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Scimitar-toothed Cat
Homotherini (Machairodontini) is a tribe (or subtribe) of saber-toothed cats of the family Felidae (true cats). The tribe is commonly known as scimitar-toothed cats. These saber-toothed cats were endemic to North America, Europe, Asia, Africa, and South America from the Miocene to Pleistocene living from c. 10 Ma until c. 12,000 years ago. The evolutionary relationship between the tribes Homotherini and Machairodontini cause paleontologists to classify Homotherini either as a subtribe of Machairodontini, or the same tribe often using either name interchangeably. Description Compared to the usually massively built dirk-toothed phenotype, apparent in ''Smilodon'', ''Megantereon'' and the feliform '' Barbourofelis'' (just to list a few), their upper canines were smaller than those of equally sized cats of that phenotype, but they had serrated edges. The scimitar-toothed phenotype has also evolved independently in other mammal families. The subtribe Homotherini evolved towards a b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homotherium Serum
''Homotherium'' is an extinct genus of scimitar-toothed cat belonging to the extinct subfamily Machairodontinae that inhabited North America, Eurasia, and Africa, as well as possibly South America during the Pliocene and Pleistocene epochs from around 4 million to 12,000 years ago. It was one of the last surviving members of the subfamily alongside the more famous sabertooth ''Smilodon'', to which it was not particularly closely related. It was a large cat, comparable in size to a lion, functioning as an apex predator in the ecosystems it inhabited. It had an elongate neck and relatively elongate legs, a relatively short back and a very short tail, with the mummy of a ''H. latidens'' cub of Late Pleistocene age found in Siberia having a plain dark brown coat colour. In comparison to ''Smilodon'', the canines of ''Homotherium'' were shorter, though still longer than those of living cats, and it is suggested to have had a different ecology from ''Smilodon'' as a pursuit predator ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the south and west by the Pacific Ocean. The region includes Middle America (Americas), Middle America (comprising the Caribbean, Central America, and Mexico) and Northern America. North America covers an area of about , representing approximately 16.5% of Earth's land area and 4.8% of its total surface area. It is the third-largest continent by size after Asia and Africa, and the list of continents and continental subregions by population, fourth-largest continent by population after Asia, Africa, and Europe. , North America's population was estimated as over 592 million people in list of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrial DNA
Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondrion, mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the DNA contained in a eukaryotic cell; most of the DNA is in the cell nucleus, and, in plants and algae, the DNA also is found in plastids, such as chloroplasts. Mitochondrial DNA is responsible for coding of 13 essential subunits of the complex oxidative phosphorylation (OXPHOS) system which has a role in cellular energy conversion. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. This sequencing revealed that human mtDNA has 16,569 base pairs and encodes 13 proteins. As in other vertebrates, the human mitochondrial genetic code differs slightly from nuclear DNA. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pantherines
The Pantherinae is a subfamily of the Felidae; it was named and first described by Reginald Innes Pocock in 1917 as only including the ''Panthera'' species, but later also came to include the clouded leopards (genus ''Neofelis''). The Pantherinae genetically diverged from a common ancestor between and . Characteristics Pantherinae species are characterised by an imperfectly ossified hyoid bone with elastic tendons that enable their larynx to be mobile. They have a flat rhinarium that only barely reaches the dorsal side of the nose. The area between the nostrils is narrow, and not extended sidewards as in the Felinae. The ''Panthera'' species have a single, rounded, vocal fold with a thick mucosal lining, a large vocalis muscle, and a large cricothyroid muscle with long and narrow membranes. A vocal fold that is longer than enables all but the snow leopard among them to roar, as it has shorter vocal folds of that provide a lower resistance to airflow; this distinction was on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbourofelis
''Barbourofelis'' is an extinct genus of large, predatory, from a subfamily of feliformia, feliform carnivoran mammals of known as Barbourofelidae, Barbourofelinae, part of the Nimravidae superfamily. ''Barbourofelis'', along with ''Albanosmilus'', was the last members barbourofelids, as well as the last nimravids. ''Barbourofelis'' lived North America and Eurasia during the Miocene epoch from 12 to 7 Annum, Ma. Four species are currently recognized within the genus: ''B. fricki'', ''B. loveorum'', ''B. morrisi'', and ''B. piveteaui''. ''B. loveorum'' directly evolved from from ''B. morrisi'', and later evolved into ''B. fricki''. ''B. morrisi'' likely evolved from ''Albanosmilus'' migrating into North America. With ''B. piveteaui'' evolving from reverse migration from North America into Eurasia. ''B. morrisi'' and ''B. piveteaui'' were the smallest species being about as large as a leopard. ''B. loveorum'' was the second largest species and could’ve weighed anywhere from . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megantereon
''Megantereon'' is an extinct genus of prehistoric machairodontine saber-toothed cat that lived in Eurasia, Africa and possibly North America from the late Pliocene to the Middle Pleistocene. It is a member of the tribe Smilodontini, and closely related to and possibly the ancestor of the famous American sabertooth ''Smilodon''. In comparison to ''Smilodon'' it was somewhat smaller, around the size of a jaguar, though it is thought to have had a similar hunting strategy as an ambush predator. Taxonomy and evolution The type species of ''Meganteron'', ''M. cultridens'' was described by Georges Cuvier in 1824, as '' Ursus cultridens'', based on two teeth collected from Pliocene sediments in the Valdarno region of Tuscany, Italy, erroneously considering them to belong to a bear. In addition to the two teeth of ''Megantereon'', Cuvier included another, much older tooth from the late Miocene of Eppelsheim in Germany in the species, which is now known to belong to the unrelated sab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smilodon
''Smilodon'' is an extinct genus of Felidae, felids. It is one of the best known saber-toothed predators and prehistoric mammals. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats, belonging to the extinct subfamily Machairodontinae, with an estimated date of Speciation, divergence from the ancestor of living cats around 20 million years ago. ''Smilodon'' was one of the last surviving machairodonts alongside ''Homotherium''. ''Smilodon'' lived in the Americas during the Pleistocene to early Holocene epoch (2.5 Year#mya, mya – at latest 8,200 years ago). The genus was named in 1842 based on fossils from Brazil; the generic name means or combined with . Three species are recognized today: ''S. gracilis'', ''S. fatalis'', and ''S. populator''. The two latter species were probably descended from ''S. gracilis'', which itself probably evolved from ''Megantereon''. The hundreds of specimens obtained from the La Brea T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smilodontini
Smilodontini is an extinct tribe within the Machairodontinae or "saber-toothed cat" subfamily of the Felidae. The tribe is also known as the "dirk-toothed cats". They were found in South America, North America, Europe, Asia, and Africa during the Middle Miocene to early Holocene, from 10.3 mya—8,200 years ago. As the name suggests, the famous genus of ''Smilodon'' is part of this group, but there are also three other distinct genera in Smilodontini. The earliest known genus of the tribe is '' Promegantereon'', once thought to be a species of '' Paramachairodus''. The tribe only became extinct 10,000 years ago, with the demise of ''Smilodon''. All of these are saber-toothed cats, meaning that they have long, narrow upper canines and stocky, well muscled proportions. Description The various members of Smilodontini are generally distinguished by their long, narrow upper canines. However, the stockiness often seen as one of the tribe's signature features varied between the differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annum
A year is a unit of time based on how long it takes the Earth to orbit the Sun. In scientific use, the tropical year (approximately 365 solar days, 5 hours, 48 minutes, 45 seconds) and the sidereal year (about 20 minutes longer) are more exact. The modern calendar year, as reckoned according to the Gregorian calendar, approximates the tropical year by using a system of leap years. The term 'year' is also used to indicate other periods of roughly similar duration, such as the lunar year (a roughly 354-day cycle of twelve of the Moon's phasessee lunar calendar), as well as periods loosely associated with the calendar or astronomical year, such as the seasonal year, the fiscal year, the academic year, etc. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by changes in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek () 'most' and (; Latinized as ) 'new'. The aridification and cooling trends of the preceding Neogene were continued in the Pleistocene. The climate was strongly variable depending on the glacial cycle, oscillating between cold Glacial period, glacial periods and warmer Interglacial, int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first epoch (geology), 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 followed the Oligocene and preceded 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 distinct global events but by regionally defined transitions from the warmer Oligocene to the cooler Pliocene Epoch. During the Early Miocene, Afro-Arabia collided with Eurasia, severing the connection between the Mediterranean and Indian Oceans, and allowing the interchange of fauna between Eurasia and Africa, including the dispersal of proboscideans and Ape, hominoids into Eurasia. During the late Miocene, the conn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion of the Americas. South America is bordered on the west by the Pacific Ocean, on the north and east by the Atlantic Ocean, and to the south by the Drake Passage; North America and the Caribbean Sea lie to the northwest. The continent includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territory, dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one administrative division, internal territory: French Guiana. The Dutch Caribbean ABC islands (Leeward Antilles), ABC islands (Aruba, Bonaire, and Curaçao) and Trinidad and Tobago are geologically located on the South-American continental shel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
