New Scientist is carrying this report detailing a bizarre animal which might represent an evolutionary step toward mamals:

Nursing mothers of Boulengerula taitanus – part of a group of tropical, legless terrestrial amphibians called the caecilians – transform the top layer of their skin from its usual flat, dead cells to a thicker layer of large cells rich in protein and fats in order to nurture their young. The nutrient content of this skin layer is similar to that of milk.

The thinking is this could represent an intermediate step toward both live birth and nursing. Kinda creepy, if you ask me.