How Ancient Microbes Rode Bug Bits Out to Sea

Between 535 and 520 million years ago, a new kind of biological litter began collecting in the ancient oceans of the Cambrian period. Exoskeletons helped early arthropods expand in huge numbers throughout the world’s oceans. And tiny exoskeleton fragments may have allowed some of the most important microbes in the planet’s history to set sail out into the open ocean and change the world forever.