News Paleontology

Fossils push back origins of modern mammals

Common ancestor evolved over 200 million years ago

drawing mouse-sized mammal Xianshou songae

TREE HUGGER  A newly identified mouse-sized mammal species, Xianshou songae, lived in Jurassic forests and has helped scientists redefine the mammalian family tree. 

Zhao Chuang

By Meghan Rosen

- More than 2 years ago

Modern mammals’ ancestors may have emerged millions of years earlier than scientists suspected — around the time the first dinosaurs roamed the Earth.