What are the features of similarity in the structure of amphibians and fish and explain what this proves.

Amphibians have significantly fewer bones in comparison with fish: many bones grow together, in some places cartilage is preserved. The skeleton is lighter than that of fish, which is important for terrestrial existence. The broad, flat skull and upper jaws form a single entity. The lower jaw is very mobile. The skull is movably attached to the spine.
There are more divisions in the spine of amphibians than in fish. The skeleton of free limbs of amphibians, in contrast to fish, is complex.
Similarities: are of the same type.