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.
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.
The Rhinophrynidae are a family of frogs containing one extant genus, the monotypic Rhinophrynus, and a number of fossil genera. The family is sometimes known as the Mexican burrowing toads or simply burrowing toads.
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.
Notobatrachus is an extinct genus of frog from the Lower Jurassic (Toarcian) Cañadon Asfalto Formation, Cañadón Asfalto Basin and Middle Jurassic La Matilde Formation, Deseado Massif of Patagonia, Argentina. N. degiustoi is the most completely known Jurassic frog and has been recorded in many outcrops of the La Matilde Formation of the Deseado Massif in southern Patagonia.
The Albanerpetontidae are an extinct family of small amphibians, native to the Northern Hemisphere during the Mesozoic and Cenozoic. The only members of the order Allocaudata, they are thought to be allied with living amphibians belonging to Lissamphibia. Despite a superficially salamander-like bodyform, their anatomy is strongly divergent from modern amphibians in numerous aspects. The fossil record of albanerpetontids spans over 160 million years from the Middle Jurassic to the beginning of the Pleistocene, about 2.13–2 million years ago.
The Allen Formation is a geological formation in Argentina whose strata date back to the Late Cretaceous (middle Campanian to early Maastrichtian. Dinosaur remains are among the fossils that have been recovered from the formation. Indeterminate chelid remains and other vertebrates have also been discovered in this formation.
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.
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.
Rhadinosteus parvus is an extinct species of prehistoric frogs that lived during the Late Jurassic. Fossils of the species were found at the Rainbow Park site in Utah's Dinosaur National Monument, from several slabs of rock which contain multiple partial specimens, from sediments belonging to the Morrison Formation. R. parvus was likely a member of Pipoidea and may have been a member of the family Rhinophrynidae.
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.
Shelania is an extinct genus of prehistoric frogs that lived in South America during the Eocene. Its type species is Shelania pascuali. Fossils of Shelania have been found in the Mustersan Vaca Mahuida and Laguna del Hunco Formations of Argentina. Shelania is the type taxon of the Shelaniinae, which was erected for an unranked clade that also includes the early anurans Saltenia, Kuruleufenia, and Patagopipa. A more recent phylogenetic analysis further suggested that Shelania is more closely related to Pipidae than to Palaeobatrachus, and that the second species previously attributed to Shelania is not sufficiently closely related to the type-species to be retained in Shelania.
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. A recent phylogenetic analysis confirmed this conclusion, and further suggested that Thoraciliacus rostriceps is more closely related to Pipidae and Shelaniinae than to Palaeobatrachus. 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.
Crossognathiformes is an extinct order of ray-finned fish that lived from the Late Jurassic to the Eocene. Its phylogenetic placement is disputed; some authors have recovered it as part of the teleost stem group, while others place it in a basal position within crown group Teleostei. Other placements have found it to be polyphyletic, with Varasichthyidae being stem-group teleosts whereas the other, "true" crossognathiforms are crown-group teleosts within Teleocephala.
The Calyptocephalellidae are a family of toads found in Chile containing two living genera, Calyptocephalella and Telmatobufo.
Palaeobatrachidae is an extinct family of frogs known from the Late Cretaceous to the Pleistocene primarily of Europe. They were highly adapted to aquatic life, like other members of the Pipimorpha. The oldest undoubted records of the family are from the lower Campanian of France. By far the most abundant genus is Palaeobatrachus, known from the Eocene to Pleistocene of Europe, with most other named genera in the family synonymised with it, the only exception being Albionbatrachus, which is distinguished from Palaeobatrachus by characters of its frontoparietals. The youngest fossils of Palaeobatrachus date to around 500,000 years ago, during the Middle Pleistocene after which they likely became extinct due to increasing aridity and freezing temperatures during the ice ages. Fossils of indeterminate palaeobatrachids are also known from the Pliocene and Early Pleistocene of Western Siberia.
The Cañadón Asfalto Basin is an irregularly shaped sedimentary basin located in north-central Patagonia, Argentina. The basin stretches from and partly covers the North Patagonian Massif in the north, a high forming the boundary of the basin with the Neuquén Basin in the northwest, to the Cotricó High in the south, separating the basin from the Golfo San Jorge Basin. It is located in the southern part of Río Negro Province and northern part of Chubut Province. The eastern boundary of the basin is the North Patagonian Massif separating it from the offshore Valdés Basin and it is bound in the west by the Patagonian Andes, separating it from the small Ñirihuau Basin.
The Huitrera Formation is a geological formation in the Neuquén Basin in northern Patagonian Argentina whose strata date back to the Early Eocene of the Paleogene, or Casamayoran in the South American land mammal age classification.
This list of fossil amphibians described in 2020 is a list of new taxa of fossil amphibians that were described during the year 2020, as well as other significant discoveries and events related to amphibian paleontology that occurred in 2020.
