This 250-million-year-old fossil proves mammal ancestors laid eggs

illuminem summarises for you the essential news of the day. Read the full piece on CNN or enjoy below:

🗞️ Driving the news: Scientists have discovered the fossilized embryo of Lystrosaurus in South Africa, providing the first direct evidence that early ancestors of mammals laid eggs

🔭 The context: The fossil dates back around 250 million years, shortly after the catastrophic mass extinction known as the Permian–Triassic extinction event, often called the “Great Dying,” when roughly 90% of life on Earth disappeared
• Researchers used advanced scanning technologies, including synchrotron X-rays, to analyze the embryo
• They found that its jaw bones were not fully fused, a developmental trait seen today in embryos of egg-laying animals like birds and turtles

🌍 Why it matters for science: The fossil provides insight into how species adapted to extreme environmental stress following Earth’s largest mass extinction
• Understanding these survival strategies helps scientists study how ecosystems recover after planetary disruptions such as climate shifts, habitat loss, and biodiversity collapse

⏭️ What’s next: Researchers now plan to investigate when mammals transitioned from egg-laying to live birth and how lactation first evolved, possibly initially to keep leathery eggs moist rather than to feed newborns

💬 One quote: “This is the first time we can say, with confidence, that mammal ancestors like Lystrosaurus laid eggs,” - researcher Julien Benoit

📈 One stat: The Permian–Triassic extinction event wiped out about 90% of all species, making it the most severe extinction event in Earth’s history

See on illuminem's Data Hub™ the sustainability performance — carbon credit purchases, total emissions, and climate targets of thousands of companies

Click for more news covering the latest on biodiversity