A bizarre fossil called Prototaxites, which was the largest life-form on land 400 million years ago, may have been a completely unknown form of multicellular life, according to a new study.

Life has found a home on Earth for around 4 billion years. That's a significant fraction of the universe's 13.77 billion-year history. Presumably, if life arose here, it could have appeared anywhere.

For hundreds of years, Africa has been the location of groundbreaking discoveries that have shaped researchers’ understanding of the Earth’s history. In the Sahara Desert, scientists uncovered ...