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Palaeoamasia
''Palaeoamasia'' is an extinct herbivorous paenungulate mammal of the embrithopod order, making it distantly related to elephants, sirenians, and hyraxes. ''Palaeoamasia'' fossils have been found in Turkish deposits of the Çeltek Formation, dating to the Ypresian. It has unique bilophodont upper molars, an embrithopod synapomorphy. Discovery ''Palaeoamasia kansui'' (Ozansoy, 1966), the type species, was first discovered in Anatolia, Turkey in 1966. Since then, ''Palaeoamasia'' fossils have only been found In Anatolia. The fossil record of ''Palaeoamasia'' is scarce, although a new species of ''Palaeoamasia'' was discovered in 2014. The ''Palaeoamasia'' sp. nov. fossil is the youngest found to date, extending the period of survival of the genus to the early Oligocene. The fossils recorded consist mostly of tooth and jaw fragments. The tooth fossils show that ''Palaeoamasia'' has two prominent transverse crests on upper molars, signifying the embrithopod synapomorphy of bilophod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embrithopoda
Embrithopoda ("heavy-footed") is an order of extinct mammals known from Asia, Africa and Eastern Europe. Most of the embrithopod genera are known exclusively from jaws and teeth dated from the late Paleocene to the late Eocene; however, the order is best known from its terminal member, the elephantine ''Arsinoitherium''. Description While embrithopods bore a superficial resemblance to rhinoceroses, their horns had bony cores covered in keratinized skin. Not all embrithopods possessed horns, either. Despite their appearance, they have been regarded as related to elephants, not perissodactyls. As tethytheres, the Embrithopoda have been believed to be part of the clade Afrotheria. However, a study of the basal arsinoitheriid, ''Palaeoamasia'', suggests that embrithopods are not tethytheres or even paenungulates, and that they need to be better sampled in an analysis of eutherian relationships to clarify if they are even afrotherians.[Erdal et al.'s inclusion of Embrithopoda in ... [...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 Sea; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arsinoitherium
''Arsinoitherium'' is an extinct genus of paenungulate mammals belonging to the extinct order Embrithopoda. It is related to elephants, sirenians, hyraxes and the extinct desmostylians. Arsinoitheres were superficially rhinoceros-like herbivores that lived during the Late Eocene and the Early Oligocene of North Africa from 36 to 30 million years ago, in areas of tropical rainforest and at the margin of mangrove swamps. A species described in 2004, ''A. giganteum'', lived in Ethiopia about 27 million years ago. Taxonomy The best-known (and first-described) species is ''A. zitteli''. Another species, ''A. giganteum'', was discovered in the Ethiopian highlands of Chilga in 2003. The fossil teeth, far larger than those of ''A. zitteli'', date to around 28–27 million years ago. While the Fayum Oasis is the only site where complete skeletons of ''Arsinoitherium'' fossils were recovered, arsinoitheriids have been found in southeastern Europe, including ''Crivadiatherium'' from Romani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ypresian
In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian is consistent with the lower Eocene. Events The Ypresian Age begins during the throes of the Paleocene–Eocene Thermal Maximum (PETM). The Fur Formation in Denmark, the Messel shales in Germany, the Oise amber of France and Cambay amber of India are of this age. The Eocene Okanagan Highlands are an uplands subtropical to temperate series of lakes from the Ypresian. Stratigraphic definition The Ypresian Stage was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The Ypresian is named after the Flemish city of Ypres in Belgium (spelled ''Ieper'' in Dutch). The definitions of the original stage were totally different from the modern ones. The Ypresian shares its name with the Belgian Ieper Group (French: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pontides
The Pontic Mountains or Pontic Alps ( Turkish: ''Kuzey Anadolu Dağları'', meaning North Anatolian Mountains) form a mountain range in northern Anatolia, Turkey. They are also known as the ''Parhar Mountains'' in the local Turkish and Pontic Greek languages. The term ''Parhar'' originates from a Hittite word meaning "high" or "summit". In ancient Greek, the mountains were called the Paryadres or Parihedri Mountains. Geography The range runs roughly east–west, parallel and close to the southern coast of the Black Sea. It extends northeast into Georgia, and west into the Sea of Marmara, with the northwestern spur of the Küre Mountains (and their western extension the Akçakoca Mountains) and the Bolu Mountains, following the coast. The highest peak in the range is Kaçkar Dağı, which rises to . The North Anatolian Fault and the Northeast Anatolian Fault, which are east–west-running strike-slip faults, run along the length of the range. Ecology The mountains are gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene Mammals Of Asia
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Placental Genera
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ypresian Life
In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian is consistent with the lower Eocene. Events The Ypresian Age begins during the throes of the Paleocene–Eocene Thermal Maximum (PETM). The Fur Formation in Denmark, the Messel shales in Germany, the Oise amber of France and Cambay amber of India are of this age. The Eocene Okanagan Highlands are an uplands subtropical to temperate series of lakes from the Ypresian. Stratigraphic definition The Ypresian Stage was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The Ypresian is named after the Flemish city of Ypres in Belgium (spelled ''Ieper'' in Dutch). The definitions of the original stage were totally different from the modern ones. The Ypresian shares its name with the Belgian Ieper Group (Fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plantigrade
151px, Portion of a human skeleton, showing plantigrade habit In terrestrial animals, plantigrade locomotion means walking with the toes and metatarsals flat on the ground. It is one of three forms of locomotion adopted by terrestrial mammals. The other options are digitigrade, walking on the toes with the heel and wrist permanently raised, and unguligrade, walking on the nail or nails of the toes (the hoof) with the heel/wrist and the digits permanently raised. The leg of a plantigrade mammal includes the bones of the upper leg (femur/humerus) and lower leg (tibia and fibula/radius and ulna). The leg of a digitigrade mammal also includes the metatarsals/metacarpals, the bones that in a human compose the arch of the foot and the palm of the hand. The leg of an unguligrade mammal also includes the phalanges, the finger and toe bones. Among extinct animals, most early mammals such as pantodonts were plantigrade. A plantigrade foot is the primitive condition for mammals; di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paratethys
The Paratethys sea, Paratethys ocean, Paratethys realm or just Paratethys was a large shallow inland sea that stretched from the region north of the Alps over Central Europe to the Aral Sea in Central Asia. Paratethys was peculiar due to its paleogeography: it consisted of a series of deep basins, formed during the Oxfordian stage of the Late Jurassic as an extension of the rift that formed the Central Atlantic Ocean. These basins were connected with each other and the global ocean by narrow and shallow seaways that often limited water exchange and caused widespread long-term anoxia. Paratethys was at times reconnected with the Tethys or its successors (the Mediterranean Sea or the Indian Ocean) during the Oligocene and the early and middle Miocene times, but at the onset of the late Miocene epoch, the tectonically trapped sea turned into a megalake from the eastern Alps to what is now Kazakhstan. From the Pliocene epoch onward (after 5 million years ago), Paratethys b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vicariance
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow. Various geographic changes can arise such as the movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations. These factors can substantially alter a region's geography, resulting in the separation of a species population into isolated subpopulations. The vicariant populations then undergo genetic changes as they become subjected to different selective pressures, experience genetic drift, and accumulate different mutations in the separated populations' gene pools. The barriers prevent the exchange of genetic information between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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