Ancient fossil from China reveals animal-microbe partnerships dating back 550 million years

We often think of microbes as organisms that live around us, like the Salmonella bacteria and flu viruses that cause illness. But some of our most intimate relationships are with the microbes living inside us.

The Conotubus fossil is a small tube-shaped organism that lived around 550 million years ago. Most likely it was a soft-bodied animal resembling a worm. (Author), CC BY We often think of microbes as organisms that live around us, like the salmonella bacteria and flu viruses that…