These new fossils bring to light a critical missing link and enrich our understanding of the gradual evolution of the mammalian middle ear.

Both studies are like redrawing a gigantic map of species, removing some of the pinned lines between shuotheriids and other groups, and creating new ones.

This kind of remapping helps to show how traits developed over time, independently or in sync, and from there the different environmental pressures that may have contributed to them.

In other words, the research adds to the how and why of how mammals evolved – all thanks to little scurrying creatures from hundreds of millions of years ago. It’s also another reminder of how new fossil discoveries, and new studies of those fossils, can add clarity to evolutionary mysteries.