250-million-year-old fossil provides proof that our mammal ancestors laid eggs

Scientists studying a 250-million-year-old fossil say they can now say with confidence that our mammal ancestors laid eggs. The fossil, found in South Africa, belonged to an embryo of the Lystrosaurus, which famously survived a mass extinction event known as the "Great Dying."

Here & Now's David Folkenflik speaks with Caroline Abbott, a paleobiologist with the University of Chicago.