Amphibians are ectothermic, anamniotic, four-limbed vertebrate animals that constitute the class Amphibia. In its broad sense, it is paraphyletic group encompassing all tetrapods excluding the amniotes. All extant (living) amphibians belong to the monophyletic subclass Lissamphibia, with three living orders: Anura (frogs), 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. Their life cycle typically starts out as aquatic larvae with gills known as tadpoles, but some species have developed behavioural adaptations to bypass this.
A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura. The oldest fossil "proto-frog" Triadobatrachus is known from the Early Triassic of Madagascar, but molecular clock dating suggests their split from other amphibians may extend further back to the Permian, 265 million years ago. Frogs are widely distributed, ranging from the tropics to subarctic regions, but the greatest concentration of species diversity is in tropical rainforest. Frogs account for around 88% of extant amphibian species. They are also one of the five most diverse vertebrate orders. Warty frog species tend to be called toads, but the distinction between frogs and toads is informal, not from taxonomy or evolutionary history.
A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found in adult amphibians such as a lateral line, gills and swimming tails. As they undergo metamorphosis, they start to develop functional lungs for breathing air, and the diet of tadpoles changes drastically.
The Pipidae are a family of primitive, tongueless frogs. There are 41 species in the family, found in tropical South America and sub-Saharan Africa.
The glass frogs belong to the amphibian family Centrolenidae. While the general background coloration of most glass frogs is primarily lime green, the abdominal skin of some members of this family is transparent and translucent, giving the glass frog its common name. The internal viscera, including the heart, liver, and gastrointestinal tract, are visible through the skin. When active their blood makes them visible; when sleeping most of the blood is concealed in the liver, hiding them. Glass frogs are arboreal, living mainly in trees, and only come out for mating season. Their transparency conceals them very effectively when sleeping on a green leaf, as they habitually do.
The Mexican burrowing toad is the single living representative of the family Rhinophrynidae. It is a unique species in its taxonomy and morphology, with special adaptations to assist them in digging burrows where they spend most of their time. These adaptations include a small pointed snout and face, keratinized structures and a lack of webbing on front limbs, and specialized tongue morphology to assist in feeding on ants and termites underground. The body is nearly equal in width and length. It is a dark brown to black color with a red-orange stripe on its back along with splotches of color on its body. The generic name Rhinophrynus means 'nose-toad', from rhino- (ῥῑνο-), the combining form of the Ancient Greek rhis and phrunē.
Gastrotheca is a genus of frogs in the family Hemiphractidae. They are found in Central America south of Costa Rica and in South America. Most species occur in the American Cordillera from southern Costa Rica to north-western Argentina. This genus makes up the bulk of marsupial frog diversity; formerly it was placed in the "Leptodactylidae" assemblage.
Adelophryne is a genus of frogs in the family Eleutherodactylidae. They are native to northern South America east of the Andes, known roughly from the area corresponding to the Guiana Shield, as well as to the coastal area of Bahia, Brazil. Whether the genus is truly distinct from Phyzelaphryne remains uncertain. Common name shield frogs has been proposed for this genus, although the stem flea frog is used for some species.
A true toad is any member of the family Bufonidae, in the order Anura. This is the only family of anurans in which all members are known as toads, although some may be called frogs. The bufonids now comprise more than 35 genera, Bufo being the best known.
Ctenophryne is a genus of microhylid frogs. They occur in southern Central America and South America. Their common names are egg frogs and Nelson frogs, the latter applying to species in the formerly recognized Nelsonophryne.
Kaloula is a genus of microhylid frogs found in southern and eastern Asia. They are sometimes known as the Asian narrowmouth toads.
The northern sheep frog is native to Central America, Mexico, and extreme south Texas, United States. It occurs in the lowlands from Sonora, Mexico, to northern Costa Rica on the Pacific coast, and south Texas to Honduras on the Gulf of Mexico and Caribbean coasts. The sheep frog inhabits semiarid thornscrub, savannas, pasturelands, and open woodlands, as well as more humid, moist forest in the canyons, basins, foothills, and lower elevations of mountains slopes. It is a fossorial, burrowing frog that is seldom seen on the surface except at night after heavy rains when they emerge to breed. The sheep frog gets its name from its distinctive call that resembles a sheep's bleat. It is a diet specialist primarily feeding on termites and ants.
Palaeobatrachus is an extinct genus of frogs from Europe that existed from the middle Eocene to the middle Pleistocene, spanning almost 50 million years. They were obligately aquatic, and would have not spent much time on dry land. They are one of two genera and by far the largest genus in the family Palaeobatrachidae, which are considered to be members of Pipimorpha, related to the South American-African family Pipidae, which includes the African clawed frog and Surinam toad.
Pipa aspera, the Albina Surinam toad, is a species of frog in the family Pipidae found in French Guiana, Suriname, and possibly Brazil. Its natural habitats are subtropical or tropical moist lowland forests, rivers, freshwater marshes, and intermittent freshwater marshes. The color of this species is a reddish-brown to a brownish-black, noticed on the dorsal part of its body. The weights of females range between 5 and 12 grams, and males between 4 and 7 grams, noting that females are usually significantly larger.
Pipa parva, is a species of frog in the family Pipidae. It is found in northwestern Venezuela and northeastern Colombia, mainly in the Maracaibo Basin. There is an introduced population in the Lake Valencia Basin in northern Venezuela.
Raorchestes ponmudi is a species of frog in the family Rhacophoridae. It is endemic to the Western Ghats, India.
Brevicipitidae or rain frogs is a small family of frogs found in eastern and southern Africa. As of 2020 contains 37 species in 5 genera. Formerly included as subfamily in Microhylidae, phylogenetic research has indicated the brevicipitine frogs should be considered as a family with Hemisotidae as the most closely related sister taxon.
The Hemiphractidae are a family of frogs from South and Central America. Previously, this group had been classified as a subfamily (Hemiphractinae) under family Hylidae. More recent research classifies these genera into their own family, or sometimes into three separate families: Amphignathodontidae, Cryptobatrachidae, and Hemiphractidae. An active question still exists as to which of these groupings is more accurate.
The common Surinam toad or star-fingered toad is a purely aquatic species of frog in the family Pipidae with a widespread distribution in South America. The species is known for incubating its eggs in honeycombed chambers in the skin of the mother's back, releasing fully formed froglets after a period of 4–5 months. It is an ambush predator that lies in wait in the water for prey to come into range, which it then captures using suction feeding.
Ceuthomantis is a small genus of craugastorid frogs, also treated as comprising their own monogeneric family Ceuthomantidae. They are found in the southern and eastern parts of the Guiana Highlands in Venezuela, Guyana, and Brazil. The generic name is derived from the Greek noun mantis, which means treefrog, and adjective keuthos, which means hidden, in allusion to the hidden existence of this genus in the tepuis of the Guiana Shield.
