Riding on the back of another animal for getting around is something we’ve been good at for quite some time. Sitting yourself on another creature purely for transport is known as phoresy, and it’s pretty rare. Yet there are a lot of examples aside from humans on horseback. One unique case is that of a springtail riding a mayfly, since it’s only known from a16 million-year-oldamber specimen.
The tiny springtail had used its antennae to attach itself to the base of the mayfly’s wings for its journey. Unfortunately for the both of them, the mayfly picked an unwise resting spot and ended up encased in amber. The springtail may have tried to escape at the last moment—it was 50 micrometers (a 500th of an inch) away from its ride—but its efforts were in vain. Scientists think this probably still happens, but is just really hard to observe.