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Megaoryzomys
''Megaoryzomys curioi'', also known as the Galápagos giant rat, is an extinct species of sigmodontine rodent, known only from Santa Cruz Island in the Galápagos Islands. It likely met its demise when European settlers introduced invasive species to the island. It is the only species in the genus ''Megaoryzomys''. Its relationships have historically been unclear; it has been placed in both Oryzomyini Oryzomyini is a tribe of rodents in the subfamily Sigmodontinae of the family Cricetidae. It includes about 120 species in about thirty genera,Weksler et al., 2006, table 1 distributed from the eastern United States to the southernmost parts of ... and Thomasomyini in the past. A 2020 study favoured placing it in the former on overall skull morphology. References * Sigmodontinae Mammals described in 1979 Endemic fauna of the Galápagos Islands Monotypic rodent genera {{Sigmodontinae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigmodontinae
The rodent subfamily Sigmodontinae includes New World rats and mice, with at least 376 species. Many authorities include the Neotominae and Tylomyinae as part of a larger definition of Sigmodontinae. When those genera are included, the species count numbers at least 508. Their distribution includes much of the New World, but the genera are predominantly South American, such as brucies. They invaded South America from Central America as part of the Great American Interchange near the end of the Miocene, about 5 million years ago. Sigmodontines proceeded to diversify explosively in the formerly isolated continent. They inhabit many of the same ecological niches that the Murinae occupy in the Old World. The "Thomasomyini" from the Atlantic Forest of Brazil are generally thought to be not especially related to the "real" Thomasomyini from the northern Andes and the Amazon rainforest. The genera ''Wiedomys'' and '' Sigmodon'' are generally placed in their own tribe, and the "p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oryzomyini
Oryzomyini is a tribe of rodents in the subfamily Sigmodontinae of the family Cricetidae. It includes about 120 species in about thirty genera,Weksler et al., 2006, table 1 distributed from the eastern United States to the southernmost parts of South America, including many offshore islands. It is part of the clade Oryzomyalia, which includes most of the South American Sigmodontinae. The name ''Oryzomyini'' derives from that of its type genus, ''Oryzomys'', which means "rice rat" or "rice mouse". Many species are also known as rice rats. Taxonomy Contents of Oryzomyini An oryzomyine group was first envisaged by Oldfield Thomas in the early 20th century. He defined it to include pentalophodont species, which have a mesoloph(id) on the upper and lower molars, with a long palate (extending past the third molars). Thomas included ''Oligoryzomys'', '' Oecomys'', and ''Oryzomys'' (which included many species now in other genera), as well as ''Rhagomys'', which is currently classi ... [...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, dod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/richochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include Mouse, mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Rabbits, hares, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Cruz Island (Galápagos)
Santa Cruz Island () is one of the Galápagos Islands with an area of and a maximum altitude of . Situated in the center of the archipelago, Santa Cruz is the second largest island after Isabela. Its capital is Puerto Ayora, the most populated urban centre in the islands. On Santa Cruz, there are some small villages, whose inhabitants work in agriculture and cattle raising. The island is an oval-shaped, long and wide shield volcano. Its summit contains a shallow caldera that has been largely buried by youthful pit craters and cinder cones with well-preserved craters. The most recent eruptions may have occurred only a few thousand years ago with the effusion of sparsely vegetated lava flows from vents on the north flank and along the summit fissure. A gigantic lava tube measuring over long is a tourist attraction on the island. As a testimony to its volcanic history there are two big holes formed by the collapse of a magma chamber: Los Gemelos, or "The Twins". Named aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galápagos Islands
The Galápagos Islands ( es, Islas Galápagos) are an archipelago of volcanic islands in the Eastern Pacific, located around the Equator west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of slightly over 33,000 (2020). The province is divided into the Cantons of Ecuador, cantons of San Cristóbal Island, San Cristóbal, Santa Cruz Island (Galápagos), Santa Cruz, and Isabela Island (Galápagos), Isabela, the three most populated islands in the chain. The Galápagos are famous for their large number of Endemism, endemic species, which were studied by Charles Darwin in the 1830s and inception of Darwin's theory, inspired his theory of evolution by means of natural selection. All of these islands are protected as part of Ecuador's Galápagos National Park and Galápagos Marine Reserve, Marine Reserve. Thus far, there is no firm evidence that Polynesian expansion, Polynesians or the indigenous peoples of South Am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammals Described In 1979
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla ( hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla (cetaceans and even-toed ungulates), and the Carnivora ( cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, tog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Fauna Of The Galápagos Islands
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example ''Cytisus aeolicus'' is an endemite of the Italian flora. ''Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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