The fossil of a termite trapped in amber is the earliest example of mutualism between an animal and the microbes in its gut.
One hundred million years ago a termite was wounded and its abdomen split open. The resin of a pine tree slowly enveloped its body and the contents of its gut.
In what is now the Hukawng Valley in Myanmar, the resin fossilized and was buried until it was chipped out of an amber mine. The resin had seeped into the termite’s wound and preserved even the microscopic organisms in its gut. These microbes are the forebears of the microbes that live in the guts of today’s termites and help them digest wood.