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Proborhyaena Gigantea
''Proborhyaena'' is an extinct genus of proborhyaenid sparassodont that lived during the Oligocene of what is now South America. It is considered to be the largest of the sparassodonts. Description This animal was very large in size, with the skull alone reaching up to 40 centimeters long, and the whole animal may have been as large as a present-day grizzly bear. It is speculated that ''Proborhyaena'' may have weighed up to . It was a massive animal, with a robust and powerful body. Its skull was equipped with a short, high snout, and its caniniform teeth were saber-shaped, although not as developed as those of the later ''Thylacosmilus''. The canines, in contrast to those of ''Thylacosmilus'' which had an "almond-shaped" section and a sharp margin, were ovoid in cross-section and thus must have been much more robust. Like the thylacosmilids, ''Proborhyaena'' possessed only one pair of lower incisors. Classification ''Proborhyaena'' was first described by Florentino Ameghino in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major changes during the Oligocene included a global expansion o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uruguay
Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering the Río de la Plata to the south and the Atlantic Ocean to the southeast. It is part of the Southern Cone region of South America. Uruguay covers an area of approximately and has a population of an estimated 3.4 million, of whom around 2 million live in the metropolitan area of its capital and largest city, Montevideo. The area that became Uruguay was first inhabited by groups of hunter–gatherers 13,000 years ago. The predominant tribe at the moment of the arrival of Europeans was the Charrúa people, when the Portuguese first established Colónia do Sacramento in 1680; Uruguay was colonized by Europeans late relative to neighboring countries. The Spanish founded Montevideo as a military stronghold in the early 18th century bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene Mammals Of South America
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major changes during the Oligocene included a global expansion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sparassodonts
Sparassodonta (from Greek to tear, rend; and , gen. , ' tooth) is an extinct order of carnivorous metatherian mammals native to South America, related to modern marsupials. They were once considered to be true marsupials, but are now thought to be a separate side branch that split before the last common ancestor of all modern marsupials. A number of these mammalian predators closely resemble placental predators that evolved separately on other continents, and are cited frequently as examples of convergent evolution. They were first described by Florentino Ameghino, from fossils found in the Santa Cruz beds of Patagonia. Sparassodonts were present throughout South America's long period of "splendid isolation" during the Cenozoic; during this time, they shared the niches for large warm-blooded predators with the flightless terror birds. Previously, it was thought that these mammals died out in the face of competition from "more competitive" placental carnivorans during the Pli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ungulates
Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, camels, sheep, deer, and hippopotamuses. Cetaceans such as whales, dolphins, and porpoises are also classified as even-toed ungulates, although they do not have hooves. Most terrestrial ungulates use the hoofed tips of their toes to support their body weight while standing or moving. The term means, roughly, "being hoofed" or "hoofed animal". As a descriptive term, "ungulate" normally excludes cetaceans as they do not possess most of the typical morphological characteristics of other ungulates, but recent discoveries indicate that they were also descended from early artiodactyls. Ungulates are typically herbivorous and many employ specialized gut bacteria to allow them to digest cellulose. Some modern species, such as pigs, are omnivorous, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrotherium
''Pyrotherium'' ('fire beast') is an extinct genus of South American ungulate, of the order Pyrotheria, that lived in what is now Argentina and Bolivia, during the Late Oligocene.''Pyrotherium'' at .org It was named ''Pyrotherium'' because the first specimens were excavated from an ancient volcanic ash deposit. Fossils of the genus have been found in the and s of Argentina and the |
Carnivorous
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other soft tissues) whether through hunting or scavenging. Nomenclature Mammal order The technical term for mammals in the order Carnivora is ''carnivoran'', and they are so-named because most member species in the group have a carnivorous diet, but the similarity of the name of the order and the name of the diet causes confusion. Many but not all carnivorans are meat eaters; a few, such as the large and small cats (felidae) are ''obligate'' carnivores (see below). Other classes of carnivore are highly variable. The Ursids, for example: While the Arctic polar bear eats meat almost exclusively (more than 90% of its diet is meat), almost all other bear species are omnivorous, and one species, the giant panda, is nearly exclusively herbivorous. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecological Niches
In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of resources and competitors (for example, by growing when resources are abundant, and when predators, parasites and pathogens are scarce) and how it in turn alters those same factors (for example, limiting access to resources by other organisms, acting as a food source for predators and a consumer of prey). "The type and number of variables comprising the dimensions of an environmental niche vary from one species to another ndthe relative importance of particular environmental variables for a species may vary according to the geographic and biotic contexts". See also Chapter 2: Concepts of niches, pp. 7 ''ff'' A Grinnellian niche is determined by the habitat in which a species lives and its accompanying behavioral adaptations. An Eltonian niche emphasizes that a spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupials
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a pouch. Marsupials include opossums, Tasmanian devils, kangaroos, koalas, wombats, wallabies, bandicoots, and the extinct thylacine. Marsupials represent the clade originating from the last common ancestor of extant metatherians, the group containing all mammals more closely related to marsupials than to placentals. They give birth to relatively undeveloped young that often reside in a pouch located on their mothers' abdomen for a certain amount of time. Close to 70% of the 334 extant species occur on the Australian continent (the mainland, Tasmania, New Guinea and nearby islands). The remaining 30% are found in the Americas—primarily in South America, thirteen in Central America, and one species, the Virginia opossum, in North America, nor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arminiheringia
''Arminiheringia'' is an extinct genus of sparassodont. It lived during the Early Eocene in South America. Description This animal had an exceptionally robust skull with strong teeth. The lower canines were exceptionally long and projected forward. The molars and premolars suggests a carnivorous diet. Its body was probably massive, and the animal reached a considerable size, about 1.8 meters in length. Its legs were strong and sturdy, with a general appearance probably resembling that of a modern bear. Classification ''Arminiheringia'' was a typical member of the family Proborhyaenidae, a clade of South American bear-like metatherians. Those animals belonged to the order Sparassodonta, a clade related to marsupials whose members, during the course of their evolution, occupied niches ordinarily occupied on other continents by carnivores. Arminiheringia and its relatives superficially resembled creodont Creodonta ("meat teeth") is a former order of extinct carnivorous placent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callistoe
''Callistoe'' is an extinct genus of sparassodont. It lived during the Early Eocene, and its fossilized remains were found in South America. Description Unlike most of its relatives, such as '' Proborhyaena'' and ''Arminiheringia'', ''Callistoe'' had a narrow, puny snout, and the shape of its skull resembled that of a thylacine. ''Callistoe'' lacked the characteristics associated with the ability to climb in its limbs and vertebrae. The shape of its limb joints, the presence of an ossified patella and the shape of the limb bones show that it was limited to a parasagittal gait, and possessed little flexibility in its elbows, wrists, knees and ankles ; ''Callistoe'' probably specialized in walking and running. ''Callistoe'', approximately two meters long, had a slender and light body, and weighed approximately 23 kilograms. Classification ''Callistoe vincei'' was first described in 2002, based on an almost complete and exceptionally preserved skeleton from the Lumbrera Formation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proborhyaenidae
Proborhyaenidae is an extinct family of metatherian mammals of the order Sparassodonta, which lived in South America from the Eocene (Mustersan) until the Oligocene (Deseadan). Sometimes it has been included as a subfamily of their relatives, the borhyaenids (as Proborhyaeninae). The largest species, ''Proborhyaena gigantea'', is estimated to be about the size of a spectacled bear, with its skull reaching in length, and body mass estimates up to approximately , making the proborhyaenids some of the largest known metatherians. Proborhyaenid remains have been found in western Bolivia, Uruguay, southern Brazil, and the provinces of Mendoza, Salta, and Chubut, in Argentina. Most proborhyaenids had a robust, hyena-like skull, although one species, ''Callistoe vincei'', had an elongate, narrow skull more reminiscent of a thylacine. The teeth were strongly specialized as carnassials for eating meat, and in '' Arminiheringia'' rotated throughout the animal's life to maintain a continu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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