Fossil feeding traces—
such as chewed margins and holes in leaves—
provide key evidence for reconstructing
the long-standing interactions and coevolution
between plants and small animals (including insects and mites)
that have continued since the Early Devonian,
cross an immense timescale of about 470 million years.
Have you ever noticed leaves that have been eaten by something? Plants on land interact with many kinds of animals, and leaves in particular preserve a variety of traces—chewed edges, small holes made by sap-sucking insects, and even nests constructed by cutting and stitching leaf pieces together. Many of these marks were made by small animals such as insects and mites.
Over the course of evolution, animals have developed many different ways to use plants. Plants, however, have not simply been passive victims; they have evolved defenses such as thorns and chemical toxins. In this way, plants and animals have strongly influenced each other’s evolution.
This relationship began at least as early as the Early Devonian, when primitive plants first lived on land, and it has continued without interruption to the present day. An important key to understanding this long history is “fossil feeding traces”—plant fossils that preserve evidence of insect damage.
Just as tooth marks can help identify an individual, the shape of feeding traces can provide clues about what happened and who was involved. Around the world, researchers are using these fossils to reconstruct the history of plant–insect interactions across an immense timescale of about 470 million years.
By applying the classification framework for
traces on plant impression and compression fossils (FFGs and DTs),
researchers can investigate how plant–herbivore interactions
have changed through time and across different fossil localities.
Plants preserve many kinds of traces left by animals. Because trace shape reflects differences in mouthpart morphology and behavior, these traces provide a window into the ecology and evolution of ancient herbivores that cannot be observed directly.
Dr. Conrad Labandeira and colleagues developed a classification framework for traces on plant impression and compression fossils based on morphology as a proxy for behavior (Labandeira et al., 2007). Broad categories are defined as Functional Feeding Groups (FFGs), which include both feeding and oviposition damage, and finer variants within each group are designated as Damage Types (DTs).
Across nine FFGs, more than 400 DTs have been recognized as of March 2026. Using FFGs and DTs, researchers can quantify feeding-trace diversity and track how plant–herbivore interactions changed through time and across different fossil sites.