Dinosaurs so thoroughly dominated the ancient world that they suppressed the evolutionary possibilities open for mammals. This notion has been around for decades now, and it seems to be backed up by ...

Despite a common narrative that male mammals tend to dwarf female ones, fewer than half of mammalian species display that pattern, a new study suggests. By Emily Anthes Female elephant seals are not ...

A new study suggests that endothermy appeared in mammalian ancestors about 233 million years ago, well before the origin of mammals, which occurred about 200 million years ago. Endothermy, or ...