Lazarus Kgasi walks with ease across a gently rolling landscape about an hour's drive outside of Pretoria, South Africa. A few trees are sprinkled here and there but it's mostly grass. Kgasi, a tall ...

For more than 90 years, scientists have puzzled over an unusual 280 million-year-old reptilian fossil discovered in the Italian Alps. It’s unusual because the skeleton is surrounded by a dark outline, ...