Image of Eryops, an extinct temnospondyl (left) and Xenopus, the extant African Clawed Frog.

Image of Eryops from: http://www.bertsgeschiedenissite.nl/geschiedenis%20aarde/amfibieen.htm

Image of Xenopus from the Systematic Biology Biodiversity Archive.

CLASS BATRACHOMORPHA (AMPHIBIA)

Benton (2004) uses the term Batrachomorpha to define a monophyletic group that includes the extinct Temnospondyls and the living amphibians (Lissamphibia: caecilians, frogs, and salamanders).  These groups are united by several synapomorphies including four digits on the forefeet, a flattened skull with fused skull elements, stalked or pedicillate teeth, 26 or fewer presacral vertebrae, large orbits, paired occipital condyles, and the maxilla articulates with the quadratojugal.  They are aquatic or tied to an aquatic environment through reproduction.  Most lay eggs in water and require water for an aquatic larval stage.

SUBCLASS TEMNOSPONDYLI+

Skull frog-like, triangular to parabolic with polygonal pattern.  Many had a lateral line.  Some known to have gilled larvae (tadpoles).  A large opening in the palate and several large fangs attached to the palate, as well.  Though most were adapted to an aquatic existence, the later taxa had several lines that were primarily terrestrial.  They are characterized by having complex, primitive vertebrae made of separate unfused components that include the pleurocentra, intercentra, neural arches, and zygopophyses.  Some evolved a weaker (more aquatic) structure in which the pleurocentra were lost or highly reduced.

Carboniferous to Triassic (lower Cretaceous).

ORDER UNNAMED

FAMILY TRIMERORACHIDAE

THE DVINOSAURIA

Broad skulls and lateral line. 

Permian to Triassic

FAMILY ARCHEGOSAURIDAE

FAMILY RHINESUCHIDAE

Tupilakosaurus

THE CAPITOSAURIA

Broad flat skulls of animals that were semi-aquatic to fully aquatic and common denizens of freshwater environments.  Some very large (3-4m).  

Triassic

FAMILY MASTODONSAURIDAE

FAMILY CAPITOSAURIDAE

Benthosuchus

THE TREMATOSAURIA

Mostly aquatic and mostly restricted to the Triassic

FAMILY TREMATOSAURIDAE

FAMILY METAPOSAURIDAE

FAMILY PLAGIOSAURIDAE

Short broad skulls and reduced limbs, clearly aquatic.

Triassic

Plagioscutum

FAMILY RHYTIDOSTEIDAE

FAMILY BRACHYOPIDAE

To the upper Jurassic

FAMILY CHIGUTISAURIDAE

To the lower Cretaceous

Koolasuchus

THE TEMNOSPONDYLS

FAMILY DENDRERPETONTIDAE

Large skulls with rounded anterior.  Well developed middle ear apparatus suggests a terrestrial existence.

Carboniferous

Balanerpeton, Denderpeton

FAMILY ERYOPIDAE

Massive skeleton, terrestrial form.

Lower Permian

Eryops

FAMILY DISSOROPHIDAE

Animals likely terrestrial; short skulls with very large eyes and large ear drums.

Lower Permian

Doleserpeton

FAMILY BRANCHIOSAURIDAE

These seem to have become paedomorphic, sexually mature as larvae.

Upper Carboniferous (Pennsylvanian) to Lower Permian

Branchiosaurus

FAMILY AMPHIBAMIDAE

SUBCLASS LISSAMPHIBIA

These animals have teeth that are bicuspid and pedicillate.  They are sisters to the temnospondils or part of the same clade. Pough et al. (1998) summarize evidence that suggests the Lissamphibia arose as paedomorphic temnospondyls.  Evidence cited refers to similarities between larval temnospondyls and lissamphibia relative to reductions in skull elements, similar kinds of teeth, and large eyes.

ORDER UNNAMED?+

FAMILY ALBANERPETONTIDAE

The body was long and salamander-like.  The tail was short and mostly unusually thin.  Also, their neck vertebrae were reduced to an atlas and axis, which were fused to the first thoracic vertebrae.  These likely were features that were adaptations to burrowing.

Middle Jurassic to Miocene

Albanerpeton, Celtedens

ORDER GYMNOPHIONA

The caecilians look like earthworms (also called apoda).  They are legless and burrow or swim (tropical taxa).  Their vertebral column may have more than 200 vertebrae.

Lower Jurassic to present

Eocaecilia+

FAMILY RHINATREMATIDAE

American Tailed Caecilians.  Wet terrestrial environments (seeps, wet leaf litter, underground) of northern South America .  These animals have a tail, a terminal mouth, a skull with some bony elements, and a sensory tentacle in contact with the eye. 

Epicrionops, Rhinatrema.

FAMILY ICHTHYOPHIIDAE

Asiatic Tailed Caecilians.  Semi-aquatic animals of tropical Asia , including southeastern Asia . The mouth is terminal, the skull has bony elements, they possess a tail.  They lay eggs in water and guard them until hatched as aquatic larvae.

Caudacaecilia, Ichthyophis.

FAMILY URAEOTYPHLIDAE

Indian Caecilians.  Terrestrial animals of India .  They have a short tail and a skull with some bony elements.  Oviparous.

Uraeotyphlus.

FAMILY SCOLEOMORPHIDAE

African Caecilians.  Fossorial animals of Camaroon and Tanzania .  The most distinctive feature of these animals is the association of the eyes with the sensory tentacles such that the eyes stay at the tips of the tentacles when they are extended.  The animals have no tail and are viviparous.

Crotaphatrema, Scoleocomorphus.

FAMILY CAECILIIDAE

Caecilians.  Mainly terrestrial animals of tropical Americas , tropical Africa , tropical western India , the Seychelle Islands .  They have no tail and vary between ovipary (lay eggs on land) and vivipary. 

Boulengerula, Brasilotyphlus, Caecilia, Dermophis, Gegeneophis, Geotrypetes, Gymnopis, Herpele, Hypogeophis, Idiocranium, Indotyphlus, Luetkenotyphlus, Microcaecilia, Mimosiphonops, Oscaecilia, Parvicaecilia, Prasilinia, Schistometopum, Siphonops, Sylvacaecilia.

FAMILY TYPHIONECTIDAE

Aquatic Caecilians.  Freshwater (secondarily aquatic) in northern South America .  All are viviparous; they have tracheal lungs (one lacks lungs), narial plugs.  They lack annular scales, secondary annuli, and tails.  However, they do have a fin that occurs along much of the length of the posterior end of the body.  The sensory tentacle is not protrusible.  The animals are mostly aquatic and burrow in the bottom or at water level.

Atretochoana, Chthonerpeton, Nectocaecilia, Potomotyphlus, Typhlonectes.

ORDER URODELA (CAUDATA)

The salamanders and newts (also called caudata) show few specialized features relative to the non-amniote tetrapods.  Living salamanders have four legs, a short body, and a long tail, though some taxa have lost their limbs entirely.  They do not have middle ear cavities or external ears (they hear by means of a structure called the opercular apparatus).  Salamanders range in size from 3cm to 2m. 

Middle Jurassic to the present

Karaurus+ (Jurassic of Russia )

FAMILY SIRENIDAE

Sirens.  Freshwater and fully aquatic; in swamps, lakes, and marshes of the southeastern US to northern Mexico .  Eel-like salamanders that have no pelvic limbs or girdles; they have no eyelids.  They have reduced or lost the maxilla, and have external gills and nonpedicillate teeth.  Maximum length nearly 1m.

Siren, Pseudobranchus.

FAMILY CRYPTOBRANCHIDAE

Hellbenders.  Freshwater; cold mountain or rocky streams; disjunct distribution Japan and central China , and eastern North America .  Adults undergo incomplete metamorphosis; and have no eyelids, and possess a gill slit.  The head and body are flattened.  Cutaneous respiration.  Maximum length up to 1.8m.

Andrias, Cryptobranchus.

FAMILY HYNOBIIDAE

Asiatic Salamanders.  Freshwater and terrestrial; mountain streams and ponds from the Ural Mountains to the Pacific south to China , Japan , Afganistan, and Iran .  These animals undergo complete metamorphosis (have eyelids and have no gill slits as adults). 

Batrachuperus, Hynobius, Onychodactylus, Ranodon.

FAMILY AMPHIUMIDAE

Amphiumas or Congo Eels.  Aquatic salamanders of the southeastern US.  They are paedomorphic with highly reduced limbs.  They have no eyelids or tongues.  Maximum length over a meter.

Cretaceous to the present

Amphiuma, Proamphiuma+.

FAMILY PLETHODONTIDAE

Lungless Salamanders.  They occur from the northeastern and northwaestern US to tropical America ; one species in southern Europe .  They have a chemosensory nasolabial groove, and all lack lungs and exchange gasses through their moist skin.  All have 4 digits on their forelimbs.

Miocene to present

Aneides, Batrachoseps, Bolitoglossa, Chiropterotriton, Dendrotriton, Desmognathus, Ensatina, Gyrinophylus, Haideotriton, Hemidactylium, Hydromantes, Ixalotriton, Leurognathus, Lineatriton, Nototriton, Nyctanolis, Oedipina, Parvimolge, Phaeognathus, Plethodon, Pseudoeurycea, Pseudotriton, Stereochilus, Thorius, Typhlotriton.

FAMILY RHYACOTRITONIDAE

Torrent Salamanders.  They are found in fast-moving streams of the northwestern US, particularly in the Cascades.  They unusual squared glands near the vent.  They have no operculum, and very reduced lungs.  They have complete metamorphosis (but the larval development is very slow, up to 3 years).

Rhyacotriton.

FAMILY PROTEIDAE

Mudpuppies and Waterdogs.  Two species of aquatic salamanders: one in northeastern US and the other in limestone caves of southeastern Europe .  There is no metamorphosis; the adults are paedomorphic with distinctive external gills and a caudal fin.  Adults have 2 gill slits.

Miocene to the present

Necturus, Proteus, Mioproteus+, Orthophyla+.

FAMILY SALIMANDRIDAE

Newts and Salamanders.  These animals occur in four disjunct locations: Europe , northern Africa , Asia , and the US .  Salamanders have slimy skin, but newts have smooth skin that is not slimy.  All produce toxic skin secretions.  All seem to have a fronto-squamosal arch, and most have well-developed lungs. 

Eocene to present

Chioglossa, Cynops, Euproctus, Mertensiella, Neurergus, Notophthalmus, Pachytriton, Paramesotriton, Pleurodeles, Salamandra, Taricha, Triturus, Tylototriton.

FAMILY AMBYSTOMATIDAE

Mole Salamanders.  Burrowers, they occur from southeastern Alaska to the Mexican plateau.  They have stout bodies, thick tails, and smooth skin.  Most go through complete metamorphosis, but some “elect” to remain in the larval condition. 

Upper Pliocene to the present.

Ambystoma, Amphitriton+.

FAMILY DICAMPTODONTIDAE

Pacific Giant Salamanders.  They occur in conifer forests of the Pacific Northwest (northern California to southern Canada ).  They have well-developed lungs, blade-like teeth, ossified carpals and tarsals, and complete metamorphosis (come with “elective” paedomorphosis).

Paleocene to the present.

Dicamptodon.

ORDER ANURA

The frogs and toads (also called salientia) are highly modified to a jumping locomotion.  They have lost their tails and have reduced the ribs and vertebrae. 

Lower Jurassic to present

FAMILY ASCAPHIDAE

Tailess frogs.  Frogs of cold mountain streams of Washington , Oregon , Idaho , and Montana .  These are likely the most primitive of the extant frogs and sisters to all of the rest.  They have an extension of the cloaca (a structure that functions in internal fertilization; no other frogs have internal fertilization) that looks like a tail.  They have 9 presacral vertebrae (all other frogs have fewer).

Jurassic to the present (Paragonia, North America , New Zealand ).

Ascaphus.

FAMILY LEIOPELMATIDAE

New Zealand Frogs.  Frogs of North Island , New Zealand .  They are similar to the Ascaphids and have a similar group of primitive characters: no tympana, 9 presacral vertebrae which also have amphicoelous centra.  They have bony ribs.  They also develop directly (no larval stage) from terrestrial eggs that are guarded by the adults.  Young may be cared for by the adults.

Jurassic to the present.

Leiopelma.

FAMILY BOMBINATORIDAE

FAMILY DISCOGLOSSIDAE

Fire Belly Frogs.  These are small toads of Europe , Middle-East, and northern Africa .  They have a primitive pectoral girdle, and opisthocoelus vertebrae.  After the eggs are fertilized (in water), the male collects them and carries them on his back and hind legs until they are ready to hatch.  Then, he returns them to the water, where the larvae develop.

Upper Jurassic to the present

Alytes, Barbourula, Bombina, Discoglossus.

FAMILY PELOBATIDAE

Spadefoot Toads.  These fossorial toads occur in dry areas of North America , Europe , western Asia , and northern Africa .  They are named for a specialized structure made of a bony extension of the metatarsal on the outside of the hindfoot.  The “spade”, as its name implies, functions as a digging tool which allos the toad to burrow hind-end first into a soft substrate, usually sand.  They have large eyes with vertical pupils.  Inaddition, they have a round body with short limbs.  Aside from the spade, synapomorphies include the fusion of the sacrum and coccyx.  Adults lack ribs, and the astragulus and calcaneus are fused at the ends.  The tadpoles undergo indirect development.  They spend most of their lives underground and emerge only after soaking rains.  They lay eggs in temporary pools; so, the tadpoles go through a rapid development before the pool dries.

Oligocene to the present.

Ophryophryne, Pelobates, Scaphiopus, Scutiger, Spea.

FAMILY PELODYTIDAE

Parsley Frogs. Fossorial frogs from western Europe and the Caucasus mountains .  The astragalus and calcaneum are fused along the entire length.  Their presacral vertebrae (I and II) are fused and they do not have ribs.  They produce aquatic larvae (tadpoles) that develop indirectly. 

Eocene to the present.

Pelodytes, Miopelodytes+, Propelodytes+.

FAMILY RHINOPHRYNIDAE

Burrowing Toads.  Fossorial toad that occurs from southern Texas to Costa Rica .  They have an arciferal pectoral girdle, a spade on the heel of the hind feet.  The head is acutely pointed, and they lack a tympanum and have small eyes.  The tongue projects straight out of the mouth (it does not flip out).  They emerge from burrows after heavy rains and lay eggs in ephemeral pools.  The larvae are filter-feeders.

Paleocene to the present.

Rhinophrynus

FAMILY PIPIDAE

Tongueless Frogs.  Aquatic frogs of tropical South America and sub-Saharan Africa .  Their feet are webbed, and they have a lateral line system.  Their ears and vocal apparatus are adapted to producing and receiving sound while underwater.  They have no tongue.  Some have claw-like structures. 

Lower Cretaceous to the present.

Hymenochirus, Pipa, Pseudohymenochirus, Xenopus/

FAMILY ALLOPHRYNIDAE

FAMILY BRACHYCEPHALIDAE

Gold Frogs and Shield Toads.  Frogs of the humid forests of southeastern Brazil along the Atlantic coast.  They are tiny (some <1cm) with only 3 toes on each hindfoot and two on each forefoot.  They have no sternum.  They are diurnal and live in the leaf litter.  They have direct development of eggs that have been laid on land.

Brachycephalus, Psyllophryne.

FAMILY BUFONIDAE

True Toads. Toads are found throughout the temperate and tropical areas of the world except Madagascar , islands east of the Wallace Line, including Australia , and Oceania .  Males develop an ovary at the front end of the testes.  They have no teeth, large parotid glands.  Skulls are ossified.  Most are terrestrial, a few are aquatic and a few are arboreal.  They range from complete metamorphosis to viviparity. 

Upper Paleocene to present

Ansonia, Atelopus, Bufo, Capensibufo, Crepidophryne, Dendrophryniscus, Didynamipus, Frostius, Laurentophryne, Leptophryne, Melanophryniscus, Mertensophryne, Nectophryne, Nectophrynoides, Nimbaphrynoides, Oreophrynella, Osornophryne, Pedostibes, Pelophryne, Peltophryne, Pseudobufo, Rhamphophryne, Werneria, Wolterstorffina.

FAMILY HELEOPHRYNIDAE

Ghost Frogs. Frogs of mountain streams in southern Africa .  They have a belly that is similar to glass frogs.  The tips of their digits are expanded, and have webbed feet.  The tadpoles are unique in having no beak, having multiple rows of teeth, and having a large oral disc.  The adults have no ribs; they have teeth in the upper jaws, a pupil that is vertically elliptical.  Furthermore, the astragulus and calcaneum are fused, but only at the ends.

No fossil record.

Heleophryne.

FAMILY LEPTODACTYLIDAE (INCERTAE SEDIS)

Neotropical Frogs.  Mainly, these are frogs that occur in the tropics of the Americas , but some occur in the temperate zones of North and South America .  These have no structural synapomorphies, and likely is an artificial group of lineages.  Most of them have no ribs, have teeth on their upper jaws, 8 presacral vertebrae, and a terminal fusion of the astragalus and calcaneum.  They range from fossorial to arboreal, to aquatic taxa.  The developmental strategies are equally variable from complete metamorphosis to vivipary and terrestrial nests to aquatic development.

Common in Cenozoic of South America .

Adenomera, Alsodes, Atelognathus, Barycholos, Batrachophrynus, Batrachyla, Caudiverbera, Ceratophrys, Chaophrys, Crossodactylodes, Crossodactylus, Cyclorhamphus, Dischidodactylus, Edalorhina, Eleutherodactylus, Euparkerella, Eupsophus, Geobatrachus, Holoaden, Hydrolaetare, Hylactophryne, Hylodes, Hylorina, Ishnocnema, Lepidobatrachus, Leptodactylus, Limnomedusa, Lithodytes, Macrogenioglottus, Megaelosia, Odontophrynus, Paratelmatobius, Phrynocerus, Phrynopus, Physalaemus, Pleurodema, Proceratophrys, Pseudopaludicola, Scythrophrys, Somuncuria, Syrrhophus, Telmatobius, Telmatobufo, Thoropa, Vanzolinius, Zachaenus.

FAMILY MYOBATRACHIDAE

Australian Frogs.  Frogs of Australia with a few taxa in New Guinea and Tasmania .  They have no ribs, 8 presacral vertebrae, astragalus and calcaneum are completely fused, most have teeth on the upper jaw.  These range in habitat from desert to marshes and mountain streams.  They are fossorial to aquatic.  Eggs are laid in nests (terrestrial or aquatic).  Some brood the young in their stomaches. 

Miocene to te present

Adelotus, Arenophryne, Assa, Crinia, Heleioporus, Kyarranus, Lechriodus, Limnodynastes, Megistolotis, Mixophynes, Myobatrachus, Neobatrachus, Notaden, Philoria, Pseudophryne, Rheobatrachus, Taudactylus,Uperoleia.

FAMILY RHINODERMATIDAE

Darwin’s Frogs.  Frogs of the temperate forests of southern Chile and Argentina .  They have a distinctive behavior in which the males carry the larvae in enlarged vocal sacs.  They have an elongate snout (fleshy at the tip).  The hind feet are webbed, they have no ribs, and a weakly ossified skull.  They do not have ribs or teeth, they have 8 presacral vertebrae, horizontal pupils, and the astragalus and calcaneum were fused at the ends.  Mainly terrestrial and occur along cold streams in Beech forests.

No fossils are known.

Rhinoderma.

FAMILY HYLIDAE

New World Tree Frogs.  These arboreal frogs occur from temperate North America through tropical South America with taxa in Australia , New Guinea , Eurasia , Japan , and northern Africa .  They all have digits that terminate in “claws” and usually with toe pads.  The maxilla and premaxilla have teeth, one has teeth on the lower jaw.  Most are arboreal, though some are aquatic and others are fossorial.  The life histories are variable and range from fully aquatic larvae to fully terrestrial.  Some are carried about in vascularized pouches on the adults’ backs. 

Miocene to the present

Acris, Allophryne, Anotheca, Aparasphenodon, Corythomantis, Cryptobatrachus, Cyclorana, Duellmanohyla, Flectonotus, Gastrotheca, Hemiphractis, Hyla, Nyctimantis, Osteocephalus, Osteopilus, Phrynohyas, Phyllodytes, Plectrohyla, Pseudacris, Pternohyla, Ptychohyla, Scinax, Smilisca, Sphaenorhynchus, Stephania, Trachycephalus, Triprion.

Agalychnis, Hylomantis, Pachymedusa, Phrynomedusa, Phyllomedusa.

FAMILY MEGOPHRYIDAE

South Asian Frogs.  Generally frogs of the forest floor from west of the Wallace Line to Pakistan , including western China .  They have lost the ceratohyals as adults; intervetebral cartilage with ossification, and paddle-shaped tongues.  They have no ribs, 8 presacral vertebrae, astragalus and calcaneum fused at the ends, and indirect development of the tadpoles.

No fossil record.

Leptobrachella, Leptobrachium, Megophrys, Vibrissaphora.

FAMILY HYPEROLIIDAE

African Tree Frogs.  Mainly arboreal frogs of sub-Saharan Africa , the Seychelles , and Madagascar .  They have additional elements in the digits and claw-like terminal elements, a cartilaginous sternum, vertical pupils, no nuptial pad, and no ribs.  They vary from terrestrial to arboreal.  They lay eggs than may be terrestrial or in special structures above water.

No fossil record.

Acanthixalus, Afrixalus, Chrysobatrachus, Heterixalus, Hyperolius, Kassina, Leptopelis, Opistholhylax, Phlyctimantis, Tachycnemis.

FAMILY PSEUDIDAE

Paradox Frogs.  Aquatic frogs of tropical lowlands east of the Andes in South America and the Magdalena valley of British Columbia .  Adults have extra elements in the toes of the digits, which are ossified.  They have 8 presacral vertebrae, horizontal pupils, and a cartilaginous sternum.  The aquatic larvae are almost 4X longer than the adult frogs.

No fossils are known.

Lysapsus, Pseudis.

FAMILY CENTROLENIDAE

Glass Frogs and Leaf Frogs.  Arboreal frogs of the humid tropics of Central and South America .  The skin on the belly is clear and backs tend to be green.  They have broadened tips of their toes.  The astragulus and calcaneum are fused, teeth on the maxillae and premaxillae, and horizontal pupils.  Commonly, they care for the eggs, which are laid on plants above a stream, until they hatch.  Then, the larvae fall into the water.  No fossils are known.

Centrolene, Centrolenella, Cochranella, Hyalinobatrachium.

FAMILY MICROHYLIDAE

Microhylid Frogs.  Frogs with a wide distribution in the tropics and temperate zones of the world.  They are absent from most of Australia , the West Indies , and Oceania .  They have a distinctive appearance with pointed heads, round bodies, and small mouths.  Most of the synapomorphies can be interpreted as the retention of larval characters.  Most have no teeth or clavicles, and have a round (or horizontally oval) pupil.  They range from arboreal to terrestrial and nearly fossorial.  Most have small eggs and aquatic larvae.

Miocene to the present

Anodonthyla, Arcovomer, Asterophrys, Baragenys, Breviceps, Calluella, Callulina, Chaperina, Chiasmocleis, Cophixalus, Cophyla, Ctenophryne, Dasypops, Dermatonotus, Dyscophus, Elachistocleis, Gastrophryne, Gastrophrynoides, Gastrophyrne, Glyphoglossus, Hamptophryne, Hoplophryne, Hylophorbus, Hyophryne, Kalophrynus, Kaloula, Melanobatrachus, Metaphrynella, Microhyla, Myersiella, Nelsonophryne, Oreophryne, Otophryne, Parhoplophryne, Phrynella, Phrynomantis, Platypelis, Plethodontohyla, Probreviceps, Ramanella, Relictivomer, Rhombophryne, Scaphiophryne, Spelaeophryne, Sphenophryne, Stereocyclops, Stumpffia, Synapturanus, Uperodon, Xenobatrachus.

FAMILY DENDROBATIDAE

Poison Dart Frogs.  These brightly-colored arboreal frogs are found from Nicaraugua to Brazil in humid forests.  The brightly-colored taxa have alkaloid toxins associated with the skin.  Synapomorphies include a retroarticular process of the mandible, and carrying aquatic larvae on their backs.  They are diurnal and can exhibit complex social behaviors.  They live out their larval life history in the water-filled cups of bromeliads, to which they are carried and cared for by the female (sometimes male) parent.

Colostethus, Dendrobates, Mannophryne, Phyllobates.

FAMILY HEMISOTIDAE

Shovel-Nosed Frogs.  Burrowing frogs of tropical and subtropical savannah and scrub forests Africa .  They have smooth skins and have a highly ossified skull.  They burrow head-first and eat ants and mites. They have a vertical pupil, fused carpals and tarsals, and a notched tongue.  They have no teeth.  Females dig breeding chambers and lay large fertilized eggs which hatch.  How they get to ephemeral ponds for the larval part of the life history is still something of a mystery. 

No known fossil history.

Hemisus.

FAMILY ARTHROLEPTIDAE

Schreeching Frogs.  Rainforests of sub-Saharan Africa .  They have no defining structural synapomorphies.  Generally they are small frogs (<4cm long).  Some lay eggs in leaf litter and have direct development.  Others lay egges in water where they are guarded until they hatch (metamorphosis).

Arthroleptis, Astylosternus, Cardioglossa, Leptodactylodon, Scotobleps, Trichobatrachus.

FAMILY SOOGLOSSIDAE

Seychelle Frogs.  These small terrestrial frogs occur on only 2 small islands of the Seychelle Islands .  They have horizontal pupils and a number of characters that set them apart from other frogs.  Adults guard the young (one has direct development and the other has larvae that are carried by mother until the metamorphose.

Nesomantis, Sooglossus.

FAMILY RANIDAE

Riparian Frogs and True Frogs.  These frogs occur throughout the tropics and temperate zones of all continents except for most of Australia , Oceania , and temperate South America .  Most lack ribs, have teeth in their upper jaws, 8 presacral vertebrae, and an astragalus and calcaneum that are fused only at the ends.  The pupil is horizontal.  They range in habitat from fossorial to arboreal to aquatic.  Most of them have aquatic larvae as tadpoles. 

Miocene to the present.

Amolops, Anhydrophryne, Arthroleptella, Arthroleptides, Batrachylodes, Cacosternum, Ceratobatrachus, Conraua, Dendrobatorana, Dimorphognathus, Discodeles, Elachyglossa, Hildebrandtia, Hoplobatrachus, Micrixalus, Microbatrachella, Nannophrys, Nanorana, Natalobatrachus, Nothophryne, Nyctibatrachus, Occidozyga, Palmatorappia, Petropedetes, Phrynobatrachus, Phrynodon, Platymantis, Pyxicephalus, Rana, Staurois.

FAMILY RHACOPHORIDAE

Old World Tree Frogs.  These are arboreal frogs of the old world tropics (western Africa , Madagascar , India , southeast Asia and north to Japan).  They have extra elements between the terminal phalanges, toe discs, flattened bodies.  Also, they lack ribs, have 8 presacral vertebrae, tooth-bearing upper jaws, and astragalus and calcaneus that are fused at the ends.  They have aquatic tadpoles. 

No fossils are known.

Boophis, Callixalus, Chiromantis, Cryptothylax, Mantella, Mantidactylus, Philautus, Rhacophorus, Theloderma.

Prosalirus+, Triadobatrachus+