Fossil evidence of lichen grazing from Palaeogene amber

Abstract

Lichens are important in many modern terrestrial ecosystems, but their fossil record has been very sparse. This has limited the chances for finding any evidence of their interactions with animals in past ecosystems. Recently, the fossil record of lichens has improved significantly with the discovery of numerous new inclusions from European Palaeogene ambers. Here, we report the first fossil evidence of animal–lichen interactions from one new fossil from Bitterfeld amber of central Germany. A foliose fossil lichen, possibly belonging to the Physciaceae, exhibits three feeding marks and co-preserved invertebrate faecal pellets. To gain insights into this Palaeogene lichen-invertebrate interaction, we compared the fossil grazing damage and faecal pellets to those obtained from several extant lichen feeders, including mites, collembolans, psocopterans, coleopteran larvae and gastropods. The results of the grazing experiments suggest that gastropods and mites most likely caused the feeding marks preserved in the fossil lichen.