Context: Threatened species are any species (including animals, plants, fungi, etc.) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of "critical depensation", a mathematical measure of biomass related to population growth rate. This quantitative metric is one method of evaluating the degree of endangerment. , Neochoerus ( `` new hog '' ) is an extinct genus of rodent closely related to the living capybara ., A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant, or other type of organism. The term typically refers to the zone in which the organism lives and where it can find food, shelter, protection and mates for reproduction. It is the natural environment in which an organism lives, or the physical environment that surrounds a species population., The capybara ("Hydrochoerus hydrochaeris") is the largest rodent in the world. It is a member of the genus "Hydrochoerus", of which the only other extant member is the lesser capybara ("Hydrochoerus isthmius"). Close relatives are guinea pigs and rock cavies, and it is more distantly related to the agouti, chinchillas, and the coypu. Native to South America, the capybara inhabits savannas and dense forests and lives near bodies of water. It is a highly social species and can be found in groups as large as 100 individuals, but usually lives in groups of 1020 individuals. The capybara is not a threatened species and is hunted for its meat and hide and also for a grease from its thick fatty skin which is used in the pharmaceutical trade., The coypu (; "Myocastor coypus"), also known as the river rat or nutria, is a large, omnivorous, semiaquatic rodent and the only member of the family Myocastoridae. Originally native to subtropical and temperate South America, it has since been introduced to North America, Europe, Asia, and Africa, primarily by fur ranchers. Although it is still valued for its fur in some regions, its destructive feeding and burrowing behaviors make this invasive species a pest throughout most of its range., Rodents (from Latin "rodere", "to gnaw") are mammals of the 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 found in vast numbers on all continents except Antarctica. They are the most diversified mammalian order and live in a variety of terrestrial habitats, including human-made environments., Mammals are any vertebrates within the class Mammalia (from Latin "mamma" "breast"), a clade of endothermic amniotes distinguished from reptiles and birds by the possession of a neocortex (a region of the brain), hair, three middle ear bones and mammary glands. The sister group of mammals may be the extinct "Haldanodon." The mammals represent the only living Synapsida, which together with the Sauropsida form the Amniota clade. The mammals consist of the Yinotheria including monotrema and the Theriiformes including the theria., Chinchillas are two species of crepuscular rodents, slightly larger and more robust than ground squirrels. They are native to the Andes mountains in South America and live in colonies called "herds" at high elevations up to . Historically, chinchillas lived in an area that included parts of Bolivia, Peru, Argentina, and Chile, but today colonies in the wild are known only in Chile. Along with their relatives, viscachas, they make up the family Chinchillidae., The lesser capybara ("Hydrochoerus isthmius") is a large semiaquatic rodent of the family Caviidae found in eastern Panama, northwestern Colombia and western Venezuela. It was recognized as a distinct subspecies of capybara in 1912, and was elevated to species status in 1991. It breeds year-round, with an average litter size of 3.5. Individuals may be diurnal or nocturnal and solitary or social depending on season, habitat and hunting pressure. This species is reported to be common in Panama but rare in Venezuela. It is threatened by subsistence hunting, the destruction of gallery forests and swamp drainage, specifically the swamp drainage of the Magdalena River. Its karyotype has 2n = 64 and FN = 104., The guinea pig ("Cavia porcellus"), cavy or domestic guinea pig, or cuy for livestock breeds, is a species of rodent belonging to the family Caviidae and the genus "Cavia". Despite their common name, these animals are not in the pig family Suidae, nor do they come from Guinea. They originated in the Andes, and earlier studies based on biochemistry and hybridization suggest they are domesticated descendants of a closely related species of cavy such as "Cavia aperea", "C. fulgida", or "C. tschudii" and, therefore, do not exist naturally in the wild. Recent studies applying molecular markers, in addition to studying the skull and skeletal morphology of current and mummified animals, revealed that the ancestor is most likely "Cavia tschudii"., Skin is the soft outer covering of vertebrates. Other animal coverings, such as the arthropod exoskeleton have different developmental origin, structure and chemical composition. The adjective cutaneous means "of the skin" (from Latin "cutis", skin). In mammals, the skin is an organ of the integumentary system made up of multiple layers of ectodermal tissue, and guards the underlying muscles, bones, ligaments and internal organs. Skin of a different nature exists in amphibians, reptiles, and birds. All mammals have some hair on their skin, even marine mammals like whales, dolphins, and porpoises which appear to be hairless.
The skin interfaces with the environment and is the first line of defense from external factors. For example, the skin plays a key role in protecting the body against pathogens and excessive water loss. Its other functions are insulation, temperature regulation, sensation, and the production of vitamin D folates. Severely damaged skin may heal by forming scar tissue. This is sometimes discoloured and depigmented. The thickness of skin also varies from location to location on an organism. In humans for example, the skin located under the eyes and around the eyelids is the thinnest skin in the body at 0.5 mm thick, and is one of the first areas to show signs of aging such as "crows feet" and wrinkles. The skin on the palms and the soles of the feet is 4 mm thick and the back is 14 mm thick and is the thickest skin in the body. The speed and quality of wound healing in skin is promoted by the reception of estrogen., Subject: neochoerus, Relation: parent_taxon, Options: (A) animal (B) area (C) areas (D) cavia (E) caviidae (F) fungi (G) hydrochoerus (H) mammal (I) myocastor (J) pig (K) plant (L) rat (M) rodentia (N) sauropsida (O) theria (P) theriiformes
Output: caviidae