Mammal hairs preserved in amber specimen ARC2-A1-3. a – First fragment; b – Line drawing of first fragment; c – Second fragment; d – Line drawing of second fragment; e – Close-up of second fragment to show the cuticular surface.

About 100 million years ago, in a coastal forest located in what is today southwestern France, a small mammal skittered up the trunk of a conifer tree. As it did so it lost a few of its hairs, and this minor event would have been entirely unremarkable if two of those hairs had not settled in some tree sap and, in the course of time, become entombed in a piece of amber which has only recently been