Hidden in plain sight for millions of years, a fossil no larger than a fingernail has emerged from the vast Gobi Desert, raising big questions about early life on Earth. What makes it so unusual isn’t immediately obvious. A tiny fossil discovered in Mongolia’s Gobi Desert has revealed a new species of early mammal that lived around 90 million years ago. The find is already refining what scientists know about the earliest relatives of placental mammals. The specimen wa... [2815 chars]