Amphibians are ectothermic, anamniotic, four-limbed vertebrate animals that constitute the class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all tetrapods excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds and mammals). All extant (living) amphibians belong to the monophyletic subclass Lissamphibia, with three living orders: Anura (frogs and toads), Urodela (salamanders), and Gymnophiona (caecilians). Evolved to be mostly semiaquatic, amphibians have adapted to inhabit a wide variety of habitats, with most species living in freshwater, wetland or terrestrial ecosystems (such as riparian woodland, fossorial and even arboreal habitats). Their life cycle typically starts out as aquatic larvae with gills known as tadpoles, but some species have developed behavioural adaptations to bypass this.
Young amphibians generally undergo metamorphosis from an aquatic larval form with gills to an air-breathing adult form with lungs. Amphibians use their skin as a secondary respiratory interface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin. They are superficially similar to reptiles like lizards, but unlike reptiles and other amniotes, require access to water bodies to breed. With their complex reproductive needs and permeable skins, amphibians are often ecological indicators to habitat conditions; in recent decades there has been a dramatic decline in amphibian populations for many species around the globe.
The earliest amphibians evolved in the Devonian period from tetrapodomorph sarcopterygians (lobe-finned fish with articulated limb-like fins) that evolved primitive lungs, which were helpful in adapting to dry land. They diversified and became ecologically dominant during the Carboniferous and Permian periods, but were later displaced in terrestrial environments by early reptiles and basal synapsids (predecessors of mammals). The origin of modern lissamphibians, which first appeared during the Early Triassic, around 250 million years ago, has long been contentious. The most popular hypothesis is that they likely originated from temnospondyls, the most diverse group of prehistoric amphibians, during the Permian period. Another hypothesis is that they emerged from lepospondyls. A fourth group of lissamphibians, the Albanerpetontidae, became extinct around 2 million years ago. (Full article...)
The Mantellidae are an amphibian family of the order Anura (frogs and toads), and are endemic to the Indian Ocean islands of Madagascar and Mayotte. At first glance, the diminutive, brightly-coloured mantellas appear visually similar to (and indeed fill similar ecological niches as) the Latin American poison dart frogs, such as Dendrobates, Oophaga and Phyllobates, among others. (Full article...)
The salamander is an amphibian of the order Urodela which, as with many real creatures, often has been ascribed fantastic and sometimes occult qualities by pre-modern authors (as in the allegorical descriptions of animals in medieval bestiaries) not possessed by the real organism. The legendary salamander is often depicted as a typical salamander in shape with a lizard-like form, but is usually ascribed an affinity with fire, sometimes specifically elemental fire. (Full article...)
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Toad is a common name for certain frogs, especially of the family Bufonidae, that are characterized by dry, leathery skin, short legs, and large bumps covering the parotoid glands.
In popular culture (folk taxonomy), toads are associated with drier, rougher skin and more terrestrial habitats. However, this distinction does not align precisely with scientific taxonomy. (Full article...)
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The Korean water toad, Korean toad, water toad, or Stejneger's toad (Bufo stejnegeri), is a species of toad found in East Asia. Two distinct populations are known to exist, one in eastern Liaoning province of northeastern China, and one in the central mountains of the Korean Peninsula. Within South Korea, it is found in eastern Gyeonggi (specifically Gapyeong) and also in Gangwon-do (particularly the Odaesan mountain complex). In addition, it is expected that there are or have been additional populations in the region between central Korea and Liaoning.
The classification of the Korean water toad into the genus Bufo was challenged in a 2006 paper. However, no alternative classification was proposed and the species is at present provisionally allocated to Bufo.
The Korean water toad is found inland, at elevations from 200 to 700 meters above sea level. As its name suggests, it favors water, and is typically found in wooded riparian areas. Breeding and egg-laying take place in the waters of streams and rivers. Bufo stejnegeri exhibits specific behaviors during amplexus and egg-laying behavior that make it distinct from other species. Bufo stejnegeri has unique ecology for a toad because they are semi-aquatic and breed in lotic environments. Between November and January, males and females enter streams and immediately begin amplexus. They stay in amplexus for 3–6 months in frozen-over streams until spring spawning (March–April) and lay eggs in fast-flowing streams under rocks. The water toad is typically nocturnal, but is also active during the day during the summer rains. (Full article...)
The Grandisoniidae are a family of common caecilians found in Africa, Seychelles and India. Like other caecilians, they superficially resemble worms or snakes. The family was formerly known as Indotyphlidae. (Full article...)
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