Placental mammals all bear live young that are nourished via an organ in-utero. The study revealed that a Cretaceous origin for placental mammals, the diverse group that includes humans, dogs, and ...

Tyrannosaurus rex may never have had the chance to terrorize the grandfathers of rodents, rabbits or primates. A new family tree using both anatomical and genetic data indicates that the lineages of ...

A tiny, furry-tailed creature is the most complete picture yet as to what the ancestor of mice, elephants, lions, tigers, bears, whales, bats and humans once looked like, researchers say. These new ...

It was about six inches long from head to tail, a furry, shrew-like tree-climber that ate insects and maybe worms, and probably hid out during the day to stay away from marauding dinosaurs. This small ...

A Cretaceous origin for placental mammals, the group that includes humans, dogs and bats, has been revealed by in-depth analysis of the fossil record, showing they co-existed with dinosaurs for a ...

Around 100 million years ago, a remarkable evolutionary shift allowed placental mammals to diversify and conquer many cold regions of our planet. New research from Stockholm University shows that the ...

In the wake of the dinosaurs’ demise, a bizarre beast that some researchers have nicknamed “ManBearPig” lived life in the fast lane. This sheep-sized mammal — which sported five-fingered hands, a ...

The first mammals first lived some 160 million years ago, in a world ruled by reptiles. And now scientists suggest that hiding in the dark from these terrifying beasts may have left an imprint in ...

They are the most successful mammals that you probably haven’t heard of. Multituberculates were squirrel-like mammals that first evolved in the Jurassic, about 170 million years ago, and survived ...