Overview
- The peer-reviewed study, published Thursday in PLOS ONE, confirms a Lystrosaurus embryo preserved in an egg about 250 million years old.
- Synchrotron X-ray CT at the European Synchrotron Radiation Facility let researchers see an unfused lower jaw, a sign the animal died before hatching.
- The team concludes the eggs were soft-shelled and rich in yolk, which helps explain why such eggs almost never fossilize.
- Large, yolk-fed eggs likely produced well-developed hatchlings that could feed themselves and reproduce sooner, a strategy the authors argue helped Lystrosaurus dominate after the End-Permian mass extinction.
- The fossil was found in 2008 in South Africa’s Karoo Basin by preparator John Nyaphuli during a field trip led by Jennifer Botha, and modern scanning finally solved the puzzle.