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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] |
Great American Interchange
The Great American Biotic Interchange (commonly abbreviated as GABI), also known as the Great American Interchange and the Great American Faunal Interchange, was an important late Cenozoic paleozoogeographic biotic interchange event in which land and freshwater fauna migrated from North America via Central America to South America and vice versa, as the volcanic Isthmus of Panama rose up from the sea floor and bridged the formerly separated continents. Although earlier dispersals had occurred, probably over water, the migration accelerated dramatically about 2.7 million years ( Ma) ago during the Piacenzian age. It resulted in the joining of the Neotropic (roughly South American) and Nearctic (roughly North American) biogeographic realms definitively to form the Americas. The interchange is visible from observation of both biostratigraphy and nature (neontology). Its most dramatic effect is on the zoogeography of mammals, but it also gave an opportunity for reptiles, amphibia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupial
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, n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hondadelphidae
''Hondadelphys'' is an extinct genus of carnivorous sparassodonts, known from the Middle Miocene of Colombia. The type species, ''H. fieldsi'', was described in 1976 from the fossil locality of La Venta, which hosts fossils from the Villavieja Formation. ''Hondadelphys ''was originally interpreted as belonging to the opossum family Didelphidae, but subsequently assigned to its own family, Hondadelphidae and interpreted as a basal sparassodont. The genus name refers to the Honda Group, the stratigraphic group in which the fossils of this animal were first found, combined with ''delphys ''(Greek for "womb", a common suffix used for opossum-like metatherian Metatheria is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. First proposed by Thomas Henry Huxley in 1880, it is a more inclusive group than the marsupials; it contains all marsupials as well ...s). References Sparassodonts Miocene mammals of South America Lave ... [...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] |
Borhyaenidae
Borhyaenidae is an extinct metatherian family of low-slung, heavily built predatory mammals in the order Sparassodonta. Borhyaenids are not true marsupials, but members of a sister taxon, Sparassodonta. Like most metatherians, borhyaenids and other sparassodonts are thought to have had a pouch to carry their offspring around. Borhyaenids had strong and powerful jaws, like those of the unrelated placentalians ''Hyaenodon'' and ''Andrewsarchus'', for crushing bones. Borhyaenids grew up to an average of long. ''Borhyaena'' is the type genus of this group. Originally, the borhyaenids were one of the most diverse groups of sparassodonts, including all species not originally included in the Thylacosmilidae. However, in recent years, with the elevation of most sparassodont subfamilies to family rank and the discovery that borhyaenids are more closely related to proborhyaenids and thylacosmilids than other sparassodonts, the family has been reduced to seven species in four genera. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thylacosmilidae
Thylacosmilidae is an extinct Family (biology), family of metatherian predators, related to the modern marsupials, which lived in South America between the Miocene and Pliocene epochs. Like other South American mammalian predators that lived prior to the Great American Biotic Interchange, these animals belonged to the order Sparassodonta, which occupied the ecological niche of many eutherian mammals of the order Carnivora from other continents. The family's most notable feature are the elongated, laterally flattened fangs, which is a remarkable evolutionary convergence with other saber-toothed mammals like ''Barbourofelis'' and ''Smilodon''. Taxonomic history The family Thylacosmilidae was originally erected by Riggs in 1933, to accommodate ''Thylacosmilus'', found in the Pliocene Brochero Formation of Argentina. Later, the family was demoted to a subfamily, as Thylacosmilinae, within Borhyaenidae, a group of superficially canid-like sparassodonts, under the assumption that '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lycopsis
''Lycopsis'' is an extinct genus of South American metatherian, that lived during the Miocene in Argentina and Colombia. History Although not named until 1927, Florentino Ameghino described a species now seen as synonymous with ''Lycopsis torresi'', ''Anatherium oxyrhynchus'', in 1895 based on a mandibular ramus with several teeth.Marshall, L. G. (1977). A new species of Lycopsis (Borhyaenidae: Marsupialia) from the La Venta fauna (Late Miocene) of Colombia, South America. ''Journal of Paleontology'', 633-642. The fossil was recovered from Puesto Estancia La Costa in Santa Cruz, Argentina, dating to the Miocene. The type material of ''Lycopsis'' was collected in July 1895 by "C. Berry" from the middle Miocene strata of the Santa Cruz Formation along the Santa Cruz River in the same area.Cabrera, Á. (1927). Datos para el conocimiento de los dasiuroideos fósiles argentinos. ''Revista del Museo de la Plata'', ''30'', 271-315. The fossils (MLP 11-113) were fragmentary, constitu ... [...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] |
Marten
A marten is a weasel-like mammal in the genus ''Martes'' within the subfamily Guloninae, in the family Mustelidae. They have bushy tails and large paws with partially retractile claws. The fur varies from yellowish to dark brown, depending on the species; it is valued by animal trappers for the fur trade. Martens are slender, agile animals, adapted to living in the taiga, which inhabit coniferous and northern deciduous forests across the Northern Hemisphere. Classification Results of DNA research indicate that the genus ''Martes'' is paraphyletic, with some studies placing ''Martes americana'' outside the genus and allying it with ''Eira'' and ''Gulo'', to form a new New World clade. The genus first evolved up to seven million years ago during the Miocene epoch. Fossils Several fossil martens have been described, including: *†''Martes campestris'' (Pliocene) *†''Martes wenzensis'' (Pliocene) *†''Martes vetus'' (Pleistocene) Another described fossil species, ''Martes n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patagonia
Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and glaciers in the west and deserts, tablelands and steppes to the east. Patagonia is bounded by the Pacific Ocean on the west, the Atlantic Ocean to the east, and many bodies of water that connect them, such as the Strait of Magellan, the Beagle Channel, and the Drake Passage to the south. The Colorado and Barrancas rivers, which run from the Andes to the Atlantic, are commonly considered the northern limit of Argentine Patagonia. The archipelago of Tierra del Fuego is sometimes included as part of Patagonia. Most geographers and historians locate the northern limit of Chilean Patagonia at Huincul Fault, in Araucanía Region.Manuel Enrique Schilling; Richard WalterCarlson; AndrésTassara; Rommulo Vieira Conceição; Gustavo Walter Bertotto; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omnivore
An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutrients and energy of the sources absorbed. Often, they have the ability to incorporate food sources such as algae, fungi, and bacteria into their diet. Omnivores come from diverse backgrounds that often independently evolved sophisticated consumption capabilities. For instance, dogs evolved from primarily carnivorous organisms ( Carnivora) while pigs evolved from primarily herbivorous organisms (Artiodactyla). Despite this, physical characteristics such as tooth morphology may be reliable indicators of diet in mammals, with such morphological adaptation having been observed in bears. The variety of different animals that are classified as omnivores can be placed into further sub-categories depending on their feeding behaviors. Frugivor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first 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 is preceded by the Oligocene and is followed by 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 a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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