Nature World News | 17.04.2026 07:47Mammal ancestors laid eggs, a revelation cemented by a groundbreaking 250-million-year-old fossil egg unearthed in South Africa. This Lystrosaurus embryo fossil provides the world's first direct proof of therapsid reproduction, emerging just after the Permian-Triassic extinction that erased 90% of Earth's species 252 million years ago.
