Marsupials used to be considered an evolutionary stepping stone between egg-laying mammals called monotremes, such as platypuses, and placental mammals, such as humans, according to the new study.

Australia and South America were isolated from other continents during much of the Tertiary, and marsupial mammals thrived and diversified there, while placental mammals took over similar roles on ...

Marsupials have split from placental mammals about 120–180 million years ago. If marsupials had functional brown fat and its thermogenic protein, it would suggest that the organ existed before ...