The ear consists of three parts: inner, middle, outer ear Some vertebrates lack middle and outer ear (Chondrichthyes, Osteichthyes). Middle ear appeared in amphibians. Reptiles, birds, mammals have ...

amphibians and fish. Mammals are warm-blooded animals with hair or fur and can produce milk to feed their young. They have three ear bones, which allow for better hearing. They also have a special ...