A genus is a taxonomic rank used in the biological classification of living and fossil organisms, as well as viruses, in biology. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.
Biodiversity is the variety and variability of life on Earth. Biodiversity is typically a measure of variation at the genetic, species, and ecosystem level. Terrestrial biodiversity is usually greater near the equator, which is the result of the warm climate and high primary productivity. Biodiversity is not distributed evenly on Earth, and is richest in the tropics. These tropical forest ecosystems cover less than 10 percent of earth's surface, and contain about 90 percent of the world's species. Marine biodiversity is usually highest along coasts in the Western Pacific, where sea surface temperature is highest, and in the mid-latitudinal band in all oceans. There are latitudinal gradients in species diversity. Biodiversity generally tends to cluster in hotspots, and has been increasing through time, but will be likely to slow in the future.
In biology, extinction is the termination of an organism or of a group of organisms (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" after a period of apparent absence.
The IUCN Red List of Threatened Species, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit.
The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. The word cephalothorax is derived from the Greek words for head and thorax. This fusion of the head and thorax is seen in chelicerates and crustaceans; in other groups, such as the Hexapoda, the head remains free of the thorax. In horseshoe crabs and many crustaceans, a hard shell called the carapace covers the cephalothorax.
The conservation status of a group of organisms indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation status: not simply the number of individuals remaining, but the overall increase or decrease in the population over time, breeding success rates, and known threats. Various systems of conservation status exist and are in use at international, multi-country, national and local levels as well as for consumer use.
Sicarius is a genus of spider in the family Sicariidae. In 2017, the genus Hexophthalma was split off from Sicarius; as currently circumscribed, Sicarius is native to South America with one species found in Central America. Sicarius is one of three genera in the family Sicariidae. The venom of its species appears to be less dangerous than that of species of the other two genera, Hexophthalma and Loxosceles.
The Harpactirinae are a subfamily of tarantulas which are native to the continent of Africa. Like many Old World tarantulas, they have a relatively strong venom, and can inflict a painful bite.
Ceratogyrus is a genus of tarantulas found in southern Africa. They are commonly called horned baboons for the foveal horn found on the peltidium in some species. They are readily distinguished from other African theraphosid genera by the combined presence of a retrolateral cheliceral scopula, composed of plumose, stridulatory setae, and the strongly procurved fovea. The fovea is typically strongly procurved and in some species surrounds a distinct protuberance. this protuberance may take the form of a simple posterior extension of the caput, a low-set plug or a prominent, discrete conical projection. All Ceratogyrus species possess a pale yellow anteriorly placed, transverse, sub-abdominal band. This feature is not distinct in other Harpatirinae except Augacephalus junodi. The absence of dense, ventral femoral fringes on the palpi and legs I and II distinguish Ceratogyrus spp. from female A. junodi.
Ceratogyrus darlingi is a theraphosid spider from southern Africa, mainly Botswana and Lesotho. They reach a body length of about 5 inches (130 mm) and are ash-gray, mud-brown to black. The peltidium features a black foveal horn.
Ceratogyrus brachycephalus is an old world terrestrial tarantula that grows to a legspan of up to 5 inches (12 cm). The common name comes from the "horn", or protuberance, on the carapace.
An endangered species is a species which has been categorized as very likely to become extinct in the near future. Endangered (EN), as categorized by the International Union for Conservation of Nature (IUCN) Red List, is the second most severe conservation status for wild populations in the IUCN's schema after Critically Endangered (CR). In 2012, the IUCN Red List featured 3,079 animal and 2,655 plant species as endangered (EN) worldwide. The figures for 1998 were 1,102 and 1,197 respectively. Many nations have laws that protect conservation-reliant species: for example, forbidding hunting, restricting land development or creating protected areas. Population numbers, trends and species' conservation status can be found at the lists of organisms by population.
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined.
Augacephalus is a genus of harpacterine theraphosid spiders. It has three species, all of which are found in Africa.
Ernest Edward Williams was an American herpetologist. He coined the term ecomorph based on his research on anoles.
Enicoscolus is a genus of March flies (Bibionidae).
Ceratogyrus meridionalis, commonly known as the Zimbabwe grey baboon tarantula or the grey mustard baboon, is a species of tarantula. It is found in Malawi and Mozambique.
