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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 evolu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleoparadoxiidae
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 Ocean, 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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleoparadoxia BW
''Paleoparadoxia'' ("ancient paradox") is a genus of large, herbivorous aquatic mammals that inhabited the northern Pacific coastal region during the Miocene epoch (). It ranged from the waters of Japan (Tsuyama and Yanagawa), to Alaska in the north, and down to Baja California, Mexico. Description ''Paleoparadoxia'' is thought to have fed primarily on seaweeds and sea grasses. The jaws and the angle of the teeth resemble a backhoe bucket. Its bulky body was well adapted for swimming and underwater foraging. Originally interpreted as amphibious, ''Paleoparadoxia'' is now thought to have been a fully marine mammal like their living relatives, the sirenians, spending most of their lives walking across the sea bottom like marine hippos. Studies on its habitat preference show that it favoured deep, offshore waters. Size estimates of ''P. tabatai'' vary, with the Tsuyama specimen measuring in length, in height, and in body mass, and the other specimens measuring and in body ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleoparadoxia
''Paleoparadoxia'' ("ancient paradox") is a genus of large, herbivorous aquatic mammals that inhabited the northern Pacific coastal region during the Miocene epoch (). It ranged from the waters of Japan (Tsuyama and Yanagawa), to Alaska in the north, and down to Baja California, Mexico. Description ''Paleoparadoxia'' is thought to have fed primarily on seaweeds and sea grasses. The jaws and the angle of the teeth resemble a backhoe bucket. Its bulky body was well adapted for swimming and underwater foraging. Originally interpreted as amphibious, ''Paleoparadoxia'' is now thought to have been a fully marine mammal like their living relatives, the sirenians, spending most of their lives walking across the sea bottom like marine hippos. Studies on its habitat preference show that it favoured deep, offshore waters. Size estimates of ''P. tabatai'' vary, with the Tsuyama specimen measuring in length, in height, and in body mass, and the other specimens measuring and in body m ... [...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] |
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] |
Desmostylidae
Desmostylidae is an extinct family (biology), 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 Annum, 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), Miklós Kretzoi, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paenungulata
Paenungulata (from Latin ''paene'' "almost" + ''ungulātus'' "having hoofs") is a clade of "sub-ungulates", which groups three extant mammal orders: Proboscidea (including elephants), Sirenia (sea cows, including dugongs and manatees), and Hyracoidea ( hyraxes). At least two more possible orders are known only as fossils, namely Embrithopoda and Desmostylia. Molecular evidence indicates that Paenungulata (or at least its extant members) is part of the cohort Afrotheria, an ancient assemblage of mainly African mammals of great diversity. The other members of this cohort are the orders Afrosoricida (tenrecs and golden moles), Macroscelidea (elephant shrews) and Tubulidentata (aardvarks). Of the five orders, hyraxes are the most basal, followed by embrithopods; the remaining orders (sirenians and elephants) are more closely related. These latter three are grouped as the Tethytheria, because it is believed that their common ancestors lived on the shores of the prehistoric Tethys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashoroa
''Ashoroa'' (named after its type locality Ashoro, Hokkaido) is an extinct genus of desmostylian, aquatic, herbivorous mammal. Fossils of ''Ashoroa'' have been found in the Morawan Formation on Hokkaido, Japan (, paleocoordinates ) and were dated to the late Oligocene. Description ''Ashoroa'' is the smallest and one of the oldest desmostylians with an estimated body length of . It is known from a rib, a humerus, a femur, and three vertebrae of the single species and holotype, ''Ashoroa laticosta''. ''Ashoroa'' had pachyosteosclerotic (large and dense) bones. The ribs are broader than in other desmostylians, similar to sirenian ribs, and very dense, like those of '' Behemotops'' and ''Paleoparadoxia''; and extant, semi-aquatic mammals such as Eurasian beaver and hippopotamus, but not as dense as in sirenians. The recovered long bones lack inner cavities, like in ''Paleoparadoxia'' and '' Desmostylus'', and the trabecula A trabecula (plural trabeculae, from Latin for ... [...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] |
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] |
Sirenia
The Sirenia (), commonly referred to as sea-cows or sirenians, are an order of fully aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters. The Sirenia currently comprise two distinct families: Dugongidae (the dugong and the now extinct Steller's sea cow) and Trichechidae (manatees, namely the Amazonian manatee, West Indian manatee, and West African manatee) with a total of four species. The Protosirenidae (Eocene sirenians) and Prorastomidae (terrestrial sirenians) families are extinct. Sirenians are classified in the clade Paenungulata, alongside the elephants and the hyraxes, and evolved in the Eocene 50 million years ago (mya). The Dugongidae diverged from the Trichechidae in the late Eocene or early Oligocene (30–35 mya). Sirenians grow to between in length and in weight. The historic Steller's sea cow was the largest known sirenian to have lived, and could reach lengths of and weights of . Sirenians have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoparadoxia
''Neoparadoxia'' is an extinct genus of large, herbivorous aquatic desmostylian mammals from the Miocene Ladera and Monterey Formation The Monterey Formation is an extensive Miocene oil-rich geological sedimentary formation in California, with outcrops of the formation in parts of the California Coast Ranges, Peninsular Ranges, and on some of California's off-shore islan ...s of North America.Barnes, L.. (2013, September 11) .A new genus and species of late Miocene Paleoparadoxiid (Mammalia, Desmostylia) from California. Natural History Museum of Los Angeles County Contributions in Science, (521), 51–114 References {{Taxonbar, from=Q15636067 Desmostylians Tortonian life Prehistoric placental genera Miocene mammals of North America Paleontology in California Fossil taxa described in 2013 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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