Why Do Egg Laying Mammals Still Exist?
The reason that odd, egg-laying mammals still exist today may be because their ancestors took to the water, scientists now suggest.
The egg-laying mammals — the monotremes, including the platypus and spiny anteaters — are eccentric relatives to the rest of mammals, which bear live young. In addition to laying eggs, other quirks make them seem more like reptiles than our kin. They have a reptilian gait with legs on the sides rather than underneath the body, for instance, and a single duct for urine, feces and sex instead of multiple openings.
These oddities are often considered primitive “living fossils” that shed light on what our distant ancestors might have looked like…
(read more: Live Science)