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.
The African clawed frog, also known as simply Xenopus, African clawed toad, African claw-toed frog or the Platanna) is a species of African aquatic frog of the family Pipidae. Its name is derived from the short black claws on its feet. The word Xenopus means 'strange foot' and laevis means 'smooth'.
True frogs is the common name for the frog family Ranidae. They have the widest distribution of any frog family. They are abundant throughout most of the world, occurring on all continents except Antarctica. The true frogs are present in North America, northern South America, Europe, Africa, and Asia. The Asian range extends across the East Indies to New Guinea and a single species, the Australian wood frog, has spread into the far north of Australia.
Caecilians are a group of limbless, vermiform (worm-shaped) or serpentine (snake-shaped) amphibians with small or sometimes nonexistent eyes. They mostly live hidden in soil or in streambeds, and this cryptic lifestyle renders caecilians among the least familiar amphibians. Modern caecilians live in the tropics of South and Central America, Africa, and southern Asia. Caecilians feed on small subterranean creatures such as earthworms. The body is cylindrical and often darkly coloured, and the skull is bullet-shaped and strongly built. Caecilian heads have several unique adaptations, including fused cranial and jaw bones, a two-part system of jaw muscles, and a chemosensory tentacle in front of the eye. The skin is slimy and bears ringlike markings or grooves and may contain scales.
The Mesobatrachia is a paraphyletic group of relatively primitive frogs. At the end of 2016, it contained 3 superfamilies, 6 families, 16 genera, and 244 species. Recognized as a group in 1993, the name is contrasted with the primitive Archaeobatrachia and the more diverse and advanced Neobatrachia.
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.
Lepidotes is an extinct genus of Mesozoic ray-finned fish. It has long been considered a wastebasket taxon, characterised by "general features, such as thick rhomboid scales and, for most of the species, by semi-tritorial or strongly tritorial dentition". with dozens of species assigned to it. Fossils attributed to Lepidotes have been found in Jurassic and Cretaceous rocks worldwide. It has been argued that Lepidotes should be restricted to species closely related to the type species L. gigas, which are only known from the Early Jurassic of Western and Central Europe, with most other species being not closely related, with other species transferred to new genera such as Scheenstia.Lepidotes belongs to Ginglymodi, a clade of fish whose only living representatives are the gars (Lepisosteidae). The type species L. gigas and close relatives are thought to be members of the family Lepidotidae, part of the order Lepisosteiformes within Ginglymodi, with other species occupying various other positions within Ginglymodi.
Beelzebufo is a particularly large species of prehistoric frog described in 2008. Common names assigned by the popular media include devil frog, devil toad, and the frog from hell.
Birgeria is a genus of carnivorous marine ray-finned fish from the Triassic period. Birgeria had a global distribution, with fossil known from Madagascar, Spitsbergen, Germany, Switzerland, Italy, Slovenia, China, Russia, Canada and Nevada, United States. The oldest fossils are from Griesbachian aged beds of the Wordie Creek Formation of East Greenland. Birgeria existed throughout the entire Triassic period, from the very beginning just after the Permian-Triassic mass extinction, up to the very end with its extinction during the Triassic-Jurassic mass extinction.
Avitabatrachus uliana is the only species discovered so far in the extinct genus Avitabatrachus, a genus of prehistoric frogs that lived in the Middle Cretaceous. Fossils of A. uliana were found in the Candeleros Formation of northwestern Patagonia in Argentina. This prehistoric amphibian was properly described in 2000 and was then concluded to be most closely related to Pipidae frogs. Hence, it was included in Pipimorpha. A subsequent phylogenetic analysis confirmed this conclusion, and further suggested that Avitabatrachus uliana is more closely related to Pipidae and Shelaniinae than to Palaeobatrachus.
Baurubatrachus is an extinct genus of prehistoric frogs found in the Maastrichtian Marília Formation of Brazil, formerly considered to be related to the extant family Ceratophryidae. However, a detailed assessment of the anatomy and relationships of the single known fossil of Baurubatrachus demonstrated that it is not part of Ceratophryidae and might be part of a much ancient group of Neobatrachia.
Nevobatrachus gracilis is the only species in the extinct genus Nevobatrachus, a genus of prehistoric frogs. The original generic name of this frog was Cordicephalus Nevo (1968); however, this generic name turned out to be preoccupied by a cestode genus Cordicephalus Wardle, McLeod & Stewart (1947), which remains nomenclaturally available in spite of being considered a junior synonym of the diphyllobothriid genus Pyramicocephalus. Mahony (2019) coined a replacement name Nevobatrachus. Fossils of N. gracilis were found in a lacustrine deposit in Makhtesh Ramon called "Amphibian Hill" and it is believed they lived during the Lower Cretaceous.
Eodiscoglossus is an extinct genus of prehistoric frogs. It is known from the type species E. santonjae from the Early Cretaceous (Barremian) El Castellar Formation of Spain, as well as a referred species E. oxoniensis known from the Forest Marble Formation of the UK and an indeterminate species from the Dzunbain Formation of Mongolia. It was a small primitive frog, with a length of only 27 mm (1.1 in) from the premaxilla to the ischium. Formerly considered to be closely related to discoglossids, E. santonjae is now regarded as close to the root of the crown group of modern frogs in a position more derived than New Zealand frogs and tailed frogs, but more basal than costatans like alytids and other more advanced frogs like neobatrachians. The morphology of E. santonjae suggests a generalist and unspecialised movement habit. The referral of E. oxoniensis to Eodiscoglossus has been questioned, as it is much earlier than the type species and it is based on homoplasic and plesiomorphic characteristics inherited from a common ancestor, so there is no clear evidence of a close relation.
Vulcanobatrachus is an extinct genus of fossil frog. The genus contains the single species Vulcanobatrachus mandelai found at Marydale, South Africa, described in 2005 and named after Nelson Mandela. The genus owes its name to the fact that fossils were recovered from an extinct volcanic crater lake of Late Cretaceous age. The fossil frogs are assumed to have died following a limnic eruption (a degassing event possibly of CO2) by the volcano.
Pachycentrata is an extinct genus of prehistoric amphibian.
Llankibatrachus is an extinct genus of prehistoric frogs in the family Pipidae. They are known from the Ypresian (Casamayoran) Huitrera Formation of Argentina.
Singidella is an extinct genus of prehistoric frog from the Eocene of Tanzania. There is currently only one described species, S. latecostata. Its generic name is derived from Singida, the city near which the only known specimens were found, and the specific name translates as "wide ribs" from Latin. It is a member of the family Pipidae and is closely related to the extant African dwarf frogs (Hymenochirus) and Merlin's dwarf gray frog (Pseudohymenochirus) and the Cretaceous frog Pachycentrata of Niger. Adult individuals were estimated at 41-45 mm in length from snout to vent.
Prohalecites is an extinct genus of ray-finned fish from the Ladinian and possibly Carnian (Triassic) of Italy. It is the oldest known teleosteomorph, a group that includes extant teleosts and their close fossil relatives.
Thoraciliacus rostriceps is an extinct species of frog from the Cretaceous period and the only species of the genus Thoraciliacus, which is classified in the unranked clade Pipimorpha. Fossils of T. rostriceps were found in Makhtesh Ramon, Negev Desert, Israel and it is believed they lived during the Barremian. Other fossils have been found near Marydale, South Africa in an Upper Cretaceous lake.
Pipoidea are a clade of frogs, that contains the most recent common ancestor of living Pipidae and Rhinophrynidae as well as all its descendants. It is broadly equivalent to Xenoanura.
