Typically, mammals give birth to live young. However, three unusual species defy this norm. Scientists are intrigued by the ...

A new study suggests the platypus and echidna — the only egg-laying mammals — had a water-dwelling ancestor. The finding ...

Analysis of the fossil suggests that the only two egg-laying mammals, platypuses and land-based echidnas, both descended from ...

Neither animal has teeth, and though they both produce milk, they secrete it through ... probably shared a lot more biology with a monotreme than with a horse, a dog, a cat or ourselves.” ...

The platypus and echidna, often regarded as some of the most peculiar animals on Earth, may be hiding a far more complex ...