By examining art printed from woodblocks spanning five centuries, Hedges has identified the species responsible for making the ever-present wormholes in European printed art since the Renaissance. The hole-makers, two species of wood-boring beetles, are widely distributed today, but the "wormhole record," as Hedges calls it, reveals a different pattern in the past, where the two species met along a zone across central Europe like a battle line of two armies. The research, which is the first of its kind to use printed art as a "trace fossil" to precisely date species and to identify their locations, was published in the journal *Biology Letters* in November.
Hedges’ method has relevance not just to biology, but also to art history. "There are some situations in which a book or print's origin is unknown because a printing location was never added to the text," Hedges said. "Now that we know that different species of beetles existed in different locations in Europe, art historians can determine whether a book was from northern or southern Europe simply by measuring the wormholes."