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Ground Sloth
Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. They varied widely in size with the largest, belonging to genera '' Lestodon'', ''Eremotherium'' and ''Megatherium'', being around the size of elephants. Ground sloths represent a paraphyletic group, as living tree sloths are thought to have evolved from ground sloth ancestors. The early evolution of ground sloths took place during the late Paleogene and Neogene of South America, while the continent was isolated. At their earliest appearance in the fossil record, they were already distinct at the family level. Sloths dispersed into the Greater Antilles during the Oligocene, and the presence of intervening islands between the American continents in the Miocene allowed a dispersal of some species into North America. They were hardy as evidenced by their high species diversity and their presence in a wide variety of environments, extending from the far south of Patagonia ( Cueva del Milodón ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''Ēṓs'', 'Eos, Dawn') and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch.See: *Letter from William Whewell to Charles Lyell dated 31 January 1831 in: * From p. 55: "The period next antecedent we shall call Eocene, from ήως, aurora, and χαινος, recens, because the extremely small proportion of living species contained in these strata, indicates what may be considered the first commencement, or ''dawn'', of the existing state of the animate creation." 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 isoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenarthra
Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a superorder and major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and armadillos. Extinct xenarthrans include the glyptodonts, pampatheres and ground sloths. Xenarthrans originated in South America during the late Paleocene about 60 million years ago. They evolved and diversified extensively in South America during the continent's long period of isolation in the early to mid Cenozoic Era. They spread to the Antilles by the early Miocene and, starting about 3 million years ago, spread to Central and North America as part of the Great American Interchange. Nearly all of the formerly abundant megafaunal xenarthrans became extinct at the end of the Pleistocene. Characteristics Xenarthrans share several characteristics that are not present in other placental mammals, which suggest that xenarthrans desce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaska
Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the northernmost, westernmost, and easternmost (the Aleutian Islands cross the 180th meridian into the eastern hemisphere) state in the United States. It borders the Canadian territory of Yukon and the province of British Columbia to the east. It shares a western maritime border, in the Bering Strait, with Russia's Chukotka Autonomous Okrug. The Chukchi and Beaufort Seas of the Arctic Ocean lie to the north, and the Pacific Ocean lies to the south. Technically, it is a semi-exclave of the U.S., and is the largest exclave in the world. Alaska is the largest U.S. state by area, comprising more total area than the following three largest states of Texas, California, and Montana combined, and is the seventh-largest subnational division i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cueva Del Milodón Natural Monument
Cueva del Milodón Natural Monument is a Natural Monument located in the Chilean Patagonia, northwest of Puerto Natales and north of Punta Arenas. The monument is situated along the flanks of Cerro Benitez. It comprises several cave Caves or caverns are natural voids under the Earth's Planetary surface, surface. Caves often form by the weathering of rock and often extend deep underground. Exogene caves are smaller openings that extend a relatively short distance undergrou ...s and a rock formation called ''Silla del Diablo'' (Devil's Chair). The monument includes a cave which is notable for the discovery in 1895 of skin, bones and other parts of a ground sloth called '' Mylodon darwini,'' from which the cave takes its name. It is also part of the End of the World Route, a scenic touristic route. Milodón Cave The largest cave in the monument is the long Milodón Cave. It was discovered in 1895 by Hermann Eberhard, German explorer of Patagonia. He found a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patagonia
Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers in the west and Patagonian Desert, deserts, Plateaus, 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 northern limit of the region is not precisely defined; the Colorado River, Argentina, Colorado and Barrancas River, 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 considered part of Patagonia. Most geographers and historians locate the northern limit of Chilean Patagonia at Huincul Fault, in Araucanía R ... [...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] |
Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that 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 Ancient Greek (''olígos'') 'few' and (''kainós'') 'new', and refers to the sparsity of Neontology, extant forms of Mollusca, 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 chang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greater Antilles
The Greater Antilles is a grouping of the larger islands in the Caribbean Sea, including Cuba, Hispaniola, Puerto Rico, and Jamaica, together with Navassa Island and the Cayman Islands. Seven island states share the region of the Greater Antilles, with Haiti and the Dominican Republic sharing the island of Hispaniola. Together with the Lesser Antilles, they make up the Antilles, which along with the Lucayan Archipelago, form the West Indies in the Caribbean region of the Americas. While most of the Greater Antilles consists of independent countries, Puerto Rico and Navassa Island are Territories of the United States, unincorporated territories of the United States, while the Cayman Islands are a British Overseas Territories, British Overseas Territory. The largest island is Cuba, which extends to the western end of the island group. Puerto Rico lies on the eastern end, and the island of Hispaniola, the most populated island, is located in the middle. Jamaica lies to the south of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neogene
The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of the Cenozoic and the eleventh period of the Phanerozoic. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868). The earlier term Tertiary Period was used to define the span of time now covered by Paleogene and Neogene and, despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use. During this period, mammals and birds continued to evolve into modern forms, while other groups of life remained relatively unchanged. The first human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleogene
The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the first period of the Cenozoic Era, the tenth period of the Phanerozoic and is divided into the Paleocene, Eocene, and Oligocene epochs. The earlier term Tertiary Period was used to define the time now covered by the Paleogene Period and subsequent Neogene Period; despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use. Paleogene is often abbreviated "Pg", although the United States Geological Survey uses the abbreviation "" for the Paleogene on the Survey's geologic maps. Much of the world's modern vertebrate diversity originated in a rapid surge of diversification in the early Paleogene, as survivors of the Cretaceous–Paleogene extinction event took advantage of empty ecolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyletic Group
Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic grouping (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term received currency during the debates of the 1960s and 1970s accompanying the rise of cladistics, having been coined by zoologist Willi Hennig to apply to well-known taxa like Reptilia (reptiles), which is paraphyletic with respect to birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor except ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elephants
Elephants are the Largest and heaviest animals, largest living land animals. Three living species are currently recognised: the African bush elephant (''Loxodonta africana''), the African forest elephant (''L. cyclotis''), and the Asian elephant (''Elephas maximus''). They are the only surviving members of the Family (biology), family Elephantidae and the Order (biology), order Proboscidea; extinct relatives include mammoths and mastodons. Distinctive features of elephants include a long proboscis called a trunk, tusks, large ear flaps, pillar-like legs, and tough but sensitive grey skin. The trunk is Prehensility, prehensile, bringing food and water to the mouth and grasping objects. Tusks, which are derived from the incisor teeth, serve both as weapons and as tools for moving objects and digging. The large ear flaps assist in maintaining a constant body temperature as well as in communication. African elephants have larger ears and concave backs, whereas Asian elephants hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
