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Sato's Beaked Whale
Sato's beaked whale (''Berardius minimus'') is a little-known species of four-toothed whale. Description Sato's beaked whale is one of the poorly distinguished species in the genus ''Berardius''. It was distinguished from Arnoux's and Baird's beaked whale in 2019 on the basis of mtDNA differences. It generally has a short beak (~4% body length). While other four-toothed whales are generally grey with scars, kurotsuchis usually have few linear scars, so that the dark, smooth skin contrasts highly with round, white scars of about 5 cm diameter (from cookiecutter shark bites). The common name for ''Berardius minimus'' is in recognition of Hal Sato, a Hokkaido-based researcher whose photographs of the whales helped to distinguish this species from other beaked whales (note the image credit iFigure 1anFigure 2from the Yamada ''et. al.'' paper ). Distribution The species' distribution, based on genetic samples from strandings only, is believed to include the sea around Japan, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Miocene
The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was p .... The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million years ago). During this period, a sharp drop in global temperatures took place. This event is known as the Middle Miocene Climate Transition. For the purpose of establishing European Land Mammal Ages this sub-epoch is equivalent to the Astaracian age. External links GeoWhen Database - Middle Miocene .02 02 * * {{geochronology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scale Bar
A linear scale, also called a bar scale, scale bar, graphic scale, or graphical scale, is a means of visually showing the scale of a map, nautical chart, engineering drawing, or architectural drawing. A scale bar is common element of map layouts. On large scale maps and charts, those covering a small area, and engineering and architectural drawings, the linear scale can be very simple, a line marked at intervals to show the distance on the earth or object which the distance on the scale represents. A person using the map can use a pair of dividers (or, less precisely, two fingers) to measure a distance by comparing it to the linear scale. The length of the line on the linear scale is equal to the distance represented on the earth multiplied by the map or chart's scale. In most projections, scale varies with latitude, so on small scale maps, covering large areas and a wide range of latitudes, the linear scale must show the scale for the range of latitudes covered by the map. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berardius
The four-toothed whales or giant beaked whales are beaked whales in the genus ''Berardius''. They include Arnoux's beaked whale (''Berardius arnuxii'') in cold Southern Hemispheric waters, and Baird's beaked whale (''Berardius bairdii'') in the cold temperate waters of the North Pacific. A third species, Sato's beaked whale (''Berardius minimus''), was distinguished from ''B. bairdii'' in the 2010s. Arnoux's and Baird's beaked whales are so similar that researchers have debated whether or not they are simply two populations of the same species. However, genetic evidence and their wide geographical separation has led them to be classified as separate. Lifespan estimates, based on earwax plug samples, indicate male whales can live up to 85 years, while females can have a lifespan of 54 years. It is estimated that the length at birth is ~. Growing up to ~, these are the largest whales belonging to the family Ziphiidae. Sato's beaked whale is much smaller, with adult males having ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arnoux's Beaked Whale
Arnoux's beaked whale (''Berardius arnuxii''), also called the southern four-toothed whale, southern beaked whale, New Zealand beaked whale, southern giant bottlenose whale and southern porpoise whale is one of the species of '' Berardius''. Arnoux's and Baird's beaked whales are so similar that researchers have debated whether or not they are simply two populations of the same species, until genetic evidence and their wide geographical separation led them to be classified as separate. Little is known about their behavior due to infrequent encounters with live individuals. Physical description Arnoux's and Baird’s beaked whales, have very similar features and would be indistinguishable at sea if they did not exist in disjoint locations. Both whales reach similar sizes, have bulbous melons, and long prominent beaks. Their lower jaw is longer than the upper, and once sexual maturity is reached the front teeth are visible even when the mouth is fully closed. The Baird's and Arnou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baird's Beaked Whale
Baird's beaked whale (''Berardius bairdii''), also known as the northern giant bottlenose whale, North Pacific bottlenose whale, giant four-toothed whale, northern four-toothed whale and the North Pacific four-toothed whale, is a species of whale from the genus ''Berardius''. Baird's and Arnoux's beaked whales are so similar that researchers have debated whether or not they are simply two populations of the same species. However, genetic evidence and their wide geographical separation has led them to be classified as separate. Baird’s beaked whale is the second largest living species of toothed whale after the sperm whale. Taxonomy Baird's beaked whales were first described in 1883 by American zoologist Leonhard Stejneger based on a skull from a specimen that had been found stranded on the eastern shore of Bering Island the previous fall. The species was named after Spencer Fullerton Baird, the then Secretary of the Smithsonian. A few months after Stejneger's description was pub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MtDNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondrion, mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. This sequencing revealed that the human mtDNA includes 16,569 base pairs and encodes 13 proteins. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and biogeography. Origin Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cookiecutter Shark
The cookiecutter shark (''Isistius brasiliensis''), also called the cigar shark, is a species of small squaliform shark in the family Dalatiidae. This shark occurs in warm, oceanic waters worldwide, particularly near islands, and has been recorded as deep as . It migrates vertically up to every day, approaching the surface at dusk and descending with the dawn. Reaching only in length, the cookiecutter shark has a long, cylindrical body with a short, blunt snout, large eyes, two tiny spineless dorsal fins, and a large caudal fin. It is dark brown, with light-emitting photophores covering its underside except for a dark "collar" around its throat and gill slits. The name "cookiecutter shark" refers to its feeding habit of gouging round plugs, as if cut out with a cookie cutter, out of larger animals. Marks made by cookiecutter sharks have been found on a wide variety of marine mammals and fishes, as well as on submarines, undersea cables, and even human bodies. It also cons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hokkaido
is Japan, Japan's Japanese archipelago, second largest island and comprises the largest and northernmost Prefectures of Japan, prefecture, making up its own List of regions of Japan, region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel. The largest city on Hokkaidō is its capital, Sapporo, which is also its only Cities designated by government ordinance of Japan, ordinance-designated city. Sakhalin lies about 43 kilometers (26 mi) to the north of Hokkaidō, and to the east and northeast are the Kuril Islands, which are administered by Russia, though the four most southerly are Kuril Islands dispute, claimed by Japan. Hokkaidō was formerly known as ''Ezo'', ''Yezo'', ''Yeso'', or ''Yesso''.Louis Frédéric, Nussbaum, Louis-Frédéric. (2005). "Hokkaidō" in Although there were Japanese settlers who ruled the southern tip of the island since the 16th century, Hokkaido was considered foreign territo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Near Threatened
A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify for the threatened status. The IUCN notes the importance of re-evaluating near-threatened taxon at appropriate intervals. The rationale used for near-threatened taxa usually includes the criteria of vulnerable which are plausible or nearly met, such as reduction in numbers or range. Near-threatened species evaluated from 2001 onwards may also be ones which are dependent on conservation efforts to prevent their becoming threatened, whereas before this conservation-dependent species were given a separate category ("Conservation Dependent"). Additionally, the 402 conservation-dependent taxa may also be considered near-threatened. IUCN Categories and Criteria version 2.3 Before 2001, the IUCN used the version 2.3 Categories and Criteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ziphiids
Beaked whales (systematic name Ziphiidae) are a family of cetaceans noted as being one of the least known groups of mammals because of their deep-sea habitat and apparent low abundance. Only three or four of the 24 species are reasonably well-known. Baird's beaked whales and Cuvier's beaked whales were subject to commercial exploitation, off the coast of Japan, while the northern bottlenose whale was extensively hunted in the northern part of the North Atlantic late in the 19th and early 20th centuries. Reports emerged in late 2020 of the possible discovery of a new beaked whale species off the coast of Mexico, the taxonomy of which had not been determined . Physical characteristics Beaked whales are moderate in size, ranging from and weighing from . Their key distinguishing feature is the presence of a 'beak', somewhat similar to many dolphins. Other distinctive features include a pair of converging grooves under the throat, and the absence of a notch in the tail fluke. Alth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
