|
Ashorocetus
''Ashorocetus'' is a monotypic genus of an extinct primitive baleen whale of the family Aetiocetidae. It was named by , and contains one species, ''A. eguchii''. Fossils of this whale are found from the Chattian Morawan formation, near Ashoro, of upper Oligocene () Hokkaido, Japan (, paleocoordinates ). ''Ashorocetus eguchii'' was described based on a partial skull and is named after the type locality and Kenichiro Eguchi of the Ashoro Museum of Paleontology. Description described four new aetiocetid species, of whom ''Ashorocetus eguchii'' was the most primitive. It has a neatly telescoped skull and is closely related to ''Chonecetus'', another primitive aetiocetid. Barnes et al. also described '' Morawanocetus yabukii'', a more derived species with a foreshortened braincase, intermediate between ''Chonecetus'' and ''Aetiocetus''; ''Aetiocetus tomitai'', the most primitive ''Aetiocetus'' discovered; and ''Aetiocetus polydentatus'', the most derived ''Aetiocetus'' with a hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aetiocetus
''Aetiocetus'' is a genus of extinct basal mysticete, or baleen whale that lived , in the Oligocene in the North Pacific ocean, around Japan, Mexico, and Oregon, U.S. It was first described by Douglas Emlong in 1966 and currently contains known four species, ''A. cotylalveus'', ''A. polydentatus'', ''A. tomitai'', and ''A. weltoni''. These whales are remarkable for their retention of teeth and presence of nutrient foramina, indicating that they possessed baleen. Thus, ''Aetiocetus'' represents the transition from teeth to baleen in Oligocene mysticetes. Baleen is a highly derived character, or synapomorphy, of mysticetes, and is a keratinous structure that grows from the palate, or roof of the mouth, of the whale. The presence of baleen is inferred from the fossil record in the skull of ''Aetiocetus''. ''Aetiocetus'' is known from both sides of the Pacific Ocean: it was first documented in Oregon, United States, but it is also known from Japan and Mexico. The genus is curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baleen Whale
Baleen whales (), also known as whalebone whales, are marine mammals of the order (biology), parvorder Mysticeti in the infraorder Cetacea (whales, dolphins and porpoises), which use baleen plates (or "whalebone") in their mouths to sieve plankton from the water. Mysticeti comprises the family (biology), families Balaenidae (right whale, right and Bowhead whale, bowhead whales), Balaenopteridae (rorquals), Eschrichtiidae (the gray whale) and Cetotheriidae (the pygmy right whale). There are currently 16 species of baleen whales. While cetaceans were historically thought to have descended from Mesonychia, mesonychians, molecular phylogenetics, molecular evidence instead supports them as a clade of even-toed ungulates (Artiodactyla). Baleen whales split from toothed whales (Odontoceti) around 34 mya (unit), million years ago. Baleen whales range in size from the and pygmy right whale to the and blue whale, the Largest organisms, largest known animal to have ever existed. They ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aetiocetidae
Aetiocetidae is an extinct Family (biology), family of toothed Baleen whale, baleen whales known from the Oligocene and latest Eocene, so far only from rocks deposited in the North Pacific Ocean. The whales ranged in size from long. Many of the described specimens were discovered from the Upper Oligocene of the Japanese Morawan Formation, the largest known one from the Morawan's Upper tuffaceous siltstone. Other formally described extinct toothed mysticetis from this time are smaller, from in length. Mysticeti with true baleen are seen in fossils from the Upper Oligocene. The monophyly of the family is still uncertain, as are the evolutionary relationship between the early toothed baleen whales (Aetiocetidae, Mammalodontidae, and Llanocetidae) and the early and extant Edentulism, edentulous baleen whales. However, the cladistic analyses of ''Coronodon'' and ''Mystacodon'' seem to indicate that Aetiocetidae and Llanocetidae are more closely related to crown Mysticeti than to Mamma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morawanocetus
''Morawanocetus'' is a genus of extinct primitive baleen whale from the family Aetiocetidae that existed during the Chattian stage of the Oligocene epoch. Its fossils have been found in the North Pacific. ''Morawanocetus'' was named by Barnes ''et al.'' in 1995, who described the species, ''M. yabukii''. Three new species, dating from 17 to 19 million years ago, were unearthed between 2000 and 2005 in a road-widening project in California. These three new specimens of ''Morawanocetus'', a genus thought to have gone extinct some five million years earlier, were discovered next to a fourth specimen, still under preparation, which clearly has archaeocete dentition.. CSUF. Retrieved 11 January 2014. ''Morawanocetus'' was divergent, with wide crania, elaborate cheek, tooth crowns, and short necks. The first fossils of ''Morawanocetus'' were found in the Chattian-aged Morawan Formation of Upper Oligocene Hokkaido. The more recent findings are the first ''Morawanocetus'' fossils f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chonecetus
''Chonecetus'' is an extinct genus of primitive baleen whale of the family Aetiocetidae that lived in the Oligocene period. Its fossils have been found in Canada, in the northeast Pacific. It was first named by L.S. Russell in 1968, and contains one species, ''C. sookensis''. Like ''Aetiocetus'', ''Chonecetus'' possessed both multicusped teeth and the nutrient foramina required for baleen.''Marine Mammals: Evolutionary Biology''; page 62. By Annalisa Berta, James L. Sumich, and Kit M. Kovacs, published 2005; Academic Press. Retrieved on July 1, 2008. ''Chonecetus'' closely resembled a modern Mysticeti, with an elongate, streamlined body supporting a pair of paddle-shaped forelimbs, and a horizontal tail fluke strengthened by fibrous cartilage. Sister Taxa *''Aetiocetus'' *''Ashorocetus'' *''Fucaia'' *''Morawanocetus ''Morawanocetus'' is a genus of extinct primitive baleen whale from the family Aetiocetidae that existed during the Chattian stage of the Oligocene epoch. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willungacetus
''Willungacetus'' is an extinct genus of primitive baleen whale of the family Aetiocetidae known from the Oligocene of Australia (at Port Willunga, , paleocoordinates ). It is the oldest-known whale from Australia, and the only aetiocetid whale currently known from the Southern Hemisphere. Neville S. Pledge first visited the type locality in 1983 and collected two boulders. These two rocks, however, were forgotten until 2001 when a partial vertebra were discovered within. The site was subsequently revisited and another specimen, a partial cranium, was discovered. Pledge referred a radius, collected from the same cliff in 1994, to his newly named species. Pledge provisionally assigned ''Willungacetus'' to Aetiocetidae, but this assignment still needs to be confirmed. Sister taxa *''Aetiocetus'' *''Ashorocetus'' *''Chonecetus'' *''Morawanocetus ''Morawanocetus'' is a genus of extinct primitive baleen whale from the family Aetiocetidae that existed during the Chattian stage o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from Ancient Greek (''olígos'') 'few' and (''kainós'') 'new', and refers to the sparsity of Neontology, extant forms of Mollusca, molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major chang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Species
In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological Type (biology), type wiktionary:en:specimen, specimen (or specimens). Article 67.1 A similar concept is used for suprageneric groups and called a type genus. In botanical nomenclature, these terms have no formal standing under the International Code of Nomenclature for algae, fungi, and plants, code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus name is a specimen (or, rarely, an illustration) which is also the type of a species name. The species name with that type can also be referred to as the type of the genus name. Names of genus and family ranks, the various subdivisions of those ranks, and some higher-rank names based on genus names, have suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family (, : ) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". The delineation of what constitutes a family—or whether a described family should be acknowledged—is established and decided upon by active taxonomists. There are not strict regulations for outlining or acknowledging a family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to a lack of widespread consensus within the scientific community ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chattian
The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage of the Miocene). Stratigraphic definition The Chattian was introduced by Austrian palaeontologist Theodor Fuchs in 1894. Fuchs named the stage after the Chatti, a Germanic tribe.Berry, Edward W"The Mayence Basin, a Chapter of Geologic History" ''The Scientific Monthly'', Vol. 16, No. 2, February 1923. pp. 114. Retrieved March 18, 2020. The original type locality was near the German city of Kassel. The base of the Chattian is at the extinction of the foram genus ''Chiloguembelina'' (which is also the base of foram biozone P21b). An official GSSP for the Chattian Stage was ratified in October of 2016. The top of the Chattian Stage (which is the base of the Aquitanian Stage, Miocene Series and Neogene System) is at the first appeara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashoro
is a town located in Tokachi Subprefecture, Hokkaido, Japan. As of September 2016, the town has an estimated population of 7,150 and a density of 5.1 persons per km2. The total area is 1,408.09 km2. It was the largest municipality in Japan until the merger of Takayama City, Gifu Prefecture on February 1, 2005. Main industries of the town include dairying and farming of sugar beet and wheat. Lake Onnetō is a major attraction of the town and is a part of Akan National Park. Geography Ashoro is located in the northeastern part of Tokachi Subprefecture. Kushiro and Shiranuka are to the east and to the south are Honebestu and Obihiro. Kamishiro is to the west and to the north is Oketo, Rikubestu and Tsubetsu. Ashoro consists of rolling foothills and is nestled at the base of Mount Meakan. Ashoro-gun is 66.5 km wide and 48.2 km long and is 1,408.09K m2. Ashoro is considered a wide town. 83 percent of the town's land is forested.Town of Ashoro Outline 2011 Climate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hokkaido
is the list of islands of Japan by area, second-largest island of Japan 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 railway via the Seikan Tunnel. The largest city on Hokkaido is its capital, Sapporo, which is also its only cities designated by government ordinance of Japan, ordinance-designated city. Sakhalin lies about 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. The position of the island on the northern end of the archipelago results in a colder climate, with the island seeing significant snowfall each winter. Despite the harsher climate, it serves as an agricultural breadbasket for many crops. Hokkaido was formerly known as ''Ezo'', ''Yezo'', ''Yeso'', or ''Yes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
