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 ...

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 ...

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 ...

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 ...

Mammals, including humans, stand out with their distinctively upright posture, a key trait that fueled their spectacular evolutionary success. Yet, the earliest known ancestors of modern mammals more ...