Learn more about Morganucodon and Brasilodon, the two species that may have given life to the mammals we know today.

Earth’s earliest mammals spent their lives at a more leisurely pace than their modern counterparts, but they lived a lot longer, analysis of some 200-million-year-old teeth has shown.

Fossils of the first winged mammals dating back 160 million years to the age of the dinosaurs have been discovered. The remains, from the Jurassic period, suggest a new way of life - gliding - for ...

Until now, science had viewed the first mammals solely as tiny shrewlike creatures that lived in the shadow of the dinosaurs. By day, these early mammals hid in caves; ...

The world's oldest known mammal has been identified using dental records – predating what scientists previously thought was the first mammal to walk the Earth by millions of years – according ...

The first mammal-like animals emerged alongside dinosaurs in the Mesozoic Era, aptly known as “the Age of Reptiles.” Based on fossilized bone and skeletal impressions, ...

You can say this about mammals: We've had a good run. Over the 250 million years since the first mammals diverged from reptiles and birds, we hairy, warm-blooded vertebrates have come to dominate ...

For some mammals, the evolutionary path to gigantism after the dinosaurs’ demise wasn’t always a straight road. Species of extinct, hefty, rhinoceros-like creatures called brontotheres evolved ...

Endothermy, or warm-bloodedness, is the ability of mammals and birds to produce their own body heat and control their body temperature.