The Zebra is an example of a quadruped.

Quadrupedalism (from Latin, meaning "four legs") is a form of land animal locomotion using four legs. The majority of walking animals are quadrupeds, including mammals such as cattle and cats, and reptiles, like lizards. Birds, humans, insects, crustaceans, and snakes are not quadrupeds. Image File history File linksMetadata Download high resolution version (1005x699, 121 KB) Summary By me. ... Image File history File linksMetadata Download high resolution version (1005x699, 121 KB) Summary By me. ... Species Equus zebra Equus quagga Equus hartmannae Equus grevyi Zebras (members of the horse family), are native to central and southern Africa. ... A number of animals have evolved so as to be able to travel over the ground. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Orders Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Eutheria (excludes extinct ancestors) Afrosoricida Anagaloidea (extinct) Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Dinocerata (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Litopterna (extinct) Macroscelidea Mesonychia (extinct) Notoungulata (extinct) Perissodactyla Pholidota Plesiadapiformes... Binomial name Bos taurus Linnaeus, 1758 Cattle (called cows in vernacular usage, kine archaic, or kye as the Scots plural of cou) are domesticated ungulates, a member of the subfamily Bovinae of the family Bovidae. ... Look up CAT in Wiktionary, the free dictionary. ... Orders See text. ... Families Many, see text. ... Orders Many - see section below. ... Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin for wise man or knowing man) under the family Hominidae (the great apes). ... Classes & Orders See taxonomy Insects are invertebrate animals of the Class Insecta, the largest and (on land) most widely-distributed taxon within the phylum Arthropoda. ... Classes & Subclasses Branchiopoda Phyllopoda Sarsostraca Remipedia Cephalocarida Maxillopoda Thecostraca Tantulocarida Branchiura Pentastomida Mystacocarida Copepoda Ostracoda Myodocopa Podocopa Malacostraca Phyllocarida Hoplocarida Eumalacostraca The crustaceans (Crustacea) are a large group of arthropods (55,000 species), usually treated as a subphylum [1]. They include organisms such as lobsters, crabs, shrimp and barnacles. ... Superfamilies and Families Snakes (from Old English snaca, and ultimately from the Proto-Indo-European base snag- or sneg-, to crawl), also known as ophidians, are cold blooded legless reptiles closely related to lizards, which share the order Squamata. ...

Quadrupeds and tetrapods

Not all four-limbed animals are quadrupeds. Although arms and wings are, in the evolutionary sense, modified legs, four-limbed animals are in fact classed as tetrapods – members of the taxonomic unit Tetrapoda. These include all vertebrates with quadrupedal ancestors, including mammals, reptiles, amphibians, and birds. Groups See text. ... Linnaean taxonomy classifies living things into a hierarchy, originally starting with kingdoms. ... Classes Synapsida Sauropsida Amphibia A tetrapod (Greek tetrapoda, four-legged) is a vertebrate animal having four feet, legs or leglike appendages. ... Classes and Clades Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. ... Orders Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Eutheria (excludes extinct ancestors) Afrosoricida Anagaloidea (extinct) Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Dinocerata (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Litopterna (extinct) Macroscelidea Mesonychia (extinct) Notoungulata (extinct) Perissodactyla Pholidota Plesiadapiformes... Orders See text. ... For other uses, see Amphibian (disambiguation). ... Orders Many - see section below. ...

The distinction between quadrupeds and tetrapods is important in evolutionary biology, particularly in the context of bipeds, winged animals, and animals whose limbs have adapted to other roles (e.g. fins, in the case of cetaceans and pinnipeds). All of these animals are tetrapods, but none are quadrupeds. Even snakes, whose limbs have become entirely vestigial, are nevertheless tetrapods. This article or section does not cite its references or sources. ... A fin is a surface used to produce lift and thrust or to steer while traveling in water, air, or other fluid media. ... Suborders Mysticeti Odontoceti (see text) The order Cetacea includes whales, dolphins and porpoises. ... Families Odobenidae Otariidae Phocidae Pinnipeds (fin-feet, lit. ... Superfamilies and Families Snakes (from Old English snaca, and ultimately from the Proto-Indo-European base snag- or sneg-, to crawl), also known as ophidians, are cold blooded legless reptiles closely related to lizards, which share the order Squamata. ... The human vermiform appendix is a vestigial structure: it no longer retains its original function. ...

Quadrupedalism in humans

In July of 2005, in rural Turkey, scientists discovered five Kurdish siblings who had learned to walk naturally on their hands and feet. Unlike chimpanzees, who ambulate on their knuckles, the Turkish siblings (ranging from 18 to 34 years old) walked on their palms, allowing them to preserve the dexterity of their fingers. Calluses found on their hands make the possibility of a hoax unlikely. Another similar case has been reported in Chile, but the case is still being investigated and reports are not released as of March 22, 2006. 2005 (MMV) was a common year starting on Saturday of the Gregorian calendar. ... Kurds are one of the Iranian peoples and speak Kurdish, a north-Western Iranian language related to Persian. ... Type Species Simia troglodytes Blumenbach, 1775 Species Pan troglodytes Pan paniscus Chimpanzee, often shortened to chimp, is the common name for the two extant species in the genus Pan. ... Gorillas knuckle-walk using both their legs and their long arms (putting pressure on their knuckles, with the fingers rolled into the hand). ... The Family That Walks On All Fours is a BBC2 telefilm documenting the case of a family of mentally disabled individuals in Turkey who reportedly locomote in a quadrupedal fashion. ... 2006 (MMVI) is a common year starting on Sunday of the Gregorian calendar. ...

The discovery of the family has provided scientists a unique view into human evolutionary history. Nicholas Humphrey, a researcher from the London School of Economics, has suggested that the siblings' gait is an instinctive human behavior which has simply been abandoned over the course of evolution. Humphrey argues that the five siblings, who suffer from mental retardation doi doi related to cerebellar ataxia, have regressed to an earlier stage of human evolution, and have simply continued to walk "as infants" into adulthood. The London School of Economics and Political Science, often referred to as the London School of Economics or simply the LSE, is a specialist university and a constituent college of the federal University of London, located on Houghton Street in Central London, off the Aldwych and next to the Royal... Cerebellum (in blue) of the human brain Spinocerebellar ataxia (SCA) is a genetic disease with multiple types, each of which could be considered a disease in its own right. ...

Other scientists, such as Stefan Mundlos of the Max Planck Institute, believe that the family's unusual gait may result from a genetic abnormality. Mundlos has isolated a gene on chromosome 17 which is responsible for human bipedalism. He speculates that the Turkish siblings lack this gene. The Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. ... Chromosome 17 is one of the 23 pairs of chromosomes in humans. ... This article or section does not cite its references or sources. ...