|
Coryphodontoidea
Coryphodontidae is an extinct family of pantodont mammals known from the Late Paleocene to the Middle Eocene of Eurasia and North America. The type genus ''Coryphodon'' is known from around the Paleocene-Eocene transition in Europe, western United States, northern Canada, and eastern Asia. The remaining genera are known exclusively from the middle Eocene of Asia. The coryphodontids are related to the pantolambdids. ''Coryphodon'' are large, derived pantodonts first described in the mid-19th century, but no intermediate stages leading to their unusual upper molars are known. The last known species of ''Coryphodon'' have bilophodont The molars or molar teeth are large, flat tooth, teeth at the back of the mouth. They are more developed in mammal, mammals. They are used primarily to comminution, grind food during mastication, chewing. The name ''molar'' derives from Latin, ... molars similar to later, more derived coryphodontids, and, most likely, ''Coryphodon'' is the prim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pantodonta
Pantodonta is an extinct suborder (or, according to some, an order) of eutherian mammals. These herbivorous mammals were one of the first groups of large mammals to evolve (around 66 million years ago) after the end of the Cretaceous. The last pantodonts died out at the end of the Eocene (around 34 million years ago). Pantodonta include some of the largest mammals of their time, but were a diversified group, with some primitive members weighing less than and the largest more than . The earliest and most primitive pantodonts, ''Bemalambda'' (with a skull probably the size of a dog) and '' Hypsilolambda'', appear in the early Paleocene Shanghuan Formation in China. All more derived families are collectively classified as Eupantodonta. The pantodonts appear in North America in the middle Paleocene, where '' Coryphodon'' survived into the middle Eocene. Pantodont teeth have been found in South America (''Alcidedorbignya'') and Antarctica, and footprints in a coal mine on Svalb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pantodonts
Pantodonta is an extinct suborder (or, according to some, an order) of eutherian mammals. These herbivorous mammals were one of the first groups of large mammals to evolve (around 66 million years ago) after the end of the Cretaceous. The last pantodonts died out at the end of the Eocene (around 34 million years ago). Pantodonta include some of the largest mammals of their time, but were a diversified group, with some primitive members weighing less than and the largest more than . The earliest and most primitive pantodonts, '' Bemalambda'' (with a skull probably the size of a dog) and '' Hypsilolambda'', appear in the early Paleocene Shanghuan Formation in China. All more derived families are collectively classified as Eupantodonta. The pantodonts appear in North America in the middle Paleocene, where ''Coryphodon'' survived into the middle Eocene. Pantodont teeth have been found in South America (''Alcidedorbignya'') and Antarctica, and footprints in a coal mine on S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Eocene
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 o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleocene First Appearances
The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''palaiós'' meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by an asteroid impact and possibly volcanism, marked the beginning of the Paleocene and killed off 75% of living species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification. In the Paleocene, the continents of the Northern Hemisphere were still connected via s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygyny
Polygyny (; from Neoclassical Greek πολυγυνία (); ) is the most common and accepted form of polygamy around the world, entailing the marriage of a man with several women. Incidence Polygyny is more widespread in Africa than in any other continent. Some scholars see the slave trade's impact on the male-to-female sex ratio as a key factor in the emergence and fortification of polygynous practices in regions of Africa. Polygyny is most common in a region known as the "polygamy belt" in West Africa and Central Africa, with the countries estimated to have the highest polygamy prevalence in the world being Burkina Faso, Mali, Gambia, Niger and Nigeria. In the region of sub-Saharan Africa, polygyny is common and deeply rooted in the culture, with 11% of the population of sub-Saharan Africa living in such marriages (25% of the Muslim population and 3% of the Christian population, as of 2019). Polygyny is especially widespread in West Africa, with the countries estimated t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molar (tooth)
The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone tooth", from ''mola'', millstone and ''dens'', tooth. Molars show a great deal of diversity in size and shape across mammal groups. The third molar of humans is sometimes vestigial. Human anatomy In humans, the molar teeth have either four or five cusps. Adult humans have 12 molars, in four groups of three at the back of the mouth. The third, rearmost molar in each group is called a wisdom tooth. It is the last tooth to appear, breaking through the front of the gum at about the age of 20, although this varies from individual to individual. Race can also affect the age at which this occurs, with statistical variations between groups. In some cases, it may not even erupt at all. The human mouth contains upper (maxillary) and lower (mandib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gobiatherium Major
''Gobiatherium'' (meaning "Beast of the Gobi Desert") was one of the last Uintatheres, from the Mid Eocene of Mongolia. Unlike its North American cousins, ''Uintatherium'' or ''Eobasileus ''Eobasileus cornutus'' ("horned dawn-king") was a prehistoric species of dinocerate mammal. Description About long, and standing some tall at the shoulder, with a weight estimated to be around , ''Eobasilius'' was the largest uintathere ...'', ''Gobiatherium'' lacked knob-like horns, or even fang-like tusks. Instead, it had enlarged cheekbones and an almost spherical snout. Because of the noticeable lack of many diagnostic uintathere features (the horns and tusks), the genus is placed within its own subfamily, "Gobiatheriinae", though some experts prefer to rank it as the family "Gobiatheriidae". References *Cheng Jie & Ma Aneheng: ''New mammalian materials from the Eocene of the Liguanqiao basin.'' Vertebrata PalAsiatica 28, 1990, S. 228–244. * McKenna, M.C. & Bell, S.K. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Paleocene
The Thanetian is, in the ICS Geologic timescale, the latest age or uppermost stratigraphic stage of the Paleocene Epoch or Series. It spans the time between . The Thanetian is preceded by the Selandian Age and followed by the Ypresian Age (part of the Eocene). The Thanetian is sometimes referred to as the Late Paleocene. Stratigraphic definition The Thanetian was established by Swiss geologist Eugène Renevier in 1873. The Thanetian is named after the Thanet Formation, the oldest Cenozoic deposit of the London Basin, which was first identified in the area of Kent (southern England) known as the Isle of Thanet. The base of the Thanetian Stage is laid at the base of magnetic chronozone C26n. The references profile (Global Boundary Stratotype Section and Point) is in the Zumaia section (43° 18'N, 2° 16'W) at the beach of Itzurun, Pais Vasco, northern Spain. Fossils of the unicellular planktonic marine coccolithophore '' Areoligeria gippingensis'' make their first appeara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coryphodon
''Coryphodon'' (from Greek κορῦφὴ, "point", and ὀδοὺς, "tooth", meaning ''peaked tooth'', referring to "the development of the angles of the ridges into points n the molars") is an extinct genus of pantodonts of the family Coryphodontidae. ''Coryphodon'' was a pantodont, a member of the world's first group of large browsing mammals. It migrated across what is now northern North America, replacing ''Barylambda'', an earlier pantodont. It is regarded as the ancestor of the genus '' Hypercoryphodon'' of Late Eocene Mongolia. ''Coryphodon'' is known from many specimens in North America and considerably fewer in Europe, Mongolia, and China. It is a small to medium-sized coryphodontid who differs from other members of the family in dental characteristics. Description At about at shoulder height and in body length, ''Coryphodon'' is one of the largest-known mammals of its time. The creature was very slow, with long upper limbs and short lower limbs, which were neede ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
