The platypus, found only in Australia is one of the five mammal species of that lay eggs instead of giving birth to live young. ... The reason that odd, egg-laying mammals still exist today may be because their ancestors took to the water, scientists now suggest.

What are the two mammals that lay eggs?

Mammals. As for us mammals, only two types lay eggs: the duck-billed platypus and the echidna.

What are the 5 egg-laying mammals?

Only five species of animals share this extraordinary egg-laying trait: the duck-billed platypus, western long-beaked echidna, eastern long-beaked echidna, short-beaked echidna, and Sir David's long-beaked echidna. All of these monotremes are only found in either Australia or New Guinea.