also has vast mineral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
