|
Scimitar-toothed Cat
Homotherini is an extinct tribe (or subtribe) of carnivoran mammals of the family Felidae (true cats). The tribe is commonly known as scimitar-toothed cats. These saber-toothed cats were distributed en North America, Europe, Asia, Africa, and South America from the Miocene to Pleistocene living from c. 23 Ma until c. 12,000 years ago. 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. Evolution Based on mitochondrial DNA sequences extracted from fossils, the lineage of ''Homotherium ''Homotherium'', also known as the scimitar-toothed cat or scimitar cat, is an extinct genus of machairodontine saber-toothed predator, often termed scimitar-toothed cats, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texas Memorial Museum
The Texas Memorial Museum, located on the campus of the University of Texas at Austin in Austin, Texas, USA, was created during preparations for the Texas Centennial Exposition held in 1936. The museum's focus is on natural history, including paleontology, geology, biology, herpetology, ichthyology and entomology. At one point, the museum also had exhibits on Texas history, anthropology, geography, and ethnography, but these were relocated to other museums (including the Bullock Texas State History Museum) in 2001. The building was designed in the Art Deco style by John F. Staub, with Paul Cret as supervising architect. Ground was broken for the building by President Franklin D. Roosevelt in January 1936. The museum was opened on January 15, 1939. The museum won "Best of Austin" awards from the ''Austin Chronicle'' in 2002, 2005, and 2012. In October 2013, Linda Hicke, the dean of Austin's College of Natural Sciences, cut the museum's funding by $400,000 and transferred ownershi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area of , about 30% of Earth's total land area and 8.7% of Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Its 4.7 billion people constitute roughly 60% of the world's population. In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. It is somewhat arbitrary and has moved since its first conception in classical antiquity. The division of Eurasia into two continents reflects East–West cultural, linguistic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Machairodus Giganteus 1
''Machairodus'' (from el, μαχαίρα , 'knife' and el, ὀδούς 'tooth') is a genus of large machairodontine saber-toothed cats that lived in Africa, Eurasia and North America during the late Miocene. It is the animal from which the subfamily Machairodontinae gets its name and has since become a wastebasket taxon over the years as many genera of sabertooth cat have been and are still occasionally lumped into it. Discovery ''Machairodus'' was first named in 1832, by German Naturalist Johann Jakob Kaup. Though its remains had been known since 1824, it was believed by Georges Cuvier that the fossils had come from a species of bear, which he called ''Ursus cultridens'' (known today as ''Megantereon'') based on composite sample of teeth from different countries, species and geologic ages, leading to what would become a long series of complications. Kaup however, recognized the teeth as those of felids and promptly reclassified the existing specimens as ''Machairodus'', incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient DNA
Ancient DNA (aDNA) is DNA isolated from ancient specimens. Due to degradation processes (including cross-linking, deamination and fragmentation) ancient DNA is more degraded in comparison with contemporary genetic material. Even under the best preservation conditions, there is an upper boundary of 0.4–1.5 million years for a sample to contain sufficient DNA for sequencing technologies. The oldest sample ever sequenced is estimated to be 1.65 million years old. Genetic material has been recovered from paleo/archaeological and historical skeletal material, mummified tissues, archival collections of non-frozen medical specimens, preserved plant remains, ice and from permafrost cores, marine and lake sediments and excavation dirt. On 7 December 2022, ''The New York Times'' reported that two-million year old genetic material was found in Greenland, and is currently considered the oldest DNA discovered so far. History of ancient DNA studies 1980s The first study of what would ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. This sequencing revealed that the human mtDNA includes 16,569 base pairs and encodes 13 proteins. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and biogeography. Origin Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being derived ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbourofelis
''Barbourofelis'' is an extinct genus of large, predatory, feliform carnivoran mammals of the family Barbourofelidae (false saber-tooth cats). The genus was endemic to North America and Eurasia during the Miocene until its extinction during the Tortonian, living from 13.6 to 7.3 Ma. Taxonomy ''Barbourofelis'' was named by Bertrand Schultz, Marian Schultz and Larry Martin (1970) in honor of Erwin Hinckley Barbour, who died a few days before the holotype was discovered. Its type is ''Barbourofelis fricki'' and is the type genus of the subfamily Barbourofelinae. It was reassigned to Hoplophoneinae by Flynn and Galiano (1982), then to Barbourofelidae by Bryant (1991), and to Nimravidae by Schultz, et al. (1970) and Martin (1998). Description While the species ''B. fricki'' is thought to have been a lion-sized predator, having a weight comparable to an African lion, with limb bones indicating a muscular, robust body, other species in the genus, such as ''B. morrisi'', are b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megantereon
''Megantereon'' was a genus of prehistoric machairodontine saber-toothed cat that lived in North America, Eurasia, and Africa. It may have been the ancestor of ''Smilodon''. Taxonomy Fossil fragments have been found in Africa, Eurasia, and North America. It also ranged into southernmost China as well, as a mostly complete skull from Sabretooth Cave, Chongzuo indicates, though it seemed to have been rare in most of Asia due to being ill-adapted to closed forest environments. The oldest confirmed records of ''Megantereon'' are known from the Pliocene of North America and are dated to about 4.5 million years. About 3–3.5 million years ago, it is firmly recorded also from Africa (for example, in Kenya), about 2.5 to 2 million years ago also from Asia. In Europe the oldest remains are known from Les Etouaries (France), a site which is now dated to less than 2.5 million years old. Therefore, a North American origin of ''Megantereon'' has been suggested. However, recent findings of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smilodon
''Smilodon'' is a genus of the extinct machairodont subfamily of the felids. It is one of the most famous prehistoric mammals and the best known saber-toothed cat. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats. ''Smilodon'' lived in the Americas during the Pleistocene epoch (2.5 Year#mya, mya – 10,000 years ago). The genus was named in 1842 based on fossils from Brazil; the generic name means "scalpel" or "two-edged knife" combined with "tooth". 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 individuals obtained from the La Brea Tar Pits in Los Angeles constitute the largest collection of ''Smilodon'' fossils. Overall, ''Smilodon'' was more robustly built than any Neontology, extant cat, with particularly well-d ... [...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 endemic to South America, North America, Europe, Asia, and Africa during the Miocene to Pleistocene, from 10.3 mya—11,000 years ago, existing for approximately . 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 varie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annum
A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked. A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars. For the Gregorian calendar, the average length of the calendar year (the mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 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 grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing Great American Interchang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Extinction")
._Walking_with_sabertooths_(fig._1).png "Click for more on -> Barbourofelis")
