Rocks Kept in a Warehouse For Decades Held a Major Clue to Complex Life

Scientists identified more than 12,000 microfossils in 1.75-billion-year-old mudstone cores from northern Australia.

Among them are the oldest known eukaryote fossils, offering rare evidence of early complex life.

The discovery helps researchers test how eukaryotes evolved and whether oxygen was needed at the start of that process.

The cores, studied decades after being stored in a Darwin warehouse, also reveal details of an ancient inland sea environment.