Portal:Amphibians

The Amphibian Portal

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 lepospondys. A fourth group of lissamphibians, the Albanerpetontidae, became extinct around 2 million years ago. (Full article...)

Selected frog article

Nyctibatrachidae is a small family of frogs found in the Western Ghats of India and in Sri Lanka. Their common name is robust frogs. Recognition of Nyctibatrachidae as a family is fairly recent. These frogs were previously placed in the broadly defined family Ranidae, which was more recently divided into three subfamilies: Lankanectinae, Nyctibatrachinae, and Astrobatrachinae. (Full article...)
List of selected frog articles

Selected salamander article

A salamnder
Bestiary, 14th cent.
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...)
A Hurdia victoria
A Hurdia victoria

Selected amphibian type

European fire-bellied toad (Bombina bombina), a member of the family Bombinatoridae

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.

A distinction between frogs and toads is not made in scientific taxonomy, but is common in popular culture (folk taxonomy), in which toads are associated with drier, rougher skin and more terrestrial habitats. (Full article...)
List of selected amphibian type articles

Selected images

Selected toad article

Geographic range in South America
The Carchi Andes toad (Rhaebo colomai) is a species of toad endemic to the western slopes of the Andes in northern Ecuador and southern Colombia. It is listed as an endangered species due to a restricted range and habitat loss. (Full article...)
List of selected toad articles

Selected caecilian article

Rhinatrematidae is a family of caecilians, also known as the Neotropical tailed caecilians, American tailed caecilians. or beaked caecilians. They are found in the equatorial countries of South America.

They are usually regarded as the most basal of the caecilian families, with numerous characteristics lacking in the other groups. For example, they still possess tails, and their mouths are not recessed on the underside of their heads. They lay their eggs in cavities in the soil. The larvae have external gills, and live in seepage areas until they metamorphose. The adults live in moist soil and leaf litter. (Full article...)

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