Classification of amphibians: 3 categories (2023)


In this article we will discuss about the classification of amphibians.

Subclass (1) Labyrinthodontia (bent teeth):

1. The name Labyrinthodontia derives from the structure of the teeth.


2. In cross section, the teeth show complete radial folding of the enamel surface. This type of teeth is also present in ripidistic crossopterygium.

3. The skull was huge and completely covered with skin bones and provided with heavily armored bony plates.

4. The roof of the skull consisted of the nasal, frontal and parietal bones.

5. The lower jaw consisted of as many as ten elements.


6. The vertebral skeleton consisted of a series of bony vertebrae, each vertebra having a neural arch and a zygapophysis, and their vertebral construction indicates that they are the ancestors of reptiles and higher vertebrates.

7. Ribs were present in the cervical vertebrae and in the proximal part of the caudal vertebrae.

8. The tail was absent, but short, powerful legs developed.

9. They were the first vertebrates to walk the earth.

Labyrinthodonts were present in late Paleozoic and Triassic fossils.

Labyrinthodonts were once considered an early group of tetrapods that are now considered a paraphyletic group.

The subclass Labyrinthodontia is divided into two orders.

Order (1) Anthracosauria; Order (2) Temnospondyl.

Order (1) antracosaurs (Carbono - Permian):


1. The pleural center was the larger element than the intercentrum.

2. Moderately large tabular bone of skull articulating with parietal bone.

The group became extinct at the end of the Permian and was represented by two groups (i) the aquatic embolomers, e.g. Paleoherpeton and the other, more terrestrial Seymouriamorph group which had a large ear notch and a single occipital condyle (e.g. Seymouria).

They had strong limbs and were able to walk. Intercentra were smaller than early anthracosaurs. Terrestrial anthracosaurs gave rise to reptiles at the end of the Carboniferous period.


Order (2) Temnospondyls (Carboniferous – Triassic):

1. The pleurocentrum was the reduced element, but the intercentrum was the dominant element in the center.

2. The tabular bone was small and did not make contact with the parietal bone.

3. Tendency of the skull to flatten and shrink due to bone loss.


4. Double occipital condyle.

5. There were semi-aquatic, heavy, short-legged predators.


Trematosaurus, Eryops (Abb. 7.33A), Rhinesuchus, Plagiosaurus, Cacops (Abb. 7.33B), Peltothorax, Gerrothorax.



Many authors such as Colbert (1955), Romer and Watson (1962), Young (1981), McFarland et al. (1985) created a separate order Ichthyostegalia for the first known tetrapods: Ichthyostega, Ichthyostegopsis and Acanthostega, but Duellman and Trueb (1986) placed them in different families: Ichthyostegidae for Ichthyostega and Ichthyoste gopsis and Acanthostegidae for the genus Acanthostega without creating an order. separately. Command.

One of the oldest known tetrapods is Elpistostege, found in the Upper Devonian of Canada. The known skull was among the Rhipidists and the oldest known tetrapod: Ichthyostega. Ichthyostega stensioei Saeve Soderbergh 1932 was found in 1931 in freshwater sediments from the late Devonian or early Cretaceous of Greenland.

It had a fish-like caudal fin supported by dorsal rays on the nerve spines of the caudal vertebrae. The sutures are inside the skull. At the back of the squamous and quadrojugal bones was a preocular and a subocular.

The creatures were about 100 cm long, and the jaws were equipped with strong and sharp teeth, which were used to hunt predators. They had a sideline system. They had a short snout, strong legs, and well-ossified rickety vertebrae (the vertebrae have two pairs of arcuate components; a larger anterior intermediate center and a smaller posterior center; the latter being the second "arc" component).


Subclasse (2) Lepospondyli (Carboniferous-Permian) (whorl of scales):

1. Lepospondyls arose in the middle of the Carboniferous, flourished at the end of the Carboniferous, and disappeared at the end of the Permian without leaving descendants.

2. They were small, less than 30 cm to 1 m long.

3. They had a lepospondylic vertebra (from the Greek lepos = scale; spondlylos = vertebra or vertebra in the shape of a shell or spiral).

4. The spiral in which the center ossifies around the notochord merges with the neural and hemal arches.

The subclass is divided into two orders (i) Aistopoda and (ii) Nectridians.


Order (1) Aistopoda:

Aistopods are represented by two or three genera. They were snake-like creatures with shrunken or missing legs and were likely aquatic amphibians. They vary from a few centimeters to about 1 m in length. The vertebrae numbered about 200. They were found in deposits in Mississippi and Pennsylvania.


Ofiderpeton (Abb. 7.33C).

Order (2) Nectrids:

The group was more of a salamander form. Two types of lineages are distinguished among the nectrids. One species was a limbless or nearly limbless snake with a long, pointed skull (e.g., Urocordylus). They were fully aquatic. The other group had small limbs, a flat body with horned skulls.

They were about 60 cm long (eg Diploceraspis).

Order (3) Microsauria:

The clade was yet another form of salamanders and was formerly classified among the aistopods and nectridians, but Duellman and Trueb (1986) considered them a separate clade because of the following characteristics: (i) Moderately elongated bodies with small, weak limbs, (ii) ) ) Three digits preserved on forelimbs and (iii) supratemporal on skull, but lost tabularly and interparietally (eg Euryodus).


Panchen (1972) and McFarland et al (1985) separated microsaurs from lepospondyls and proposed to consider them as a separate group. This group is also important, as some authors postulate that the group must be ancestral to salamanders and apods.

Subclass (3) Lissamphibia Haeckel, 1866 (Triassic—Recent) (Smooth Amphibian) (gr. smooth, smooth):


1. They are modern amphibians with smooth skin.

2. The vertebrae are monospondylic (meaning they want to have separate intermediate centers).

3. The skull is broad and the orbits are widened towards the cheeks and temporal regions.

4. Teeth are protruded (like fangs).

5. A columella and an operculum are present (secondarily absent in some taxa).

6. The amphibiorum papilla, a special sensory area in the inner ear, is present.


Lissamphibians are found in tropical and temperate parts of the world.

The subclass includes 3 existing orders.

Order (1) Caudata Oppel, 1811 or Urodela Latreille, 1825 [Upper Jurassic – modern] (Gr. caudates, tail; oura, tail + delos, visible) About 400 species.



1. Body of a lizard with a well-developed tail that helps in the development of the animal.

2. Different head.

3. The eyes are small and without eyelids, but in troglodytes (cave dwellers) eyes are absent (eg Proteus).

4. Teeth may or may not be present.

5. No eardrums, but salamanders can perceive sounds.

6. Many species have grooves on the sides of the body.

7. Water slides have a system of lateral lines.

8. There are two pairs of weak limbs (hind limbs are absent in Sirenidae).

Intern B

Mole parts:

1. The intestine forms several loops:

2. Breathing is usually done through external gills in the larval stage, but through the lungs and skin in adults. Lungs are absent in Desmognathus, where breathing is exclusively cutaneous and pharyngeal. Each lung is a simple bag-like structure (Fig. 7.34).

3. The heart is of the amphibious type, except in terrestrial lungs, except in plethodontids and permanently aquatic forms in which the interatrial septum and spiral valves are lost or reduced.

4. There are usually four pairs of aortic arches. Where gills persist in adults, accessory loops are present on arterial arches 3, 4, and 5. Figure 7.35 shows the arrangement of arterial arches in a larval and adult urodel.

5. Sirens have a ventricular septum.

6. The brain is relatively simple (Fig. 7.36). The cerebral hemispheres are extremely elongated. Visual lobes are comparatively small.

7. The columella in the middle ear is absent.

8. The kidney is of the opistonephric type.

9. The urinary bladder is not bilobed.

10. Elongated testicles usually show a segmental nature.

11. The ovary is an elongated structure.

12. The fallopian tube is tubular. The posterior portion is not expanded to form the uterine chamber.

hard parts:

1. In the skull, the cartilaginous elements are greatly reduced, being found only in the occipital region.

2. Vomer and palate merge into vomer palate.

3. Frontal and parietal are separated.

4. The ear notch and middle ear are absent.

5. Postorbital, jugal, postfrontal, and postparietal absent.

6. The vertebrae can be amphicella or opisthocele.

7. The shoulder girdle is simple and composed mainly of cartilage (Fig. 7.37A). Two coracoids overlap. The shoulder blades are ossified.

8. A y-shaped ipsiloid bone or epipubis is attached to the pubic bone (Fig. 7.37B).

9. Ribs are present.

Fertilization and development:

1. Fertilization is usually internal, but external in Cryptobranchoidea and presumably Sirenoidea. In internal fertilization, the male releases a seed packet (spermatophore) into the soil; it has a gelatinous base and a mass of sperm on top. Females collect this packet and store the sperm in the cloaca.

2. A phenomenon called pedomorphosis or pedogenesis is found in several families, which are recognized by the retention of larval features, including the lateral line system, true teeth in both jaws, gill slits, and external gills.

3. The larvae are generally aquatic, but some are exclusively terrestrial (Spelerpes fuscus).

4. Some species of Salamander and Mertensiella are ovoviviparous or viviparous.

Geographic distribution:

Mainly in temperate regions throughout the Northern Hemisphere and several in tropical regions of Central and South America.


Four suborders are provisionally recognized, including 9 living and 4 extinct families. Living families include 62 living genera with 352 species. McDiarmid (1993) reported the occurrence of 383 species in ten families. Pough, Janis and Heiser (2002) also listed 415 species and 10 families.

Suborder (1) Karauroidea Estes, 1981:

The characters are like Karauridae Ivanhnenko, 1978.

Family 1. Karauridae (Jura):

1. The angle is not fused when pre-articulating.

2. Teeth are pedunculated.

3. Flat skull.

4. The vertebrae are amphicellular.

5. Ribs have two heads.


Karaurus, the only genus present in the family, was collected in Kazakhstan, USSR.

Subordem (2) Sirenoidea Goodrich, 1930:

1. Eel-like aquatic salamanders.

2. They only have front legs, eyes without eyelids, and three pairs of external gills.

3. Hind legs and waist are completely absent.

4. They have reduced pterygoids and pre-pterygoids and a prominent Jacobson's organ.

5. The angular merges with the pre-articular. Fertilization is probably external.

6. The vertebrae are amphicellular.

7. Double-headed ribs.


The relationship is uncertain. Some authors assume that they evolved from some Hynobids.

It includes a single Sirenidae family.

Family 1. Sirenidae Gray, 1825:

1. Gill openings 1-3 pairs and 3 pairs of lamellae with outer fringes.

2. Front legs with 3 or 4 toes.

3. Hind legs and pelvic girdle absent.

4. Amphicele vertebrae.

5. Absent ypsiloid cartilage.

Contains 6 fossils and 4 living species of paedomorphs.

They are:

(i) Late Cretaceous and Late Paleocene Habrosaurus of North America.

(ii) Mermaid-3 gill slits on each side and 4 fingers; two types


Sereia Lacertina (mud eel) and S. intermedia.


Found in lakes and streams in the southeastern United States, from South Carolina to Tomaulipus and northeastern Mexico.

(iii) Pseudobranchus: recognizable by a pair of gill slits and 3 fingers; single species.


Pseudobranchus striatus.


southeast two United States.

Subordem (3) Cryptobranchoidea Dunn, 1922:

1. Aquatic, semi-aquatic and terrestrial.

2. External gills are absent.

3. The angular and prearticular bones of the mandible are not fused.

4. Amphicele vertebrae.

5. Single head ribs.

6. External fertilization.


They are found in eastern North America and Asia, including Japan, Korea, the Ural Mountains, China and Turkestan.


The suborder includes 2 living families with 11 genera and 35 species.

Family 1:

Hynobiidae Cope, 1860 (East Asian land salamanders)

1. Adults lack larval teeth, gills and gill slits and have eyelids.

2. Complete metamorphosis.


Hynobiids are found in Iran, China, Korea, Japan, the Ural Mountains and Siberia.


Contains 9 genera comprising 36 species.


(i) Hinobio:

body compressed laterally; lungs present; teeth in both rows; Feet can have 4 or 5 toes. 17 species. Found in Japan, Turkestan and Europe.


H. keyerlingii occurs in Europe, Syktyvkar in the Soviet Union. Other examples are H. naevius, H. lichenatus and H. nebulosus etc.

(ii) Onychodactylus:

Absent lungs. The larvae have a claw-like structure on their fingers and toes. mountain stream shapes; O. japonicus and O. fischeri. Both are found in Northeast Asia. Other genera are Ranodon, Pachypalaminus, Batrachuperus, Pachynobius, Paradactylodon and Salamandrella.

Family 2. Cryptobranchiidae Fitzinger, 1826 (The giant salamanders):

1. Adults don't have eyelids.

2. They are all paedomorphs and spend their entire lives in the water.

3. They have a pair of gill slits (absent in Andrias = (Megalobatrachus).

4. Incomplete metamorphosis.


Central China, Japan and parts of the eastern United States.


Contains 2 genera, including 3 living and 2 extinct species.


Andrias = (Megalobatrachus), 2 species are found in China and Japan. The Japanese giant salamander (A. japonicus) grows to 1.50 m in length. It is found in mountain streams in Japan. He has warts on his head and neck. It is the largest living amphibian.

The Chinese giant salamander (A. davidianus) is smaller and has warts on its head and throat. Occurs in the mountain stream of China.

Cryptobranchus (the Hellbender), found in the eastern parts of the United States, lives in mountain streams. It is a foot and a half long and has no external gills. There is one species and two subspecies. C. alleganiensis with C.a. Bishopi and C.a. alleganiensis.

Subordem (4) Salamanroidea Noble, 1931:

1. They are aquatic (newts and Congo eels, Amphiuma) or terrestrial (pletodons).

2. External gills in some species.

3. Males have 3 sets of cloacal glands.

4. Internal fertilization.

5. Absence of septomaxillary bones in the skull.

6. The angular merges with the pre-articular.

7. Vertebrae are usually opistostole.

8. Ribs have two heads.


They are found throughout the temperate Holarctic region and northern South America.


The suborder includes 6 living and 3 extinct families.

Family 1. Prosirenidae:

They are known from the Middle Jurassic to the Middle Miocene of Europe and the Early Cretaceous of North America.

1. Teeth are not spiked.

2. Cast end faces.

3. They were small aquatic salamanders or even fossils.


Prosiren, Albanerpeton, Nucusurus and Ramonellus.

Family 2. Batrachosauroididae:

They have been known since the late Cretaceous period of North America.

1. Teeth are pedunculated.

2. The premaxillae are paired.

3. They were aquatic and had reduced limbs.


Batrachosauroides, Opisthotriton, Prodesmodon.

Family 3. Proteidae Gray, 1825:

1. They have 3 pairs of gills with fringes and 2 pairs of gill openings.

2. The appendages are provided with 3 fingers and 2 fingers.

3. Teeth are pedunculated.

4. No baking.

5. Pigmented body and permanent larvae.

6. Pedomorphic aquatic salamanders.


The family includes two genera: (i) Proteus and (ii) Necturus. Proteus is found in Eastern Europe and Necturus in eastern North America.


2 genera including 6 living and 4 extinct species.


Proteus anguinus (The Olm) and Necturus (The Mud Pup). Necturus includes 5 species and one subspecies. N. maculatus (eastern half of the United States), N. punctatus (North and South Carolina).

The European elm (Proteus) is a salamander native to Europe. It is located in the Magdalena Cave near the Adelsberg Cave in Yugoslavia. They are usually viviparous, but if kept in a warm place (about 15°C) they sometimes lay eggs.

The fossil genera are Mioproteus and Orthophyia.

Family 4. Dicamptodontidae:

1. They have developed limbs and eyelids.

2. Larvae have 4 pairs of gill slits.

3. Teeth are pedunculated.

4. Semiaquatische Salamander.


Northwest United States.


Two living genera including 8 living species.


Dicamptodon e Rhyacotriton.

Family 5. Scapherpetontidae:

They have been known since the late Cretaceous period in southern western Asia.


Eoscapherpeton, Horezmie, Scapherpeton.

Family 6. Amphiumidae Gray, 1825 (Congos or Congo eels):

1. Semi-aquatic or aquatic forms.

2. Eel body and atrophied limbs.

3. They do not have external gills, but larval gills and well-developed lungs.

4. Teeth are pedunculated.

5. They don't have eyelids.


southeast two United States.


There are three living species and three extinct species.


Proamphiuma (Late Cretaceous of North America); Amphiuma means A. tridactylum etc.

Family 7. Graue Salamandridae, 1825:

1. Pre-vomerine teeth arranged in an S-shaped row on each side of the parasphenoid.

2. Mainly opisthoceles vertebrae, but some anficellae.

3. Septomaxillae, lacrimal sacs and ipsiloid cartilage are present.

4. Larvae have 4 pairs of gill slits and large external gills.

5. Adults with normal gills; lungs present.

6. Eyelids present.

7. Terrestrial and aquatic salamanders.


They are found in North America, Europe, North Africa, East Asia and Asia Minor.


49 living and 15 extinct species are included in 15 genera.


Archaeotriton (late Oligocene and early Miocene of Czechoslovakia)

Brachycomus (Early Miocene), Chioglossa (Spain and Portugal)

Martensiella (Greece, Turkey and Western Caucasus)

Pachytriton (Southeastern China), Saltimandra (Europe and Western Asia), S. salamander (Central and Southern Europe, Western Asia).

Salamandrina (Northern Italy and Liguria), Taricha (North America), Triturus = Triton, 12 species (Europe, Asia Minor to the Caspian Sea, Ural Mountains).

The Zagros newt (Neurergus) occurs in the Zagros Mountains of Ian (Fig. 7.38A). It has 3 types. N. crocatus is found in the northwestern provinces of Iran and Kurdistan. N. microspilatus is found in the province of Lorestan. The habitat of these newts is closely associated with shallow, cool and clear mountain streams and nearby vegetation.

In the breeding season, mating takes place near water. Females lay their eggs in the water. After a few weeks, the larvae will swim in the water. The duration of metamorphosis from larvae to adults is 2 months.

Tylototriton, 7 species (Darjeeling district of West Bengal in southern China, Ryukyu Islands). Tylototriton verrucosus (unique Indian urodels).

T. andersoni is found on the islands of Okinawa in the Loochoo archipelago.

Tylototriton wenxianensis is found in China and has gradually ceased to be collected for medicinal purposes. It was once a common food available in local markets, but their numbers are now greatly reduced.

The Chinhai salamander (Echinotriton chinhaiensis) is found in montane forest areas east of Ningoo, Zhejiang, China (Fig. 7.38B). The salamander is fully terrestrial and lays eggs on land, near ponds. Larvae develop in ponds (Cai and Fei (1984); Xie et al., (2000).

Family 8. Ambystomatidae Hallowell, 1858:

1. The angle is used with the pre-articular.

2. The prejaws are paired and enlarged.

3. Amphicele vertebrae.

4. Teeth are pedunculated.

5. The palatal teeth are arranged in an almost straight transverse line.

6. Fertilization takes place internally by male spermatophores.

7. Neotenic forms with gills and lungs.

8. Present eyelids.

9. Terrestrial salamander with aquatic larvae.


United States and Mexico.


32 living species are contained in 2 living genera.


Ambystoma (= Amblystoma), from Alaska to Mexico, along northern Asia, southern China. Ambystoma persimile, the only non-American species, is found in the highest mountains of Thailand and high in Myanmar. Ambystoma usually lays eggs in water.

Larvae have a broad body with caudal fins. A. tigrinum occurs from New York to central Mexico. It has a depressed head with a wide mouth. The body is dark brown or bluish brown with numerous spots. The belly is grayish. The eyes are golden brown. The famous larva of A. tigrinum is the axolotl.

In spring, they lay eggs in the water. A. opacum, the European spotted salamander, is found from New Jersey to Florida and Texas. It can be recognized by its wide body with a rounded snout, gular crease in the neck region, hind legs larger than the front ones, black pupils in the eyes and purplish-black body. A. opacum lies on the ground in autumn. After laying, the female protects the eggs by enveloping them.

Ryacosiredon, found in the streams and rivers of the southern Mexican highlands. There are 4 types.

Family 9. Plethodontidae Grade, 1858:

1. Lungless salamanders. They depend entirely on skin respiration for all gas exchange. The skin allows many environmental pollutants to pass through.

2. Present eyelids.

3. The teeth are pedicalized.

4. Vomerine teeth forming dental plaques on the parasphenoid.

5. The vertebrae are opistostole.

6. Size small to medium (4-30cm).

7. Are they aquatic or terrestrial.


North America, Central America, most of South America and Southern Europe.


There are 27 generals and 265 species.



Contains 11 species ranging from eastern Canada to Kansas (eg Desmognathus fuscus). Eurycea and Cyrinophilus (eastern North America) are fully neotenic. Nototriton (Guatemala to Costa Rica); Bolitoglossa and Chiropterotriton occur from Mexico to South America.

Plethodon is found in the eastern and western United States and can be found under logs or in rock crevices during the day. Typhlomole, Texas blind salamander, is found in burrows and deep wells in Texas, USA and has only one species, T. rathbuni. Hydro mantes is found in Italy and part of southern France.

Systematic condition of Urodela:

The systematic status of urodelas is disputed due to their particular anatomical organization. Anatomically, urodels form a transitional group between fish and amphibians. On the one hand, they show structural similarities with fish, and on the other hand with amphibians.

relationship with fish:

Urodeles exhibit the following fish characteristics.

These are:

(1) Presence of an immovable fixed tongue.

(2) Lateral line sense organ is present.

(3) Gills are present.

(4) The circulatory and excretory systems share many similarities.

(5) The tympanic membrane is absent.

In addition to these typical fish characteristics, urodels have some similarities with crossopterygians.

The similarities are:

(1) The presence of gills in the skin,

(2) similar straps,

(3) Similar venous system,

(6) The first spinal nerve has no dorsal root and

(7) dieYpsilonThe Urodele bone is comparable to the epipubic bone of Dipnoans. The similarities with fish in general and with Crossopterygia in particular speak for their phylogenetic relationship.

relationship with amphibians:

Urodelae are included in the order Urodela under the class Amphibians. This fact need not be taken into account, since the organization of the brain, circulatory system, skull and viscera is typically amphibious in nature.

Among amphibians, Urodelians must be considered a more primitive group than Apodans and Anurans, because the square position and the gait justify the truth. The primitive characteristics of urodels are due to the retention of larval characteristics.

Within the Urodela Order there is one level of organization:

Classe I:

Urodeles with perennial gills (due to their whitish state), eg Necturus, Proteus and Siren.

Class II:

The absence of gills and the presence of only gill slits in adults (derothematous disease) represents the transitional stage, for example Amphiuma.

Grade III:

Absence of gills and gill slits in adults (cauducibranchiate condition) are the most advanced forms, e.g. B. Andrias, Salamander, Triturus.

Order (2) Gymnophiona Rafinesque, 1814 (nickname, Caecilia) (Jurassic – modern times) (Greek gymnos, naked, ophioneos, snake; a, without sheath, foot) About 165 species.

General characters:

A. External features:

1. Digging, elongated, worm-like creatures without limbs.

2. Body smooth, slimy, and segmented by a series of annular grooves in which small granular skin scales are embedded, in many caecilians (eg, Uraeotyphlidae, Typhlonectidae, and Caeciliidae. Scales are absent in the Indian genus Cegenophis and in the American one Siphonops , Typhlonectes, Chthonerpeton and Bdelphis.

3. The tail, if any, is short; conical but flattened tail of the American genus Typhlonectes.

4. Reduced eyes without skin-covered eyelids or jaw.

5. A peculiar sensory tentacle resembling a conical fin which extends between the nostril and the eye and is housed in a small pit on each side of the head. The pits receive secretions from harder and more well-developed glands. The tentacle is probably a chemosensory organ and helps the animal detect the presence of prey in subterranean conditions.

6. A single protractile medial copulatory organ (phallodeum) in males may protrude through the cloaca, evidence of internal fertilization.

7. Both tympanic membrane and tympanic cavity are absent.

8. The tongue merges with the floor of the oral cavity.

B. Internal Characters:

(a) Hard parts:

9. Amphycellus whorl with persistent notochord and number varying from 200 to 300.

10. No sternum. Pectoral and pelvic girdles are absent.

11. Solid and compact skull and fusion of some elements, p. Upper jaw and palate in the maxillopalatine.

12. Large and broad upper jaw. A prefrontal is present.

13. Scaly fused with the quadratojugal.

14. Separated frontal and parietal.

15. Columella (stirrup) absent or large and stirrup-shaped.

16. Teeth in the premaxilla, maxilla-palatine, vomer and dentary.

17. The orbit is small, surrounded by post-frontals.

(b) Soft parts:

18. Straight in some ways.

19. Conus arteriosus does not have a spiral valve and has one or two rows of valves.

20. Asymmetrical lungs; only the right part well developed.

21. Only the pulmonary and systemic arches persist. The carotid artery originates from the systemic.

22. There is a ductus arteriosus (lateral vessel that connects the systemic and pulmonary arches).

23. Presence of functional Müllerian ducts in males.

24. Oblong paired ovaries in the shape of a sac.


25. Fertilization can be external (eg rhinatrema) or internal (eg cecilia (Fig. 7.39A and B), Hypogeophis, Ichthyophis (Fig. 7.40).

26. The eggs are large and yolky.

27. Cleavage is meroblastic.

28. Most primitive Caecilians are oviparous, but some advanced Caecilians are viviparous (eg Typhlonectes). As the eggs are laid in the ground, the embryos grow with the yolk.

29. Free-living larval stages are observed in the primitive family Ichthyophidae.

30. Ichthyopis burrows near a stream and the larvae hatch and enter the stream.

31. Ichthyophis larvae are characterized by the presence of long gills with three-pointed fringes.

32. Ichthyophis larvae have a lateral line and dentition of the adult type.

33. Ichthyopis glutinosus laying in Ceylon (Sri Lanka) occurs from July to September, but Seshachar (1936) recorded December to March.

34. In some Apodans there is a phenomenon called tachygenesis (which is the rapid elimination of ancestral traits through the acceleration of developmental stages).

History of Fossils:

Due to the subterranean lifestyle, no fossil representatives have been found, except for the only fossil of Apoda Eoceacilia collected in western North America in the Lower Jurassic (Pough et al., 2000).


Caecilians are generally found in wet, damp areas under rocks and rocks, with the exception of Typhlonectes, which is a river dweller. Chthonerpeton and Siphonops are found where human waste is dumped. Some Caecilians, such as Ichthyophis and Schistometopum, live on cleared land used for crops such as tea and coffee plantations and rice paddies.

It is generally difficult to find in its natural habitats. They can be seen when the rain comes. According to Honegger, Caecilians prefer sandy soils that can be wet or completely wet. He reported that all specimens were found at depths of 20 to 30 cm below the ground.


Apodans feed on earthworms, arthropods and small vertebrates, including snakes.

Geographic distribution:

Gymnophionas are restricted to the tropics, with the exception of Europe, North America, Madagascar and Australasia. Exceptionally, they are common in the Seychelles islands.


Neiden (1913) reported 19 genera and about 55 species. He summarized all the Caecilians in a single family Caecilidae. Recently, the American scientist E. H. Taylor (1969) reviewed the entire group.

He divided them into 4 families:

(i) Ichthyophidae

(ii) Cecilian

(iii) Typhlonectidae e

(iv) Scolecomorfidae.

Duellman and Trueb (1986) recognized 6 families comprising 34 living genera and 162 living and one extinct species.

Pough et al., (1996) classified caecilia into 6 families comprising 165 species.


Nassbaum (1979) considered the subfamily Uraeotyphlinae of the family Uraeotyphlidae as the sister group to Cecilia superior (i.e., Scolecomorphidae, Caeciliidae, and Typhlonectidae) and the Ichthyophiinae as the sister taxon to Uraeotyphlinae and Cecilia superior. But Frost (1985) proposed classifying Uraeotyphlinae as a subfamily under Ichthyophidae.

Family 1. Ichthyophidae Taylor, 1958:

The body length is about 500 mm. They have a tail and a subterminal mouth. The opening of the tentacle is between the eye and the nostril. Some are gray or black; others have clear stripes on the sides. Aquatic larvae have one or two gill openings.

Geographic distribution:

India, Sri Lanka, Philippines, Sumatra and Borneo.


2 genera and 36 species are included.

Caudacaecilia (5 species, Malaysia, Philippines, Sumatra and Borneo) and Ichthyophis (30 species; India, Sri Lanka, Philippines and Indonesia). I.sikmensis = (I.glutinosus) (Darjeeling, Sikkim).

Family 2. Uraeotyphlidae Nogueira, 1979:

The body length is about 300 mm. They have a tail and a ventral mouth. The opening of the tentacle is below the nostril. They are dull gray to brown in color. Oviparous.

Geographic distribution:

South India, Sri Lanka.


A genus with 4 species, for example, Uraeotyphlus. Uraeotyphlus malabaricus (South India).

Family 3. Scolecomorphidae Taylor, 1969:

The body length is moderate, reaching about 440 mm. They do not have a tail with a sunken mouth. The back of the body is black or brown. Possibly viviparous.

Geographic distribution:

Mainly from Cameroon and Tanzania.


A genus includes 5 species, eg Scolecomorphus = Bdelphis.

Family 4. Caecilidae Gray, 1825:

The body length varies between 100 mm and 1500 mm. They have no tail and a sunken mouth. The opening of the tentacle is in front of the eye. Most are matte gray or black, but some are striped. oviparous and viviparous.

Geographic distribution:

They are restricted to the tropical regions of Central and South America, sub-Saharan Africa, India and the Seychelles.


There are 24 living genera with 89 living species. Some of the genera are Caecilia (northern South America and eastern Panama); microcecilia (Guatmala); Parvicaecilia (Northern Colombia); Afrocaecilia (Kenya and Tanzania); Brazilotyphlus (Brazil); Dermophis (southern Mexico to Colombia); Cegenophis (South India); geotrypets (Ethiopia and southwestern tropical Africa); Grandisonia (Seychelles); herpelos (tropical West Africa); Hypogeophis (Seychelles); Indotyphlus (Maharashtra, India); Praslinia (Seychelles); Siphonops (tropical South America).

Family 5. Typhlonectidae Taylor, 1968:

The body length is more than 700mm. They don't have a tail and their mouths are sunken. The rear body is laterally compressed. The color of the dorsal part of the body varies from gray to brown or bluish-black. The small tentacle is behind the nostrils. They are fully aquatic. viviparous.

Geographic distribution:

They are found in South America.


There are 4 genera with 22 species.

Chthonerpeton (Argentina and Brazil); nectocaecilia (Amazon basin); Potomotyphlus (South America); Typhlonectes (South America).

Family 6. Rhinatrematidae Nussbaum, 1977:

The body length is about 300 mm. They have a tail and a mouth at the end. The tentacle borders the eye. Yellow stripes are present on the lateral side of the rhinatrema.

Geographic distribution:

South America.


There are 2 genera with 9 species. Epicrionops (Venezuela to Peru); and Rhinatrema (northeastern South America).

Key to Gymnophiona genera in India(Revised by E.H. Taylor, 1961):

1. Tentacles closer to the eye than the nostril or the same.

Tentacles closer to tip of snout than eye.

2. Transverse Anal Orifice; the cone-shaped tentacle, flush with a line between the eye and nostril; no tail; 144 vertebrae; spleen teeth present.

……………. Indotyphus Taylor, 1960.

Anal longitudinal aperture; tentacles on edge of lip below line between eye and nostril; present tail; vertebrae no more than 125; Splenic teeth present or absent.

……….. Ichthyophis Fitzinger, 1826.

3. Parietal and squamous bones of skull separated by gap. Fin-shaped with tentacles almost directly below the nostril near the mouth; closed circular path; Tail region wider than the body.

……….. Uraeotyphlus Peters, 1879.

The plate and parietal bones form a common suture.

4. A single row of teeth in the lower jaw. without splenials

………….. Gegenophis Peters, 1879.

Two rows of teeth on the lower jaw; eyes covered by bones; conical tentacle slightly behind the nostril, but below its lower level.

……………. Herpele Peters, 1879.

The formerly known Herpele fulleri (Assam) is now transferred to the genus Gegenophis fulleri.

Key to the Indian species of Ichthyophis[The E.H. Taylor, 1961]:

1. A lateral cream or yellow stripe on each side of the body, from head to tail;

……………… 2

No cream or yellow lateral stripe on the side of the body; usually less than 20 spleen teeth on each side. 4

2. Abdomen evenly lavender to lead; Position of tentacle variable.

……. 3

abdomen with a wide white or yellow ventral median stripe; tentacles close to the lip and almost equidistant from the eye and nostril; transverse folds 245 - 275; Tail length 56.5 times greater in males and 60 times greater in females in relation to total body length Annandale tricolor, 1909


Maddathori, Ghats Occidentales, Cochin.

3. Tentacles almost equidistant from eye and nostril; yellow lateral band widens in the neck region; Transverse folds around 240-293

……………… Beddomii Peters, 1879



tentacles close to the lip, much closer to the eye than to the nostril; side stripes in the neck area no longer wider; Abdominal folds around 300 – 400.

…………sticky guy

4. Number of tail folds less than 10; the body bends less than 300; Tail total length about 50 times. 9-10 spleen teeth on each side; Strands sparse or anterior.

……………sikkimensis Taylor, 1960



number of folds on the tail more than 10, on the body usually more than 300; Tail length less than 30 times.


5. Splenic teeth 4 or less on each side; 18 transverse folds on the tail; vertebrae 116; abdominal light; Total length 330mm.

………………….peninsularis Taylor 1960


Malabar Coast. splenic teeth 5 or more per side in adults; 14 – 18 tail folds.


6. Lower teeth 26-28; tail in full length about 23.5 times; vertebrae 111; creamy or yellowish belly; Total length 494mm.

……………. Malabaricus Taylor, 1960


Maduvangard, Travancore.

7. Lower teeth 20 – 22; splenic teeth 9 – 9; 14 tail folds; total tail length 25.6; brownish abdomen; Total length 390mm.

………………. Bombayensis Taylor, 1960


Waghai, Surat, Gujarat.

Very large lower teeth 17-17; plenary day 10-10; 18 tail folds; transverse folds 356-364; scales up; dark lavender brown abdomen; total length 295mm,

…………Taylor Subterraneans, 1960


Kottayam, Travancore.

Number of species of the Indian Cecilian:

21 species of caecilians in 4 genera and 3 families known so far from India are concentrated mainly in the Western Ghats, but also in the Eastern Ghats and NE India (Ravichandran, 2004).

20 species and 3 genera are endemic to India, 13 of these endemics are restricted to the Western Ghats and most species are found in the Kerala side of the southern Western Ghats. The indigenous species represents 12.73% of the 165 species of the group recorded worldwide.

systematic position:

The systematic position of Apodane is not correctly determined, since its fossil representatives are not enough due to the underground way of life. Sarasin supported Cope's view that its closest relatives are 'Amphiuma' in Urodela. They considered that Amphiuma represented a neotenic form of the Caeciliidae, which they subdivided into Amphiumidae and Caecilidae, both under the suborder Urodela.

Your conclusion is based on the following points:

(i) In both cases, the mode of oviposition is the same.

(ii) Residual tentacle structure occurs in Amphiuma.

(iii) An ethmoid is present in Amphiuma as in Caecilidae.

But Davidson (1895) did not support the above claim, stating that the ethmoid bone is not found in Amphiuma.

Gadow, H. (1901) considers that the Caecilians retain both primitive and specialized characters.

The primitive characters are:

(i) Scales of skin encrusted with lime, lembrando lepospondyli from the Carboniferous.

(ii) Retention of postfrontal bone (Ichthyophis), ectopterygoid (Hypogeophis), lacrimal bone and gill slits.

These primitive features suggest that apodans should not be included with other groups of amphibians. This group is more primitive than Urodela or Anura.

According to H. H. Newman (1939), highly specialized for a burrowing life and decidedly degenerate in many respects, apods are considered the most primitive modern amphibians.

They resemble other amphibians in the structure of the heart, notably the cone arteriosus in the heart, the organization of the brain, the absence of the tympanic cavity and the layout of the urogenital system.

But they are distinguished from other groups of amphibians by the absence of limbs, the presence of hairs on the skin, the presence of ductus botalli and copulatory organ and a large macrolecitic egg with a meroblastic slit, and the absence of gill-breathing larvae.

They also have some special characteristics due to the absence of limbs and waists, reduced eyes, presence of the retractable sensory tentacle and the carotid artery originating from the systemic.

Due to the above features, recent herpetologists such as Noble (1931), Colbert (1955), Coin and Goin (1960), Romer and Watson (1962), Young (1981), McFarland et al., (1985), Duellman and Trueb ( 1986)), Pough et al., (1996) and Kardong (2002) placed apodans under a separate order Gymnophiona (Apoda, Caecilia).

Superorden Salientia Laurenti, 1768 (L. hervorstehend, springend + ea, sufijo pi.):


1. Primitive crests have a short tail.

2. In frogs, the caudal vertebrae are fused together to form a rod-shaped structure called the urostyle.

3. The proximal tarsal elements are elongated.

4. Teeth are absent from gums in most forms except one species.

5. The pterygoid usually has three rays.


Triassic and Anurian Triadobatrachus.

Order (3) Proanura:

The characters are similar to Protobatrachidae.

Family Protobatrachidae:

This family is represented by a Early Triassic skeletal cast from Madagascar.


1. The skull was broad and frog-like, with large eye sockets.

2. Short back.

3. The ilium extends forward.

4. There is no urostyle due to fusion of posterior vertebrae.



Order (4) Anura Rafinesque, 1815 (Salientia) [Jurassic – Modern] [Gr. an = sin + oura = tail] About 3850 species.


Preserved modern toads and frogs are included in this order.


1. Frogs are small, powerful, four-legged animals.

2. The post-anal tail is missing.

3. The hindquarters have more than 4 segments and help in the long jump.

4. Well-developed eyelids.

5. Pronounced tympanic membrane.

6. Tongue may be present or absent (family Pipidae).

7. Wide mouth and large eyes set well in front of the head, allowing binocular vision.

8. No trace of external gills or gill slits.

Intern B:

hard parts:

1. Missing teeth in the jaw.

2. The frontal and parietal bones combine to form a single bone, the frontoparietal.

3. The pterygoid usually has three rays and the parasphenoid has posterior lateral wings.

4. The vertebral column consists of 5-9 presacral vertebrae.

5. Vertebrae always have zygapophyses and transverse processes, except the first atlas.

6. The post-sacral vertebrae are fused into one rod, the urostyle.

7. The tibia and fibula (= talus and calcaneus) are fused at least proximally and distally.

8. The ilium is elongated and extends well forward.


1. Fertilization is external, with the exception of Ascaphus, Eleutherodactylus and Nectophrynoides.

2. Reproductive behavior is associated with vocalizations, mainly in males.

3. Most anurans reproduce only during or shortly after a rain, laying their gelatin-encapsulated eggs in ditches or ponds filled with water.

4. Some species lay eggs on land but have aquatic tadpoles. .

5. Farm eggs directly evolve into frogs.

6. Many adult frog species demonstrate parental care by protecting or transporting eggs or tadpoles.

7. The tadpoles of some frogs are herbivorous, filter-feeding, and some are carnivorous.


All over the world, except in extremely cold and dry parts.

fossil history:

Beginning in the Jurassic of Madagascar, Europe, North and South America, the fossil record extends into the Pleistocene.


Noble (1922, 1931) based his classification of frogs mainly on the nature of the intervertebral joints, derived from the work of Nicholls (1916). The Anuran classification here includes 21 living families and one extinct family with 301 living genera with 3438 species (Duellman and Trueb, 1986). Pough, Janis and Heisor (2002) mentioned 4300 species in 27 families.

Family 1. Liopelmidae Mivart, 1869:

1. The most primitive frog.

2. The vertebrae are amphicellular.

3. Interdorsal and interventral remain cartilaginous.

4. Nine free presacral vertebrae.

5. Muscles that move the tail are present, although the tail is not found.

6. No drum.

7. Semi-aquatic, aquatic or terrestrial frogs.


New Zealand and Northwest United States.


The family contains two living and two extinct genera.


Liopelma, a genus endemic to New Zealand, includes three species. Small, grayish, sometimes speckled with brown, yellow or pink. Occurs in the mountainous highlands of New Zealand. They lay eggs in moist soil and the frog can develop inside the egg.

Lyopelmid frogs are very secretive and rare. Of the three species, the Archey frog (Liopelma archeyi) is in decline in the Coromondal Range and Tapu Ridge. Another species, L. hochstetteri, is also more or less available in New Zealand hatcheries.

Known as the "bell frog", Ascaphus comprises a single species and has a cloacal extension that appears to function as an introducer organ during copulation. They are found in the cold mountain streams of western North America. A. truei is 3–10 mm long.

Internal fertilization:

The extinct genera are Notobatrachus (Late Jurassic of Argentina) and Vieraella (Jurassic of Argentina).

Family 2. Discoglossidae Günther, 1859 (groove and thrust washer):

1. Free sacral vertebrae with biconvex center.

2. Pre-sacral vertebra always 8.

3. Opisthoceles-Wirbel.

4. Tongue and eyelids present.


They are found in Eurasia, the Philippines and Borneo.


5 living genera contain 14 species and 8 extinct genera contain 11 species.


Alytes (Western Europe), 2 species, A. obstetricans is known as the midwife toad. A. cisternasi is also called the Spanish midwife toad. Baleafrysia (Spain, Balearic Islands), 1 species Bombina (= Bombinator) [Europe, Turkey, Western USSR and Eastern Asia), 6 species, B. igneus (fire-bellied toad) is restricted to northern Europe.

They can be identified as dark black or olive on the upperparts and olive black or orange on the underparts.

Males are smaller than females and have internal vocal sacs. Discoglossus can be recognized by an indistinct tympanic membrane. Round or triangular pupil, long legs, conical head and smooth, shiny skin, 3 species restricted to southern Europe and northern Africa. Barbourula is found in northern Borneo and the Philippines.

Family 3. Rhinophrynidae Günther, 1859, is known as the "Mexican digging frog", known for its robust body, smooth skin, short limbs and small head. The well-developed inner metatarsus is used in construction. 1 species, Rhinophrynus, Texas and Mexico to Costa Rica.

Family 4. Palaeobatrachidae, (5 extinct genera). Examples Palaeobatrachus (Europe), Albionbatrachus (England), Lithobatrachus (Europe), Pliobatrachus (Germany).

Family 5. Pipidae Gray, 1825:

1. The pre-sacral opisthocoele vertebrae are 5 to 8.

2. The sacrum fused with the coccyx (urostyle).

3. Lack of tongue, hence the name Aglossus toad.

4. Poorly developed or absent eyelids.

5. Ribs free in larva, but attached to diapophysis during metamorphosis.

6. Some species of Pipa have aquatic larvae. A direct development is observed in some other species of Pipa.

7. Specialized aquatic frogs.


They are found in Africa (sub-Saharan) and South America.


30 living species are contained in 4 living genera. 6 extinct genera were also reported.


Cordicephalus (Cretaceous Israel); Eoxenopoids (Upper Eocene or Oligocene of South Africa); Hymenochirus (4 species found in tropical Africa); Pipa (7 species; Venezuela to Brazil and Peru, eastern Panama). Pseuhymenochirus (West Africa), 1 species; Saltenia (Late Cretaceous of Argentina); Shomronella” (Lower Cretaceous of Israel); Thoraciliacus (Lower Cretaceous of Israel); Xenopus (Sub-Saharan Africa, 14 species).

Xenopus is used to diagnose pregnancy in humans. After injecting the patient with urine, the frog responds by spawning within hours. Xenopus laevis is known as the clawed frog. The three inner rear fingers form black horn claws. Other species are X. mueileri, X. calcaratus, X. tropicalis, etc.

Xenopus laevis spends its entire life in an aquatic environment and may question the meaning of "amphibian" (it spends its life in two different environments).

Family 6. Pelobatidae Bonaparte, 1850 (shovel toads):

1. 8 presacral vertebrae.

2. The presacral vertebrae are evenly procoelic.

3. Sacrum fused to the coccyx (monocondylar joint with coccyx) in Megophriines.

4. Arciferal pectoral girdle (with superimposed procoracoid cartilages) with cartilaginous omostero and sternum.

5. Protractile tongue.

6. Totally fused talus and calcaneus and three tarsals.


Pelobines are found in Europe, West Asia, North Africa, North America to Mexico. Megophrines (about 80 species) are restricted to India, Sri Lanka, western China and the Philippines.


3 subfamilies are recognized, two of which are alive and one extinct. Two living subfamilies contain 9 genera, including 83 living species. The extinct subfamily includes three genera.


Subfamily 1:

Eopelobatinae include (i) Aralobatrachus (Cretaceous of Uzbekistan) (ii) Eopelobates (Early Eocene to Early Oligocene of North America) and Kizylkuma (Cretaceous of Uzbekistan).

Subfamily 2:

Megophryninae contains 7 genera. Atympanophrys (1 species, China); Brachytarsophrys (1 species, southwest China, Myanmar and Thailand); Leptobrachella (6 species, Borneo) and Leptobrachium (11 species; India, southern China, Philippines, Sunda Islands to Bali).

In India, Leptobrachium is represented by a single species; L. hasselti recorded from Khasi Hills. Leptolalax (4 species, southern China, Malaysia and Borneo); Megophrys (21 species; Southeast Asia, including India); Scutiger (29 species; from India to southern China) and Megophrys are represented in India by 4 species, namely M. parva, M. lateralis, M. monticola and M. boettgeri. Megophrys occurs in W. Bengal, Arunachal Pradesh, Assam and Sikkim. Scutiger occidentalis, S. sikimmensis are found in Jammu and Kashmir, Sikkim and West Bengal. Megophrys monticola nasula is known as the horned frog.

Subfamily 3:

Pelobatinae includes 3 genera, one of which is extinct. macropelobates (Mongolian Oligocene); Pelobates (4 species, Europe, West Asia, and Northwest Africa) can be recognized by having a cupped inner tarsal tubercle, webbed fingers, and an absence of tympanic membrane. P. fuscus insubricus (northern Italy), P. syriacus (Asia Minor). Scaphiopus (6 species, North America and Mexico) recognized by the subgular vocal sac and hidden eardrum.

Family 7. Pelodytidae Bonparte, 1850:

1. 8 presacral vertebrae with procelous centre.

2. Archiferous pectoral girdle with a cartilaginous omosterum and a bony sternum.

3. The sacrum is not fused to the coccyx and has a bicondylar articulation with the coccyx.

4. Small terrestrial frogs with aquatic larvae.


They are found in Western Europe and Southwest Asia.


Some authors such as Noble (1924) placed Pelodytes in the Pelobatidae family. Boulenger (1899) and Noble (1924) found that Scaphiopus, Pelobates and Pelodytes are closely related.


Two extinct genera and one extant genus with two extant species.


Miopelodytes (Miocene of the USA); Pelodytes (2 species, Western Europe and Caucasus). Pelodytes is known to lack the tarsal digging spur; Eardrums not fully implanted and long hind legs with frog-like fingers. P. punctatus (France and Portugal).

Family 8. Myobatrachidae Schlegel, 1850:

1. 8 presacral vertebrae.

2. Arciferal pectoral girdle with cartilaginous omosternum (absent in myobatrachus and notads) and sternum.

3. Astral gall and calcaneus fused proximally and distally, and two tarsals.

4. Aquatic and terrestrial frogs.


They live in Tasmania, New Guinea and Australia.


The family includes two subfamilies, 20 living genera and 120 species.


Adelotus (1 species, Australia); Heleiporus (6 species, Australia); Kyarranus (3 species, Australia); Lechriodus (4 species, New Guinea, Australia); Limnodynastes (12 species, Tasmania, New Guinea and Australia); Megistolotis (1 species, Australia); Myxophys (4 species, Australia); Neobatrachus (7 species, Australia); noted (3 species, Australia); Philoria (1 species, Australia). The ten genera above belong to the subfamily Limnodynastinae.

The other subfamily Myobatrachinae includes 10 genera. These are arenophrines (1 species, South West Australia); Assa (1 species; Australia); Crinia (13 species, Australia); Geocriny (5 species, Tasmania, Australia); Myobatrachus (1 species, Australia); Paracrinia (1 species, Australia); Pseudophryne (10 species, Tasmania, Australia); Rheobatrachus (2 species, Australia); Taudactylus (5 species, Australia); Uperolea (18 species, Australia). A fossil frog was recorded in India during the Eocene and was named Indobatrachus.

Family 9. Heleophrynidae Noble, 1931:

1. 8 presacral vertebrae.

2. Arciferal pectoral girdle with cartilaginous omosternum and sternum.

3. Firm stormy vertebrae.

4. T-shaped end whorls.

5. Maxillary teeth.

6. Aquatic larvae.


South Africa.


The family contains a single genus with 3 species.



Family 10. Sooglossidae Noble, 1931:

1. 8 presacral vertebrae.

2. Free coccyx.

3. A cartilaginous omosternum and a bony sternum.

4. Digits that end in small, pointed disks.


Seychelles Islands.


2 genera contain 3 species.


Somantic (1 Art); Sooglossus (2 species).

Family 11. Leptodactylidae Werner, 1896 (1838):

1. 8 presacral vertebrae with procelous centre.

2. Free from tailbone.

3. The sacrum has round diapophyses.

4. The ribs are missing.


They are found in most of South America, southern North America and the West Indies.


51 living genera contain over 900 living species.


Alguns dos gêneros são: Ceratophrys, Lepidobatrachus, Eleutherodactylus, Crossodactylus, Leptodactylus, Physalaemus, Pleurodema, etc.

Family 12. Bufonidae Grade, 1825:

1. Warty skin with parotid glands behind the eyes.

2. 5-8 presacral vertebrae.

3. Kreuzbeinfrei.

4. Absence of the transverse process on the coccyx.

5. Bony or cartilaginous sternum.

6. Omosternum absent (except Nectophrynoides, Werneria and Bufo).

7. Most species are terrestrial and have short legs.

8. Presence of proposing organ, except in Dendrophryniscus.

9. The mandibles are toothless, except for Notade, which has vomerine teeth.


Cosmopolitan in temperate and tropical regions, except Madagascar, Australia, some oceanic islands and Antarctica, although Bufo marinus has been introduced to Australia by man.


There are 25 genera, including 400 living and 20 extinct species.


Some of the genera are: Ansonia (17 species, southern India, Malay Peninsula, Philippines and Borneo). A. ornata and A. rubigina are found in Karnataka and Kerala. Owl (205 species; cosmopolitan except New Guinea, New Zealand, Australia).

16 species have been recorded in India, of which B. viridis, a migrant from Europe, is abundant in Kashmir and is also found up to 500 m altitude in the Himalayas. B. melanostictus is common throughout India. Bufoids (1 species, Meghalaya, India).

Nectophrynoides (8 species, East Africa) is the only viviparous frog in the world. Pedostibes (6 species; South India, Malay Peninsula, Sumatra and Borneo). P. kempi is found in Meghalaya and P. tuberculosus is also found in Kerala. Bufo taitanus Beiranus (.94″) from Mazambique (Africa) is the smallest frog in the world.

Family 13. Brachycephalidae Gunther, 1859:

1. 7 stormy presacral vortices.

2. Free coccyx without transverse processes.

3. Omosternum and sternum are absent.

4. Pectoral girdle partially or completely fused in the midline.

5. Aquatic tadpoles presumably absent.


Southeastern Brazil.


2 genera with five species.


Brachycephalus e Psylophryne.

Family 14. Rhinodermatidae Bonaparte, 1850:

1. Stormy presacral vortices.

2. Omostrum and external cartilaginous.

3. Absence of shields or digital dilations.

4. Free coccyx with transverse processes.

5. Poorly ossified skull.

6. Indistinct eardrum.


Chile e Argentina.


A single genus contains two species.


Rhinoderma darwini.

Family 15. Pseudidae Fitzinger, 1843:

1. 8 solid procellous presacral vertebrae.

2. Cylindrical dilated sacral diapophyses.

3. A cartilaginous sternum.

4. Maxillary teeth.

5. Water frogs with large tadpoles.


South and Central America and the West Indies.


Two genera contain 4 species.


Lysapsus (2 species); Pseudis (2 species).

Family 16. Hylidae Gray, 1825:

1. 8 stormy presacral vortices.

2. Free from tailbone.

3. Claw-shaped phalanges.

4. Dilated sacral diapophysis.

5. The phalanges are widened by the addition of a short cartilaginous element intercalated between the penultimate and terminal phalanges (ossified or absent in Cyclorana).

6. Teeth in the upper jaw.

7. Distinct toecaps present.

8. Some are aquatic, terrestrial and arboreal.

9. Larvae mainly live in water.


North and Central America, South America, West Indies, India, Australasia, Japan and North Africa.


37 living genera contain 760 species.


Some of the genera are Cyclorana (= Chiroleptes) (13 species; Australia); Lithoria (106 species; New Guinea, Solomon Islands, Australia, Tasmania, Timor, Bismarck Archipelago); Pachymesuda (1 species; Mexico); Phyllomedusa (33 species, South America); Hyla (251 species; North, Central and South America, India, northern Sahara); Castrotheca (37 species; Venezuela north of Argentina, Brazil and Panama) etc.

Hyla annectans (only the Indian hyla, found in some parts of Meghalaya and Assam).

Family 17. Centrolenidae Taylor, 1951:

1. 8 stormy presacral vortices.

2. Free coccyx without transverse processes.

3. Pectoral girdle with sternum, but without omosterum.

4. End links are T-shaped.

5. The skin on the abdomen is transparent.

6. Mainly small frogs with aquatic larvae.


Mexico to Bolivia, Argentina and Panama.


Two genera with 130 species.


Controlene and Centrolenella.

Family 18. Dendrobatidae Cope, 1865:

1. 8 stormy presacral vortices.

2. Omosternum present.

3. A pair of skin slits on the upper surface of each finger, forming sticky pads.

4. The eggs are laid on land, where the tadpoles hatch and are carried to the water by an adult.


Northwest of South America.


There are 4 genera with 117 species.


Dendrobates, Phyllobates, Atopophrynus and Colostelhus. Dendrobates are colored in warning colors and are called "South American poison dart frogs". They are extremely poisonous.

The Columbia poison dart frog (Phyllobates latinasus), whose venom is 1/100,000 grams enough to kill a human being.

Family 19. Ranidae Gray, 1825:

1. 8 stormy presacral vortices.

2. Eighth biconcave presacral vertebra and biconvex sacrum.

3. The sacrum has cylindrical shafts.

4. Free coccyx without transverse processes.

5. The pectoral girdle is generally firm sternal (the epiracoidal horns are absent, the sternum is fused to the pectoral arch, and the epiracoidal cartilages of each half of the pectoral girdle are fused). Omosternum and bone shaft in most genera.

6. The pupil is horizontal in most taxa.

7. Serrated upper jaw.

8. Commonly forked tongue.

9. Smooth and viscose skin.

10. Aquatic or semiaquatic.

11. Most have aquatic tadpoles.


Cosmopolitan except for Terra Verde, New Zealand, southern South America, West Indies and the Australian region.


The family includes 47 genera with about 700 species.


Some of the genera are Arthroleptis (11 species; sub-Saharan region); Astylosternus (11 species; West Africa); Mantella (4 species; Madagascar); Mantidactylus (53 species; Madagascar); Amolops (23 species; NE India, Nepal, S China, Greater Sunda Islands). In India, Amolops is represented by 3 species.

They are A. afghanus, Gunther, 1858 (Himachal Pradesh and Arunachal Pradesh, W. Bengal); A. formosus, Meghalaya, West Bengal, Sikkim and Punjab; A. monticola, West Bengal. Ceratobatrachus (1 species, Solomon Islands); Micrixalus (13 species; India, Sri Lanka, China, Philippines and Borneo).

In India, Micrixalus is represented by seven species, of which M. borealis Annandale, 1912 occur in Arunachal Pradesh and the rest in Kerala and Tamil Nadu. Nannobatrachus (3 species; South India); Nannobatrachus beddomii Boulenger, 1882 (Kerala and Tamil Nadu) is 20 mm long and is the smallest frog from the Indian subcontinent.

Nannophrys (3 species; Sri Lanka); Nannorana (1 species, China); Nyctibatrachus (4 species, India); Occidozyga (9 species; West Bengal to southern China, Greater and Lesser Sunda Islands); O. lima Kuhl and Van Hasselt, 1822, the only Indian species found in W. Bengal; Platymantis (38 species; Philippines, New Guinea, Palau, Fiji and Solomon Islands). Toad (258 species; worldwide except southern South America and Australia).

55 species have been recorded in India. among Indian species. R. limnocharis (rice frog), R. cyanophlyctis (captain's frog) are common throughout India. R. tigerina is known as the Indian bullfrog. R. verrucosa occurs in the Malabar Hills up to 230 m in the Nilgiris and 1300 m above in Kerala.

Common frogs in different countries are: R. japonica (Japan, Korea and China); R. cancrivora (Thailand and northern parts of the Malay Peninsula); Italian saltina frog (R. latastei); Spanish frog (R. iberica); brook toad (R. graeca); American bullfrog (R. catesbiana); American wood frog (R. sylvatica).

The hairy toad (Trichobatrachus robustus), found in East Africa, is famous for the hair-like bumps on the sides of the abdomen and thighs during the male's breeding season. Cigantorana goliath is famous for its gigantic size and is found in the tropical region of sub-Saharan Africa. The frog is about 60 cm long and is the largest frog in the world.

Family 20. Hyperoliidae Laurent, 1943:

1. 8 stormy presacral vortices.

2. The eighth presacral vertebra is biconcave and the sacrum is biconvex.

3. Free coccyx without transverse processes.

4. The chest belt is tight; a cartilaginous or bony omosternum and sternum.

5. Oberkieferzahn.

6. The vertically elliptical pupil in most genera.

7. Mainly frogs with waterworms.


Sub-Saharan region in Africa.


There are 14 genera with 230 species.


Some of the genera are Afrixalus (23 species); Callixallus (1 species).

Hyperolius (109 species); Tachycnemis (1 species, Seychelles Islands).

Family 21. Rhacophoridae Hoffman, 1932:

1. 8 pre-sacral stormy vortices.

2. The eighth presacral vertebra is biconcave and the sacrum is biconvex.

3. The shoulder girdle is tight. The omosterum and sternum are bony.

4. The phalanges are enlarged by the addition of short cartilaginous elements (bony in some taxa) between the penultimate and terminal phalanges.

5. Severely webbed hands and feet.

6. The fingers and toes have disc-shaped sticky pads.

7. Most tree dwellers, except Aglyptodactylus, which is terrestrial.


Old World Tropics.


There are 10 genera with about 315 species.


Some of the genera are — Boophis (28 species, Madagascar); Chiromantis (3 species, tropical Africa); Philautus (63 species; India, Sri Lanka to China, Philippines and Greater Sunda Islands). In India, Philautus is represented with 28 species, numerically comparatively larger than the genus Rhacophorus.

All species of the genus Philautus are characterized by a horizontal pupil, and the fingers and toes are provided with sticky pads and the absence of vomeric teeth. They are restricted to southern India and the eastern Himalayas.

Polypedals (11 species, tropical Asia). Polypedates leucomystax Gravenhorst 1829 (W. Bengal, Assam and Sikkim), P. maculatus (throughout India) and P. pseudocruciger Das and Ravichandran, 1998 are recorded from India Rhacophorus (56 species; India, China, Japan and Greater Probe). Rhacophorus is represented by 11 species in India.

Rhacophorus malabaricus Jerdon 1870 (Kerala and Karnataka) is found more or less throughout India and is famous for using its webbed feet to parachute from the top of one tree to the base of another. Rhacophorus is famous for building foam nests, sometimes placed on plants over water, and the eggs hatch into tadpoles.


Liem, S. (1970) reported 56 species under the genus Rhacophorus Kuhn and Van Hasselt, 1822 from India, China to Japan and the Great Sunda Islands, and Polypedates Ichudi, 1838 (11 species) from Japan and E. China throughout. the tropics. Asia to Java, the Bornes and the Philippines. Boulenger (1890), Daniel (1963, '75), Duellman and Trueb (1986), Pillai and Murthy (1986) also reported that the genus Rhacophorus occurs only in the Indian region.

But Frost (1985), Inger and Dutta (1986) mentioned Polypedates leucomystax and Polypedates maculatus (1834) in the Indian region in their list of amphibians. The two species used to belong to the genus Rhacophorus.

Family 22. Microhylidae Gunther, 1859:

1. 8 pre-sacral procoel vertebrae.

2. The ribs are missing.

3. Coccyx is free.

4. The shoulder girdle is tight.

5. Omosternum is absent in most genera.

6. There is a cartilaginous sternum.

7. Palates are reduced or absent in most genera.

8. Edentulous upper mandible in most genera, but present Calluela, Dyscophus, Cophyla, Mantipus, Plethodontohyla, Platypelis, Paracophylla, Stumpffia.

9. The fingers of some species are expanded and the phalanges are T-shaped.

10. The pupil is horizontal or round (vertically elliptical in Calluela and Dyscophus).

11. The skin is smooth or warty.

12. The body is small, stout and with a small head for ball, ground or tree frogs with short legs.

13. Presence of two to three palatine folds.


Cosmopolitan in temperate and tropical regions, except the Palearctic and most of Australia.


61 genera and about 315 species.


Some of the genera are Pseudohemisus (6 species, Madagascar); Callet (5 species, Southeast Asia and Malay Archipelago); Dyscophus (3 species, Madagascar); Mantipus (7 species, Madagascar); Pherohapsis (1 species, Papua and New Guinea); Xenobatrachus (9 species, New Guinea); Breviceps (12 species, South Africa); Callulina (1 species, Tanzania); Melanobatrachus (1 species, South India); Kaloula (9 species, India, Sri Lanka, Korea, northern China and Philippines); Microhyta (21 species, India, Sri Lanka, Bangladesh, Southeast Asia); Ramnella (8 species, India and Sri Lanka); Uperodon (2 species, India and Sri Lanka).

Melanobatrachus indicus Beddome, 1878 (Kerala) is recognized by the absence of palatine ridges and is represented by a single species. Microhyla has 5 species in India and is found across the country including Andaman.

It can be recognized by the circular pupil, the entire oval tongue, the palatine ridges and with or without terminal extensions on the fingers. Kaloula is represented by a single species. K. pulchra taprobanica is the most beautiful frog of all living Indian anthers.

Ramanella is represented by 6 species in India and can be recognized by enlarged fingers and toes, color patterns and the presence or absence of webbed feet. Another genus Uperodon is represented by U. globulosus and U. systoma and is known as "balloon frog".

They can be recognized by their narrow mouth, round body and a crest that ends behind or between the nostrils. They are found in W. Bengal, MP, Orissa, Gujarat, Maharashtra and South India.

life connectionRequests from:

From the analysis of collected fossils and the structural features of living representatives, it is clear that urodels evolved independently from Porolepis fish, have an internal nostril, and this group acts as an intermediary between fish and amphibians.

Due to the subterranean way of life, fossils of Apodans are not enough, although some fossils from Jurassic beds have been collected recently and are considered the most primitive group.

Its fossal habit influenced its morphological characteristics to some extent, and the retention of scales on the skin also indicates primitivism. Anurans are the most advanced group of amphibians and have adapted to different environments, increasing their adaptability value.


The fossil record does not conclusively confirm that early amphibians evolved from Devonian Rhipidistians, as there is a gap in the fossil record sequence between Middle Devonian Rhipidistians and Late Devonian amphibians.

However, a large proportion of herpetologists endorse the Devonian ripidists as the ancestors of amphibians. They believe that the first amphibians evolved from groups of Crossopterygia, mainly Osteolepis and Eusthenopteron.

Today, the Panderichthyidae, a newly defined lineage of Late Devonian crossopterygians, are considered the ancestors of the first amphibians.

The Ripidistios managed to reach land from the aquatic environment.

When they reached land, these fish became the first amphibians: Ichthyostega, belongs to the subclass Labyrinthodontia. From Ichthyostega two main lineages can be assumed, the orders Anthracosauria and Temnospondyli. Anthracosaurs gave rise to reptiles at the end of the Carboniferous period, completing the first part of amphibian history.

The second lineage includes the lepospondyl amphibians (subclass Lepospondyli), which appeared in the middle Carboniferous and disappeared at the end of the Permian. The third part of the amphibian history includes the modern amphibians that fall into the subclass Lissamphibia and represent the diverse fossils of the Jurassic bed.

The origin of lepospondyls and lyssamphibians remains an unanswered question due to fossils yet to be discovered.

Possible views on the origin of amphibians:

1. Polyphyletic view [Carroll and Currie,1975; Jarvik, 1980-81]:

They hypothesized that the three living orders, for example Urodela, Apoda and Anura, evolved separately. Jarvik (1980) also noted that amphibians evolved independently of more than one group of Ripidistian fish.


This opinion is not accepted by everyone.

2. Diphyletic vision [Romer, 1949, 1962;Romer e Watson, 1962]:

They proposed that both salamanders and caecilians share a common ancestor and that frogs evolved separately. Emphasizing the spinal similarities in the different groups, anurans are thought to have evolved from labyrinthodonts and urodelians, and apodena from lepospondyls.

But Romer (1931) assumed that salamanders and frogs share a common ancestor and that caecilians evolved separately.

3. Monophilic view [Noble, 1931; screws,1979; McFarland et al., 1985; Duellman e Trueb, 1986]:

They assumed that all living amphibians evolved from the first amphibians, the Ichthyostega, and that this group also descended from osteolepid fish (Osteolepis sp.).

amphibian discoveries:

New species of the amphibian class are discovered more frequently than many other vertebrate taxa. The number of species is expected to reach 5,000 by the year 2000. In 1985, there were 4,003. The rapid increase in numbers can be explained by the use of molecular techniques to separate morphologically cryptic species.

Global assessment of amphibians:

About a third (32.5%) of the global amphibian population of 1,856 species has been listed as Critically Endangered (CE), Endangered (En) and Vulnerable (Vu) in the Red Data Book.

At least 34 amphibian species will become extinct, 134 amphibian species are likely to become extinct, 9 amphibian species have become extinct since 1980, and at least 113 other species may have become extinct during that time.

Salamanders and newts show a significantly higher level of threat, including about 234 species (46%) among all urodels. Frogs and toads include 1,635 species (32.6%) as threatened, and little data is known for the rest of cacilians.

Research on Indian Amphibians:

Since the 19th century, herpetologists have primarily researched the taxonomy and distribution of Indian amphibians. Some of the notable works by Gunther (1861), Cope (1865), Jerdon (1870), Anderson (1871), Stoliczka (1872), Boulenger (1883, 1890, 1892 and 1920) and Sclater (1892) etc.

Among the researchers mentioned above, Boulenger (1890) published a comprehensive work on the Indian amphibians in the "Fauna of British India, including Ceylon and Burma". In 1920, Boulenger published a monograph on the genus Rana in Southeast Asia. Ferguson (1904) published in Travancore Batrachians.

Annandale (1908), the first Director (Superintendent) of the Zoological Service of India, published the reproductive habits of Tylototriton verrucosus. In 1912 he reported on the amphibian fauna of the Abor Expedition (Abor Hills).

C. R. N. Rao (1915-37) published on various South Indian frogs and also described the various larval forms found in various groups of amphibians. Hora (1921-1922) studied the larval forms of torrent amphibians.

Kampan (1923) reported on Indian amphibians in his treatise "Amphibia of the Indo-Australian Archipelago". Parker (1934) published on microhybrid frogs.

Bhaduri (1944-45, 1955) reported the reproductive behavior of Rhacophorus and also reported the behavior of the narrow-mouthed frog Uperodon giobulosus. Acharjee and Kripalini (1951) studied the amphibian fauna of the western Himalayas. E. H. Taylor of the University of Kansas (1961-1962) discussed the Cecilian Indians. Murthy (1964) studied the fauna of Rajasthan.

In 1973 he published the distribution of microhylid frogs (Ramanella variegata). Pillai (1976-1981) studied the amphibian fauna of southern India using Silent Valley.

Daniel (1962-1999) published a series of papers on the distribution, taxonomy and ecology of amphibians in the Darjeeling district of West Bengal and, in particular, amphibians of western India. In 1997 he reported on frogs and toads from the Western Ghats.

Dubois (1978-1997) studied the amphibians of the central and western Himalayas. He also reviewed the amphibian fauna of India, particularly the family Ranidae. Chanda (1981-1994) studied the amphibian fauna of northeast India and also Sikkim. Furthermore, in 1994 he published a detailed description of 54 known species from the northeast region. Mahanti-Hejmadi (1985) published the amphibian fauna of Orissa.

Sarkar and Sanyal (1985) published the report on the amphibians of Namdapha National Park, Arunachal Pradesh. Dutta (1985) published some observations on the habits of burrowing toads found in Orissa. He also published A Checklist and Bibliography of the Amphibians of India and Sri Lanka in 1997.

Ingerand Dutta (1986) gave an overview of the amphibian fauna of India. About the Indian salamander (Tylototriton verrucosus), several authors such as Singh (1987), Roy (2002) reported the new occurrence and habits of this endangered species and Sekar (1991, 1992) described the amphibian fauna of Goa.

Mallick and Mallick (-1982) reported foam nests in polypedates. Mallick, Mallick and Das (1980) published the spawning behavior of 4 outcrops in West Bengal. Krishnamurthy (1999) studied the amphibian fauna of the Western Ghats.

Ravichandran (1996) surveyed the amphibian fauna at the Kalakad Wildlife Sanctuary in Tamil Nadu and also reported in 2002, 2004 on the diversity of appendectomy in India with reference to Western Ghats, Eastern Ghats and Northeast India. Padhye and Ghate (2002) studied the amphibian fauna in the state of Maharashtra. Meren, Bordoloi and Ohler (2003) reported the amphibian fauna of Nagaland with new records from India.

Banerjee and Chakrabarty (2003) studied chromosomal sex determination in anuran amphibians. Biju (2002) conducted a field study in the Western Ghats. He recorded 104 species of 206 frog species reported from India. Biju and Bossuyt (2003) created a new family of frogs from India that reveals an ancient biogeographical connection with the Seychelles.

The molecular phylogeny of Indian amphibians is at an early stage, but phylogenetic relationships at the molecular level are gradually improving.

indian species:

The amphibian fauna consists of 3960 living species found all over the world except Antarctica and some oceanic islands. In India, Boulenger first published an overview of the amphibian fauna in the book Fauna of British India - Reptilia and Batrachia in 1890, which contained only 77 species. The literature of the last hundred years has added many names to

The herpetologist's dilemma:

Herpetologists or amphibian biologists face a dilemma regarding nomenclature changes in different groups. Taxonomists or field biologists cannot deal with changes in the scientific names of different groups. If we look at the case of the Indian bullfrog Rana tigerina, the condition can be understood.

First, the specific name was misspelled and corrected from tigrina to tigerina. Then the genus name was changed from Rana to Occidozyga, which studies Indian amphibians.

Pillai and Murthy (1986) reported 142 species in the three orders of which Gymnophiona contains 15 species, Urodeles-1 and Anurans-126. Inger and Dutta (1986) also published a list mentioning 186 species.

The single species of urodels Tylototriton verrucosus Anderson, 1871 (Darjeeling district, West Bengal, Sikkim and Arunachal Pradesh) and 4 genera of Cecilians: (i) Ichthyophis (7 species) (ii) Uraeotyphlus (4 species) (iii) Gegenophis ( 3 species) and (iv) Indotyphlus (1 species)” were recorded.

The species of four genera of Apodans are:

(i) Ichthyophis bombayensis Taylor, 1960 (Maharashtra);

(ii) I. subterrestris Taylor, 1960 (Maharashtra und Kerala);

(iii) I. beddomei Peters, 1879 (Kerala, Karnataka and Tamil Nadu);

(iv) I. malabarensis Taylor, 1960 (Kerala);

(v) I. penisularis Taylor, 1960 (Kerala and Tamil Nadu);

(vi) I. sikkimensis Taylor, 1960 (West Bengal e Sikkim);

(vii) I. tricolor Annandale, 1909 (Kerala);

(viii) Uraeotyphlus malabaricus (Beddome, 1870) (Kerala);


(ix) U. menoni Annandale, 1913 (Kerala);

x) U. narayani Seshachar, 1939 (Kerala);

(xi) U. oxyunvs (Dumeril and Bibron, 1841) (Kerala);

(xii) Gegenophis carnosus (Beddome, 1870) (Kerala);

(xiii) G. fulleri (Alcock, 1904) (Assam);

(xiv) G. ramaswamii Taylor, 1964 (Kerala);

(xv) Indotyphlus batedoresbyi Taylor, 1960 (Khandala, Maharashtra).

Anurans are represented by the following genera: Amolops, Nannobatrachus, Nyctibatrachus, Micrixalus, Frog, Tomopterna, Rhacophorus, Chirixalus, Polypedates, Philautus, Theloderma, Uperodon, Kaloula, Ramnella, Microhyla, Melanobatrachus, Bufo, Buphonoides, Ansonia, Pedostibes, Megophrys. . . . B. Leptobranchium Scutiger and Hyla.

The herpetologist's dilemma:

Herpetologists or amphibian biologists face a dilemma regarding nomenclature changes in different groups. Taxonomists or field biologists cannot deal with changes in the scientific names of different groups. If we look at the case of the Indian bullfrog Rana tigerina, the condition can be understood. It was first changed to Euphlyctis, and today the genus name is Hoplobatrachus.

Rare and critically endangered Indian species:

The Indian fire salamander (Tylototriton verrucosus), the Malabar tree frog (Pedostibes tuberculosus), the Garo Hills tree frog (Pedostibes kempi) have all been classified as Rare or Endangered. The Hylidae family is represented by a single species, Hyla annectans Jerdon, 1870, which inhabits parts of Assam and Meghalaya.

The Indian viviparous toad (Nectophryne tuberculosa = Pedostibes tuberculosus), a very rare amphibian, is found in the vast expanses of the Malabar rainforest.

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What are the 3 categories of amphibians and how are they different? ›

They are classified into three orders: frogs and toads, salamanders and newts, and caecilians. Frogs and toads are adapted for jumping. Salamanders and newts may walk or swim. Caecilians live in the water or soil and are the only amphibians without legs.

What are the 3 classes of amphibians common names )? ›

What are three types of amphibians? Amphibians are found in class amphibia, which is broken into three orders. These orders are Anura (frogs and toads), Caudata (salamanders and newts), and Gymnophiona (caecilians).

What are 3 characteristics that all amphibians share? ›

There are several characteristics all amphibians share:
  • Have a back bone and are considered vertebrates.
  • Are cold-blooded, which means they are unable to regulate their own body temperature.
  • Spend part of their lives in water and on land.
Nov 3, 2021

What are the three stages of amphibians? ›

It includes three stages: Egg, larva, and adult

Frogs are not the only animals to undergo metamorphosis; most other amphibians also undergo remarkable changes throughout their life cycles, as do many species of invertebrates.

What are the types of amphibians? ›


What are amphibians give 3 examples? ›

Answer: Frog and Toad.
  • The class of Amphibian can live in both land and water. They lay their eggs in water.
  • The body of amphibians are covered with slimy and slippery skin.
  • These animals breathe through their skin and lungs.
Jul 3, 2022

What are the three major groups of amphibians quizlet? ›

Terms in this set (9)
  • Salamanders.
  • Frogs and toads (anurans)
  • Caecilians.

How many types of amphibians are there? ›


What are the 3 orders of amphibians and an example of each? ›

There are three orders of amphibians: Anura (frogs), Caudata (salamanders), and Gymnophiona (caecilians).

What are 3 facts about amphibians? ›

Amphibians can live both in land as well as in water. Their name comes from a Greek word 'amphibios' which means 'both lives'. Frogs, salamanders and toads are all amphibians. The world's largest frog is the Goliath Frog, which lives in western Africa!

Do amphibians have 3 body parts? ›

Amphibians are the first true tetrapods, or vertebrates with four limbs. Amphibians breathe with gills as larvae and with lungs as adults. They have a three-chambered heart and relatively complex nervous system.

What are the 4 types of amphibians? ›

Amphibians are a class of cold-blooded vertebrates made up of frogs, toads, salamanders, newts, and caecilians (wormlike animals with poorly developed eyes).

What are Class 4 amphibian animals? ›

An amphibian is a cold-blooded vertebrate animal that is born in water and breathes with gills. As the larva grows into its adult form, the animal's lungs develop the ability to breathe air, and the animal can live on land. Frogs, toads, and salamanders are all amphibians.

What are the basic characteristics of amphibians? ›

  • Amphibians are vertebrates.
  • Their skin is smooth and slimy.
  • Amphibians breath through their skin, as well as their lungs in some cases.
  • Amphibians are cold-blooded.
  • They have a complex life cycle (larval and adult stages).
  • Many species of amphibians vocalize.

What are three main characteristics of amphibians quizlet? ›

Amphibians; bony skeleton; moist, glandular skin; two pairs of limbs; three-chambered heart; (ex. toad, frog).

What are the 3 stages of the frog life cycle? ›

In summary, these are: Stage 1: Egg. Stage 2: Tadpole. Stage 3: Froglet (young frog)

What are the three orders of small amphibians? ›

Biologists divide class Amphibia into three major groups: frogs and toads (order Anura), salamanders (order Caudata), and the limbless caecilians (order Gymnophiona), which are found only in the tropics.

What is the most common type of amphibians? ›

The most common amphibian critter is a frog but there are many others.

What are the 5 groups of amphibians? ›

Today amphibians are represented by frogs and toads (order Anura), newts and salamanders (order Caudata), and caecilians (order Gymnophiona).

What are the 7 main characteristics of amphibians? ›

What are the 7 main characteristics of amphibians? Amphibians have a backbone, are cold-blooded, need a moist place to live, can breathe air through their skin, externally fertilize their eggs, eat meat, and grow legs when they mature.

Why is frog an amphibian class 3? ›

The word "amphibian" is derived from the Greek term "amphibios" (amphi = dual or both, bios = life). Frog is thus, called an amphibian because it typically lives on land but requires water for fertilisation and development.

What are the 3 regions of a frog? ›

As in other higher vertebrates, the frog body may be divided into a head, a short neck, and a trunk. The flat head contains the brain, mouth, eyes, ears, and nose. A short, almost rigid neck permits only limited head movement. The stubby trunk forms walls for a single body cavity called the coelom.

What are the three groups of reptiles? ›

Reptiles generally are divided into four groups: Squamates, turtles, crocodilians and Rhynchocephalians. Squamates include lizards, snakes and worm lizards, also called Amphisbaenians.

What are 3 traits that helped amphibians adapt to living on land? ›

In order to be able to live on land, amphibians replaced gills with lungs as the respiratory organ. Other adaptations include skin that prevents water loss, eyelids that allow them to adapt to vision outside water, and limbs as the locomotory organ.

What are three reasons amphibians are important? ›

Amphibians contribute to regulating services by reducing mosquito recruitment from ephemeral wetlands, potentially controlling other pest species, and indirectly through predation of insect pollinators.

Why do amphibians have 3 chambers? ›

Amphibians and reptiles (except for crocodiles) contain a three-chambered heart with only one ventricle. This is because these animals have a slower metabolism rate and hence, they require a lower amount of oxygen per liter of blood to be delivered to the body.

Do amphibians have three chambers? ›

Amphibians have 3 heart chambers: 2 atria and 1 ventricle.

How is the body of amphibians divided? ›

(i) The body is divisible into head and trunk. The tail is present in some amphibians.

What are amphibians Grade 5? ›

Amphibians are cold-blooded vertebrates (vertebrates have backbones) that don't have scales. They live part of their lives in water and part on land.

What are the classification of amphibians for kids? ›

There are three basic groups of amphibians. The first group consists of frogs and toads. The second group consists of salamanders, including newts and mud puppies. The third group is made up of wormlike creatures called caecilians.

What are the three groups of amphibians quizlet? ›

Terms in this set (9)
  • Salamanders.
  • Frogs and toads (anurans)
  • Caecilians.

What makes an amphibian different? ›

All amphibians spend part of their lives in water and part on land, which is how they earned their name—“amphibian” comes from a Greek word meaning “double life.” These animals are born with gills, and while some outgrow them as they transform into adults, others retain them for their entire lives.

What are 3 adaptations frogs have that make them amphibians? ›

Skin that prevents loss of water. Eyelids that allow them to adapt to vision outside of the water. An eardrum developed to separate the external ear from the middle ear.

What are the 3 groups of animals? ›

Three different types of animals exist: herbivores, omnivores, and carnivores. Herbivores are animals that eat only plants. Carnivores are animals that eat only meat. Omnivores are animals that eat both plants and meat.

How many groups of amphibians are there? ›

Amphibians can be divided into three groups: Urodela (salamanders), Anura (frogs), and Apoda (caecilians).

What are 5 characteristics of amphibians? ›

Amphibians have a backbone, are cold-blooded, need a moist place to live, can breathe air through their skin, externally fertilize their eggs, eat meat, and grow legs when they mature.

What are the main characteristics of amphibians? ›

Modern amphibians are united by several unique traits. They typically have a moist skin and rely heavily on cutaneous (skin-surface) respiration. They possess a double-channeled hearing system, green rods in their retinas to discriminate hues, and pedicellate (two-part) teeth.

What are 5 adaptations of amphibians? ›

There are several features of amphibians that make them dependent on water to survive. These include a permeable skin; a body subject to dehydration, external fertilization, eggs without shells and a larval stage with branchial respiration.


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