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, ...

The small, plant-eating Lystrosaurus thrived post-extinction, while its predators suffocated to death. Its eggs played a critical role. New analysis shows several families of dinosaurs were likely ...

That matters because Lystrosaurus was no obscure reptile-like relic. It was one of the great survivors of the end-Permian mass extinction, the catastrophe about 252 million years ago that wiped out ...

(CNN) - Researchers said a fossil found in South Africa proves for the first time that mammal ancestors laid eggs. The fossil belongs to a tightly-curled embryo of a Lystrosaurus. The Lystrosaurus is ...