News > 1.6-billion-year-old steroid fossils hint at a lost world of microbial life

1.6-billion-year-old steroid fossils hint at a lost world of microbial life

Molecular fossils found in ancient sedimentary rocks indicate the presence of primitive eukaryotes that dominated aquatic ecosystems from 1.6 billion to 800 million years ago. Remnants of protosteroids, produced by primordial eukaryotes, were detected in rock samples worldwide. Previously, the scarcity of eukaryote fossils led scientists to speculate that bacteria dominated early ecosystems. The discovery provides insights into the evolution of complex life on Earth.