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Caenolestid
The family Caenolestidae contains the seven surviving species of shrew opossum: small, shrew-like marsupials that are confined to the Andes mountains of South America. The order is thought to have diverged from the ancestral marsupial line very early. They were once included in the superorder but it is now known that Ameridelphia is paraphyletic, having given rise to Australidelphia, and thus could be considered an evolutionary grade. Genetic studies indicate that they are the second most basal order of marsupials, after the didelphimorphs. As recently as 20 million years ago, at least seven genera were in South America. Today, just three genera remain. They live in inaccessible forest and grassland regions of the High Andes. Shrews were entirely absent from South America until the Great American Interchange three million years ago, and are currently present only in the northwestern part of the continent. Traditionally, it was thought that shrew opossums lost ground to these a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhyncholestes
The long-nosed caenolestid (''Rhyncholestes raphanurus''), also known as the Chilean shrew opossum or long-nosed shrew opossum, is a shrew opossum that occurs in temperate forests of Argentina and southern Chile. It was first described by American zoologist Wilfred Hudson Osgood in 1924. The long-nosed caenolestid resembles ''Caenolestes'' species in morphology. It is characterized by a long, pointed snout, small eyes and ears, and one claw on a digit of each of the thin limbs. Little is known of its behavior; it appears to be terrestrial (lives on land), nocturnal (active mainly at night) and omnivorous. It prefers cool, moist areas, and has a small distribution. It is classified as near threatened by the IUCN. Taxonomy and etymology The long-nosed caenolestid is the sole member of its genus, and is classified in the family Caenolestidae. It was first described by American zoologist Wilfred Hudson Osgood in 1924. Two subspecies are recognised: *''R. r. continentalis'' Bublitz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caenolestes Sangay
The eastern caenolestid (''Caenolestes sangay'') is a shrew opossum found on the eastern slopes of the Andes in southern Ecuador. Etymology The origin of the genus name (''Caenolestes'') drives from the Greek words ''kainos'' ("new") and ''lestes'' ("robber", "pirate"). The origin of the species name (''sangay'') derives from Sangay National Park, which is the largest Andean national park in Ecuador. The park itself is named after a volcano called Sangay, one of Ecuador's most active volcanoes that lies within the park. Sangay National Park was the site of the discovery of the eastern caenolestid in 2010. Taxonomy The eastern caenolestid is one of the five members of ''Caenolestes'', and is placed in the family Caenolestidae (shrew opossums). In the latter part of 20th century, scientists believed that ''Caenolestes'' is closely related to ''Lestoros'' (the Incan caenolestid). Over the years, it became clear that ''Lestoros'' is morphologically different from ''Caenolestes''. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caenolestes
The common shrew opossums (genus ''Caenolestes'') are members of the family Caenolestidae. They are found in Colombia, Ecuador, Peru, and Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th .... The most recently discovered species is ''C. sangay''. References Shrew opossums Marsupials of South America Marsupial genera Neogene mammals of South America Quaternary mammals of South America Taxa named by Oldfield Thomas Prehistory of Ecuador Prehistory of Peru Prehistory of Venezuela {{marsupial-stub ... [...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] |
Insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. Their blood is not totally contained in vessels; some circulates in an open cavity known as the haemocoel. Insects are the most diverse group of animals; they include more than a million described species and represent more than half of all known living organisms. The total number of extant species is estimated at between six and ten million; In: potentially over 90% of the animal life forms on Earth are insects. Insects may be found in nearly all environments, although only a small number of species reside in the oceans, which are dominated by another arthropod group, crustaceans, which recent research has indicated insects are nested within. Nearly all insects hatch from eggs. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monodelphis
''Monodelphis'' is a genus of marsupials in the family Didelphidae, commonly referred to as short-tailed opossums. They are found throughout South America. , the most recently described species is ''M. vossi''. Species * Sepia short-tailed opossum (''Monodelphis adusta'') * Northern three-striped opossum (''Monodelphis americana'') * Arlindo's short-tailed opossum (''Monodelphis arlindoi'') * Northern red-sided opossum (''Monodelphis brevicaudata'') * Yellow-sided opossum (''Monodelphis dimidiata'') * Gray short-tailed opossum (''Monodelphis domestica'') * Emilia's short-tailed opossum (''Monodelphis emiliae'') * Gardner's short-tailed opossum (''Monodelphis gardneri'') * Amazonian red-sided opossum (''Monodelphis glirina'') * Ihering's three-striped opossum (''Monodelphis iheringi'') * Pygmy short-tailed opossum (''Monodelphis kunsi'') * Marajó short-tailed opossum (''Monodelphis maraxina'') * Osgood's short-tailed opossum (''Monodelphis osgoodi'') * Hooded red-sided ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecological Niche
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] |
Eutheria
Eutheria (; from Greek , 'good, right' and , 'beast'; ) is the clade consisting of all therian mammals that are more closely related to placentals than to marsupials. Eutherians are distinguished from noneutherians by various phenotypic traits of the feet, ankles, jaws and teeth. All extant eutherians lack epipubic bones, which are present in all other living mammals (marsupials and monotremes). This allows for expansion of the abdomen during pregnancy. The oldest-known eutherian species is '' Juramaia sinensis'', dated at from the early Late Jurassic ( Oxfordian) of China. Eutheria was named in 1872 by Theodore Gill; in 1880 Thomas Henry Huxley defined it to encompass a more broadly defined group than Placentalia. Characteristics Distinguishing features are: *an enlarged malleolus ("little hammer") at the bottom of the tibia, the larger of the two shin bones *the joint between the first metatarsal bone and the entocuneiform bone (the innermost of the three cuneiform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southern subregion of a single continent called America. South America is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest. The continent generally includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one internal territory: French Guiana. In addition, the ABC islands of the Kingdom of the Netherlands, Ascension Island (dependency of Saint Helena, Ascension and Tristan da Cunha, a British Overseas Territory), Bouvet Island ( dependency of Norway), Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PLoS Biology
''PLOS Biology'' is a monthly peer-reviewed scientific journal covering all aspects of biology. Publication began on October 13, 2003. It is the first journal published by the Public Library of Science. The editor-in-chief is Nonia Pariente. In addition to research articles, the journal publishes magazine content aimed to be accessible to a broad audience. Article types in this section are essays, "unsolved mysteries", editorials, and synopses. Abstracting and indexing The journal is abstracted and indexed in: *Biological Abstracts *BIOSIS Previews *''Current Contents''/Agriculture, Biology & Environmental Sciences *''Current Contents''/Life Sciences *Chemical Abstracts Service * Embase *''Index Medicus''/MEDLINE/PubMed *Science Citation Index *Scopus *''The Zoological Record'' According to ''Journal Citation Reports'', the journal had a 2019 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clariv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Didelphimorph
Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 93 species in 18 genera. Opossums originated in South America and entered North America in the Great American Interchange following the connection of North and South America. The Virginia opossum is the only species found in the United States and Canada. It is often simply referred to as an opossum, and in North America it is commonly referred to as a possum (; sometimes rendered as ''possum'' in written form to indicate the dropped "o"). Possums should not be confused with the Australasian arboreal marsupials of suborder Phalangeriformes that are also called possums because of their resemblance to the Didelphimorphia. The opossum is typically a nonaggressive animal. Etymology The word ''opossum'' is borrowed from the Powhatan language and was first recorded between 1607 and 1611 by John Smith (as ''opassom'') an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal (phylogenetics)
In phylogenetics, basal is the direction of the ''base'' (or root) of a phylogenetic tree#Rooted tree, rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa. While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank, Phylogenetic diversity, species diversity, or both. If ''C'' is a basal clade within ''D'' that has the lowest rank of all basal clades within ''D'', ''C'' may be described as ''the'' basal taxon of that rank within ''D''. The concept of a 'key innovation' implies some degree of correlation between evolutionary innovation and cladogenesis, diversification. However, such a correlation does not make a given ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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