Bernasso, a paleoforest from the early Pleistocene: New input from plant-insect interactions (Hérault, France)

Plants and insects have interacted for millions of years in terrestrial ecosystems and are essential to the function of the food web. These interactions can be classified based on different functional feeding groups and damage types, and provide information about the relationship between plants and insects. We focused this study on the Pleistocene deposit of Bernasso (Hérault, southern France). The Bernasso fossil leaf assemblage has been dated from 2.16-1.96 Ma and corresponds to a deciduous forest comprising both continental and Mediterranean species such as Carpinus orientalis Mill., Parrotia persica C. A. Mey. and Acer monspessulanum L., Sorbus domestica L., respectively. Twenty different plant species are represented by 590 fossil leaves among which more than 36% present insect damage. Thirty-nine different damage types were found with galling being the most prominent. These types of interactions enable discussion about the ecological settings that prevailed at this epoch (forest age, precipitation, temperature). For instance, the mean annual precipitation was certainly higher than today in the region. Moreover, the results of this study offer the possibility to get new insights into the ecological paleoforest community.