A controversial idea suggests the ancestors of echidnas were more like the platypus. For the first time, fossil evidence ...

A small bone found 30 years ago at Dinosaur Cove could revolutionize our understanding of echidnas and platypuses' evolution.

An analysis of a 100-million-year-old fossil has found that the creature it belonged to, similar to a monotreme like the echidna and platypus, was water-dwelling. The study supports the theory ...

As the world's only surviving egg-laying mammals, Australasia's platypus and four echidna species are among the most extraordinary animals on Earth. They are also very different from each other.

Australia's burrowing echidna evolved from a water-dwelling ancestor in an "extremely rare" biological event, scientists said Tuesday in a new study of the peculiar egg-laying mammals. With ...