Question

Discuss why frogs and toads are called amphibious animals and are placed in class amphibians.

Answer 1

A frog is any member of the Anura order, which consists of a varied and mostly carnivorous group of short-bodied, tailless amphibians. The earliest fossil "proto-frog" was discovered in Madagascar during the early Triassic period, although molecular clock dating shows its beginnings date back to the Permian period, 265 million years ago.

Complete answer:
Toad is a popular term for frogs with dry, leathery skin, short legs, and big bumps covering the parotoid glands, especially those belonging to the Bufonidae family. Amphibians are tetrapod animals that are ectothermic and belong to the class Amphibia. Lissamphibia is the name given to all live amphibians. They live in a broad range of environments, with the majority of species inhabiting terrestrial, fossorial, arboreal, or freshwater aquatic settings. As a result, most amphibians begin their lives as larvae in water, although certain species have evolved behavioral adaptations to avoid this.
The larvae with gills metamorphose into an adult air-breathing species with lungs in most cases. Amphibians utilize their skin as a secondary respiratory surface, and some tiny terrestrial salamanders and frogs do not have lungs and rely only on their skin for respiration. They resemble lizards on the surface, but reptiles, like mammals and birds, are amniotes, which means they don't need water to reproduce. Amphibians are typically ecological indicators due to their complicated reproductive demands and porous skins; amphibian populations have been declining dramatically for several species throughout the world in recent decades.
Anura (frogs), Urodela (salamanders), and Apoda (amphibians) are the three extant amphibian orders (the caecilians). There are roughly 8,000 amphibian species known, with frogs accounting for nearly 90% of them. A frog from New Guinea (Paedophryne amauensis) is the world's tiniest amphibian (and vertebrate), measuring just 7.7 mm in length (0.30 in).
Thus, An amphibian is a creature that begins life as a water-breathing species but eventually evolves into an air-breathing creature. Frogs begin their life as eggs in the water, then as tadpoles, and finally as fully formed adults on land. There are about 4,000 distinct species of amphibians on the planet. The amphibian family also includes newts, salamanders, and caecilians (blind worms).

Note:
The first amphibians developed from sarcopterygian fish with lungs and bony-limbed fins, which helped them adapt to dry land during the Devonian period. During the Carboniferous and Permian eras, they evolved and were dominant, but were eventually replaced by reptiles and other animals. Amphibians have shrunk in size and variety through time, leaving just the Lissamphibia subclass.