Question

Ichthyopis belongs to the class
(a) Amphibia
(b) Reptilia
(c) Aves
(d) None of the above

Answer 1

Hint: The first vertebrates to walk out of the water that can lead dual-mode of life which depend on aquatic habitat for reproduction and development due to the lack of eggshell. The sternum is seen for the first time in these organisms.

Complete answer:
The first vertebrates to come out of the water and walk on the land are amphibians. They are tetrapods that have the ability to live on both land and in water. They flourished during the carboniferous period. They are not completely terrestrial because their eggs dry out quickly when laid on land due to the absence of shells, so, for reproduction and development they choose aquatic habitat. Some of the organisms that belong to amphibians are ichthyophis(limbless amphibian), Bufo(toad), Rana(frog), Hyla(tree frog), Rhacophorus(flying frog).

Additional Information: - Amphibians are the first tetrapods to lead a dual-mode of life i.e, they can survive both on land or in water.
- Soft and scale-less, moist, and glandular skin is present
- Two pairs of equal or unequal pentadactyl lime are present on the body.
- As in mammals, amphibians also have dicondylic skull
- Procoelous, opisthocoelous, and amphicoelous vertebrae are seen. The appearance of the sternum was seen for the first time in amphibians.
- Acrodont, homodont, and polyphyodont dentition is seen in the mouth
- Exchange of respiratory gases is via the skin, lungs, and buccopharyngeal region.

So, the correct answer is ‘amphibia’

Note: Skin in all amphibians is soft and scale-less, moist, and glandular but in members of Apoda soft and scaleless skin is not present.
Heat is three-chambered with sinus venosus and conus arteriosus.
ichthyophis(limbless amphibian) belongs to members of Apoda.