Question

Echidna is an oviparous animal, even then it is considered a mammal because they are

• A. Warm blooded animal
• B. Have hair on skin
• C. Produce milk through mammary glands to feed their young
• D. All of the above

Answer 1

The correct option is D All of the above

Mammals are viviparous organisms while Echidna is oviparous, even then it is placed in class Mammalia as it possesses the basic mammalian characters like the presence of mammary glands, a diaphragm between thorax and abdomen, four-chambered heart, non-nucleated RBCs, etc. However, due to its oviparous nature, Echidna has been assigned an infra-class Prototheria. Thus, the correct answer is option D.