The small, plant-eating Lystrosaurus thrived post-extinction, while its predators suffocated to death. Its eggs played a critical role.

The fossilized remains of a Lystrosaurus now answers the question scientists have asked for years: Did mammals once lay eggs?

Researchers studying a 250-million-year-old fossil have found the first ever proof that mammal ancestors laid eggs, with the discovery also shedding light on a remarkable survival story.

A remarkable discovery answers one of the greatest survival stories in Earth’s history—and a decades-old scientific mystery.

At a time when Earth was going through massive environmental changes and most species were wiped out by Siberian volcanic eruptions, some animals actually managed to survive the chaos. During this ...

Between 280 and 200 million years ago, a group of animals evolved which would eventually give rise to mammals, including humans: the therapsids. They were first described more than 150 years ago, ...

Researchers studying a 250-million-year-old fossil have found the first ever proof that mammal ancestors laid eggs, with the discovery also shedding light on a remarkable survival story. The fossil, ...