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Sterechinus Antarcticus
''Sterechinus'' is a genus of sea urchins in the family Echinidae. All living members of the genus are found in the waters around Antarctica but the first species described in the genus was a fossil and was found in Europe. Description Members of the genus ''Sterechinus'' have compound ambulacral plates that are trigeminate (composed of three elements). These plates have a primary tubercle articulating with a spine on the middle element, a small secondary tubercle in the interambulacral groove on one side of it and 3 pairs of pores on the other. The tube feet are connected to these pores in the living animal and the pore pairs are arranged in a vertical arc. The sutures between the plates are deeply indented. The area of narrow plates around the mouth is small and the buccal notches are shallowly grooved. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterechinus Neumayeri
''Sterechinus neumayeri'', the Antarctic sea urchin, is a species of sea urchin in the family Echinidae. It is found living on the seabed in the waters around Antarctica. It has been used as a model organism in the fields of reproductive biology, embryology, ecology, physiology and toxicology. Molecular phylogeny The mitochondrial DNA of the Antarctic sea urchin and several other urchins found in the circumpolar region was examined in order to assess their phylogenetic relationships. It was found that ''Sterechinus neumayeri'' was most closely related to '' Paracentrotus lividus'' and '' Loxechinus albus'', both of which are found in the southernmost part of South America. The divergence of the three species began 35 to 25 million years ago, which coincides with the period at which Antarctica became separated from South America. Description The Antarctic sea urchin ranges in color from bright red to dull purple and can grow to in diameter. The test is globular with vertical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre Jean Édouard Desor
Pierre Jean Édouard Desor (13 February 1811, Friedrichsdorf, Grand Duchy of Hesse23 February 1882) was a German-Swiss geologist and naturalist. Biography Desor studied law at Giessen and Heidelberg, was compromised in the republican movements of 1832/3 (see, for example, Hambach Festival and Frankfurter Wachensturm), and escaped to Paris. Here his attention was drawn to geology. He made excursions with Élie de Beaumont, and in 1837 met Louis Agassiz at a meeting of naturalists in Neufchâtel. With Gressli and Vogt, Desor became an active collaborator with Agassiz, studying palaeontology and glacial phenomena, and contributing the essays for vol. iii. of Agassiz's ''Monographie d'echinodermes vivants et fossiles'' (Neufchâtel, 1842). Desor also published ''Excursions et sejours dans les glaciers et les hautes régions des Alpes de M. Agassiz et de ses compagnons de voyage'' (Neufchâtel, 1844). Together with James David Forbes, Desor ascended the Jungfrau in 1841. He was in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterechinus Dentifer
''Sterechinus'' is a genus of sea urchins in the family Echinidae. All living members of the genus are found in the waters around Antarctica but the first species described in the genus was a fossil and was found in Europe. Description Members of the genus ''Sterechinus'' have compound ambulacral plates that are trigeminate (composed of three elements). These plates have a primary tubercle articulating with a spine on the middle element, a small secondary tubercle in the interambulacral groove on one side of it and 3 pairs of pores on the other. The tube feet are connected to these pores in the living animal and the pore pairs are arranged in a vertical arc. The sutures between the plates are deeply indented. The area of narrow plates around the mouth is small and the buccal notches are shallowly grooved. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ole Theodor Jensen Mortensen
Ole Theodor Jensen Mortensen, also known as Theodor Mortensen (22 February 1868 – 3 April 1952) was a Danish scientist and professor at the Zoological Museum, Copenhagen. He specialized in sea urchins (Echinoidea) and provided an enormous marine collection to the museum. He collected many sea urchin species on his expeditions between 1899–1930.Mortensen Echinoids.nl Mortensen is the author of ''A Monograph of the echinoidea'' and ''Report on the echinoidea collected by the United States fisheries steamer "Albatross" during the Philippine expedition, 1907–1910''. Frog '' Sylvirana mortenseni
''Sylvirana mortenseni'' is a species of true frog. It is fo ...
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Sterechinus Agassizii
''Sterechinus'' is a genus of sea urchins in the family Echinidae. All living members of the genus are found in the waters around Antarctica but the first species described in the genus was a fossil and was found in Europe. Description Members of the genus ''Sterechinus'' have compound ambulacral plates that are trigeminate (composed of three elements). These plates have a primary tubercle articulating with a spine on the middle element, a small secondary tubercle in the interambulacral groove on one side of it and 3 pairs of pores on the other. The tube feet are connected to these pores in the living animal and the pore pairs are arranged in a vertical arc. The sutures between the plates are deeply indented. The area of narrow plates around the mouth is small and the buccal notches are shallowly grooved. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extant Taxon
Neontology is a part of biology that, in contrast to paleontology, deals with living (or, more generally, ''recent'') organisms. It is the study of extant taxa (singular: extant taxon): taxa (such as species, genera and families) with members still alive, as opposed to (all) being extinct. For example: * The moose (''Alces alces'') is an extant species, and the dodo (''Raphus cucullatus'') is an extinct species. * In the group of molluscs known as the cephalopods, there were approximately 600 extant species and 7,500 extinct species. A taxon can be classified as extinct if it is broadly agreed or certified that no members of the group are still alive. Conversely, an extinct taxon can be reclassified as extant if there are new discoveries of living species (" Lazarus species"), or if previously-known extant species are reclassified as members of the taxon. Most biologists, zoologists, and botanists are in practice neontologists, and the term neontologist is used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plio-Pleistocene
The Plio-Pleistocene is an informally described geological pseudo-period, which begins about 5 million years ago (Mya) and, drawing forward, combines the time ranges of the formally defined Pliocene and Pleistocene epochs—marking from about 5 Mya to about 12 kya. Nominally, the Holocene epoch—the last 12 thousand years—would be excluded, but most Earth scientists would probably treat the current times as incorporated into the term "Plio-Pleistocene"; see below. In the contexts of archaeology, paleontology, and paleoanthropology, the Plio-Pleistocene is a very useful period to which scientists may assign the long and continuous run in East Africa of datable sedimentary layers and their contents (e.g. the Bouri Formation). These contents collectively present a focused view of the continuous evolution of the region's large vertebrates, especially the evolution of some African apes ( hominids) to the earliest hominins; and then the development of the early humans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Miocene
The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million years ago) to 5.333 Ma. The evolution of life The gibbons (family Hylobatidae) and orangutans (genus ''Pongo'') are the first groups to split from the line leading to the hominins, including humans, then gorillas (genus ''Gorilla''), and finally, chimpanzees and bonobo The bonobo (; ''Pan paniscus''), also historically called the pygmy chimpanzee and less often the dwarf chimpanzee or gracile chimpanzee, is an endangered great ape and one of the two species making up the genus '' Pan,'' the other being the co ...s (genus '' Pan''). The splitting date between hominin and chimpanzee lineages is placed by some between 4 to 8 million years ago, that is, during the Late Miocene. References External links GeoWhen Database - Late Miocene .03 03 * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
