According to a new study, the first louse to take up residence on a mammalian host likely started out as a parasite of birds. That host-jumping event tens of millions of years ago began the long ...

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 ...

The definition of a mammal is a warm-blooded vertebrate animal distinguished by the possession of hair or fur, the secretion of milk by females for nourishing their young, and the birth of live ...

An international team has reconstructed the genome organization of the earliest common ancestor of all mammals. The reconstructed ancestral genome could help in understanding the evolution of mammals ...

More than 220 million years ago, as early dinosaurs were just getting their legs under them, the first mammals evolved from a group of tiny, weasel-like reptiles called cynodonts. New research hints ...