The Lissamphibia is a group of tetrapods that includes all modern amphibians. Lissamphibians consist of three living groups: the Salientia, the Caudata, and the Gymnophiona.
The Caudata are a group of amphibians containing the extant salamanders and all extinct species of amphibians more closely related to salamanders than to frogs. They are typically characterized by a superficially lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults.
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 Batrachia are a clade of amphibians that includes frogs and salamanders, but not caecilians nor the extinct allocaudates. The name Batrachia was first used by French zoologist Pierre André Latreille in 1800 to refer to frogs, but has more recently been defined in a phylogenetic sense as a node-based taxon that includes the last common ancestor of frogs and salamanders and all of its descendants. The idea that frogs and salamanders are more closely related to each other than either is to caecilians is strongly supported by morphological and molecular evidence; they are, for instance, the only vertebrates able to raise and lower their eyes. However, an alternative hypothesis exists in which salamanders and caecilians are each other's closest relatives as part of a clade called the Procera, with frogs positioned as the sister taxon of this group.
Dissorophoidea is a clade of medium-sized, temnospondyl amphibians that appeared during the Moscovian in Euramerica, and continued through to the Late Permian and the Early Triassic of Gondwana. They are distinguished by various details of the skull, and many species seem to have been well adapted for life on land.
The Cryptobranchoidea are a suborder of salamanders found in Asia, European Russia, and the United States. They are known as primitive salamanders, in contrast to Salamandroidea, the advanced salamanders. It has two living subdivisions, Cryptobranchidae, which includes Asian giant salamanders and hellbenders, and Hynobiidae, commonly known as Asian salamanders.
Albanerpeton is an extinct genus of salamander-like albanerpetontid amphibian found in North America, Europe and Asia first appearing in Cretaceous-aged strata. There are eight described members of the genus, and one undiagnosed species from the Paskapoo Formation, making it by far the most speciose genus in the family. Members of the genus had a robust head and neck which likely allowed them to actively burrow, characteristic of fossorial species, and they lived in a wide range of environments. This genus of amphibian was the last of its order, surviving until into the Early Pleistocene (Gelasian) of northern Italy, and possibly northern Spain, until around 2 million years ago. It likely became extinct when the region developed its present Mediterranean-type climate, having preferred one that was cold and humid. The monophyly of Albanerpeton has recently been questioned, with some authors regarding the genus as paraphyletic.
Apodops is an extinct genus of early caecilians from the Early Eocene Itaboraí Formation of Brazil. The type species of the genus is A. pricei, described based on an isolated and broken trunk vertebra.
Anoualerpeton is an extinct genus of lissamphibian in the family Albanerpetontidae. It is the oldest and most primitive albanerpetontid known. Fossils have been found of two different species, Anoualerpeton priscus from the Middle Jurassic (Bathonian) aged Forest Marble and Kilmaluag formations of England and Scotland, and Anoualerpeton unicus from Late Jurassic-Early Cretaceous (Tithonian-Berriasian) Ksar Metlili Formation of Morocco. A. unicus is the only named albanerpetontid from Gondwana.
Celtedens is an extinct genus of albanerpetontid amphibian from the Early Cretaceous of England, Spain, Sweden and Italy, and the Late Jurassic of Portugal.
Horezmia is an extinct Mesozoic genus of prehistoric salamanders. The fossils have been found in Russia. It is comparable to modern advanced salamanders, though its phylogenetic placement within Salamandroidea is uncertain.
The Balabansai Formation is a geological formation in Kazakhstan, Kyrgyzstan and Uzbekistan whose strata date back to the Bathonian and Callovian stages of the Middle Jurassic. Dinosaur remains are among the fossils that have been recovered from the formation. The lithology primarily consists of variegated sandstones, siltstones, claystones, and rare gravels and marls. Many taxa have been found in the formation, including amphibians and mammals
Wesserpeton is an extinct genus of albanerpetontid amphibian known from the Isle of Wight, southern England.
The Karauridae are a family of stem-group salamanders (Caudata) that are known from the Middle Jurassic to Early Cretaceous in Central Asia, Northern Asia and Western Europe. The family includes four members: Karaurus from the Middle-Late Jurassic Karabastau Formation of Kazakhstan, Kokartus from the Middle Jurassic Balabansai Formation of Kyrgyzstan, Marmorerpeton from the Middle Jurassic Forest Marble Formation of England and Kilmaluag Formation of Scotland, and Kuzbassia from the Early Cretaceous (Aptian) Ilek Formation. The members are some of the oldest known salamanders. The family is united by several morphological characters, including sculptured skull roof bones. Like some modern salamanders, karaurids were neotenic. Members of the family likely fed via suction feeding on small fish and invertebrates. The Early Cretaceous Siberian Kulgeriherpeton has been suggested to be a karaurid by some authors.
Shirerpeton is an extinct genus of albanerpetontid amphibian from the Early Cretaceous Kuwajima Formation, which is located in Japan. The type species is Shirerpeton isajii, which was described by Masumoto & Evans in 2018. Shirerpeton represents the first record of Albanerpetontidae in East Asia and the holotype is SBEI 2459, a small block bearing most of a disarticulated but associated skull with some postcranial elements present as well.
Chinlestegophis is a diminutive Late Triassic stereospondyl that has been interpreted as a putative stem caecilian, a living group of legless burrowing amphibians. If Chinlestegophis is indeed both an advanced stereospondyl and a relative of caecilians, this means that stereospondyls survived to the present day; historically the group was thought to have gone extinct by the early Cretaceous. Chinlestegophis jenkinsi, the type and only species, is known from two partial skulls discovered in the Chinle Formation in Colorado.
The Ksar Metlili Formation is a geological formation in eastern High Atlas of Morocco, it is late Tithonian to Berriasian in age. It is approximately 80 metres (260 ft) thick and primarily consists of mudstone and sandstone, with thin calcareous beds. One of these calcareous beds near the middle of the sequence is an important microvertebrate locality. Subsequent to the original site, several other localities have been sampled. The depositional environment is thought to be near shore deltaic.
Yaksha perettii is an extinct species of albanerpetontid amphibian, and the only species in the genus Yaksha. It is known from three specimens found in Cenomanian aged Burmese amber from Myanmar. The remains of Yaksha perettii are the best preserved of all albanerpetontids, which usually consist of isolated fragments or crushed flat, and have provided significant insights in the morphology and lifestyle of the group.
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.
Funcusvermis is an extinct genus of stem-caecilian from the Late Triassic of Arizona. It is based on a large sample of jaws and other skull and postcranial fragments, discovered in an approximately 220 million years old layer of rock in the Blue Mesa Member of the Chinle Formation at Petrified Forest National Park. There is a single species, called Funcusvermis gilmorei.
