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Desmostylidae
Desmostylidae is an extinct family of herbivorous marine mammals belonging to the order of Desmostylia. They lived in the coastal waters of the northern Pacific Ocean from the Early Oligocene (Rupelian) through the Late Miocene (Tortonian) (33.9 mya—7.2 MYA) . Retrieved April 2020.K. Chiba, A. R. Fiorillo, L. L. Jacobs, Y. Kimura, Y. Kobayashi, N. Kohno, Y. Nishida, M. J. Polcyn, and K. Tanaka. 2016. A new desmostylian mammal from Unalaska (USA) and the robust Sanjussen jaw from Hokkaido (Japan), with comments on feeding in derived desmostylids. Historical Biology 28(1-2):289-303 existing for approximately . Taxonomy and systematics Desmostylidae was named by . It was assigned to Sirenia by Osborn (1905); to Proboscidea by Abel (1919); to Desmostyliformes by Simpson (1932), Kretzoi (1941) and Reinhart (1959); to Desmostylia by McKenna and Bell (1997); and to Desmostylia by Carroll (1988), Inuzuka et al. (1995), Inuzuka (2000) and Barnes and Goedert (2001). found a subadult ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornwallius
''Cornwallius'' is an extinct herbivorous marine mammal of the family Desmostylidae. ''Cornwallius'' lived along the North American Pacific Coast from the Early Oligocene ( Chattian) through the Oligocene (28.4 mya—20.6 Mya) and existing for approximately .. Retrieved 16 June 2013. The type locality is the Chattian Sooke Formation, Vancouver Island, British Columbia, Canada (, paleocoordinates ). ''Cornwallius'' was named by . Its type is ''Desmostylus sookensis'', named by and recombined to ''Cornwallius sookensis'' by . Fossils have been discovered from Baja California Peninsula, Oregon and Washington coasts, and Unalaska Island Unalaska ( ale, Nawan-Alaxsxa, russian: Уналашка) is a volcanic island in the Fox Islands group of the Aleutian Islands in the US state of Alaska located at . The island has a land area of . It measures long and wide. The city of Unala .... Notes References * * * * Desmostylians Oligocene mammals Prehistoric placent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Behemotops
''Behemotops'' (from the Biblical monster Behemoth, by Linnaeus and others believed to be a hippo) is an extinct genus of herbivorous marine mammal. It lived from the Early Oligocene (Rupelian) through the Late Oligocene (33.9 mya—23 Mya), existing for approximately . It is the most primitive known desmostylian, believed to be close to the ancestry of all other desmostylians. History of discovery ''B. proteus'' In 1976, Emlong discovered a juvenile mandible — USNM 244035 — on Olympic Peninsula, Clallam County, Washington (, paleocoordinates ) which made the holotype of ''B. proteus''. Teeth of a young adult — LACM 124106 – was found in the same rock unit in 1986. More complete material of ''B. proteus'' was found on Vancouver Island, British Columbia in 2007: the left side of an entire skull with several teeth, a partial scapula, an almost complete humerus, and several ribs and vertebrae. The cranial features of this specimen were s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desmostylians
The Desmostylia (from Greek δεσμά ''desma'', "bundle", and στῦλος ''stylos'', "pillar") are an extinct order of aquatic mammals that existed from the early Oligocene (Rupelian) to the late Miocene (Tortonian) (). Desmostylians are the only known extinct order of marine mammals. The Desmostylia, together with Sirenia and Proboscidea (and possibly Embrithopoda), have traditionally been assigned to the afrotherian clade Tethytheria, a group named after the paleoocean Tethys around which they originally evolved. The relationship between the Desmostylia and the other orders within the Tethytheria has been disputed; if the common ancestor of all tethytheres was semiaquatic, the Proboscidea became secondarily terrestrial; alternatively, the Desmostylia and Sirenia could have evolved independently into aquatic mammals. The assignment of Desmostylia to Afrotheria has always been problematic from a biogeographic standpoint, given that Africa was the locus of the early evo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desmostylia
The Desmostylia (from Greek δεσμά ''desma'', "bundle", and στῦλος ''stylos'', "pillar") are an extinct order of aquatic mammals that existed from the early Oligocene (Rupelian) to the late Miocene (Tortonian) (). Desmostylians are the only known extinct order of marine mammals. The Desmostylia, together with Sirenia and Proboscidea (and possibly Embrithopoda), have traditionally been assigned to the afrotherian clade Tethytheria, a group named after the paleoocean Tethys around which they originally evolved. The relationship between the Desmostylia and the other orders within the Tethytheria has been disputed; if the common ancestor of all tethytheres was semiaquatic, the Proboscidea became secondarily terrestrial; alternatively, the Desmostylia and Sirenia could have evolved independently into aquatic mammals. The assignment of Desmostylia to Afrotheria has always been problematic from a biogeographic standpoint, given that Africa was the locus of the early evoluti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kronokotherium
''Kronokotherium'' is an extinct herbivorous marine mammal of the family Desmostylidae in the order Desmostylia. Its type locality is Raktinskaya, Kamchatka Peninsula, Russia (, paleocoordinates ). ''Kronokotherium'' was made a separate genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ... because the specimen differs from '' Desmostylus'' in the arrangement of the major molar cusps and its smaller size, but it has been synonymized with ''Desmostylus'' by most authors. Notes References * * Desmostylians Miocene mammals of Asia Prehistoric placental genera Fossil taxa described in 1957 Extinct animals of Russia {{Paleo-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desmostylus
''Desmostylus'' is an extinct genus of herbivorous mammal of the family Desmostylidae living from the Chattian stage of the Late Oligocene subepoch through the Late Miocene subepoch (28.4 mya—7.250 Mya) and in existence for approximately .. Retrieved March 2013. Description ''Desmostylus'' was a large, hippopotamus-like creature, with the adult Keton specimen of ''D. hesperus'' measuring in length, in height and in body mass; the largest known humerus which is 1.3 times that of the Keton specimen in length probably belonged to an individual with a mass of . It had a short tail and powerful legs with four hooves. Both the creature's jaws were elongated and sported forward-facing tusks, which were elongated canines and incisors. Most likely fully aquatic, ''Desmostylus'' is thought to have lived in shallow water in coastal regions, usually less than 30 meters deep. Recent isotope work indicates that ''Desmostylus'' more likely lived (or spent a large amount of time) in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Oligocene
The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene Epoch/Series. It spans the time between . It is preceded by the Priabonian Stage (part of the Eocene) and is followed by the Chattian Stage. Name The stage is named after the small river Rupel in Belgium, a tributary to the Scheldt. The Belgian Rupel Group derives its name from the same source. The name Rupelian was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The separation between the group and the stage was made in the second half of the 20th century, when stratigraphers saw the need to distinguish between lithostratigraphic and chronostratigraphic names. Stratigraphic definition The base of the Rupelian Stage (which is also the base of the Oligocene Series) is at the extinction of the foraminiferan genus ''Hantkenina''. An official GSSP for the base of the Rupelian has been assigned in 1992 (Massignano, Italy). The transi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tortonian Extinctions
The Tortonian is in the geologic time scale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma (million years ago). It follows the Serravallian and is followed by the Messinian. The Tortonian roughly overlaps with the regional Pannonian Stage of the Paratethys timescale of Central Europe. It also overlaps the upper Astaracian, Vallesian and lower Turolian European land mammal ages, the upper Clarendonian and lower Hemphillian North American land mammal ages and the upper Chasicoan and lower Huayquerian South American land mammal ages. Definition The Tortonian was introduced by Swiss stratigrapher Karl Mayer-Eymar in 1858. It was named after the Italian city of Tortona in the region Piedmont. The base of the Tortonian Stage is at the last common appearance of calcareous nanoplankton '' Discoaster kugleri'' and planktonic foram '' Globigerinoides subquadratus''. It is also associated with the short normal polarized magnetic c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene Mammals
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the late M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene Mammals
The Oligocene ( ) is a geologic epoch of the Paleogene Period and 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 the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of 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 changes during the Oligocene included a global expansion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afrotheria
Afrotheria ( from Latin ''Afro-'' "of Africa" + ''theria'' "wild beast") is a clade of mammals, the living members of which belong to groups that are either currently living in Africa or of African origin: golden moles, elephant shrews (also known as sengis), tenrecs, aardvarks, hyraxes, elephants, sea cows, and several extinct clades. Most groups of afrotheres share little or no superficial resemblance, and their similarities have only become known in recent times because of genetics and molecular studies. Many afrothere groups are found mostly or exclusively in Africa, reflecting the fact that Africa was an island continent from the Cretaceous until the early Miocene around 20 million years ago, when Afro-Arabia collided with Eurasia. Because Africa was isolated by water, Laurasian groups of mammals such as insectivores, rodents, lagomorphs, carnivorans and ungulates could not reach Africa for much of the early to mid-Cenozoic. Instead, the niches occupied by those groups on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
