Latest Oligocene (late Chattian) environmental transitions revealed by plant-insect interactions preserved in plant assemblages from Wind Brickyard, Eger, Hungary

Abstract

Plants and insects are fundamental components of terrestrial ecosystems; evidence of their interactions (preserved as trace fossils on leaves) provides valuable insights into past environments. The Wind Brickyard succession in Hungary (Central Paratethys), of latest Oligocene age, offers a rare opportunity to study well-preserved evidence of plant-insect interactions and palaeoclimate across three plant-bearing intervals. Coinciding with the Late Oligocene Warming Event and the onset of the Miocene Glaciation, the Wind Brickyard assemblages capture palaeoecological responses to climate change, filling a critical knowledge gap in European palaeoecosystems. By integrating herbivory analysis and CLAMP-based palaeoclimate reconstructions, this study contributes to our understanding of how palaeoenvironmental and palaeoclimatic factors shaped latest Oligocene biodiversity over time. In this study, a total of 1310 fossil leaves from three different stratigraphic intervals were analyzed. Thirty-three, mostly generalized, damage types were documented. The greatest damage frequency and richness occurred in the upper of the three levels, which is represented by mainly azonal elements of riparian and swamp vegetation. This higher proportion of specialized insect damage is connected to elements of the zonal vegetation. These findings suggest that environmental changes and host plant zonality influenced the greater damage richness and frequency in the upper layer, highlighting significant ecological shifts close to the Oligocene-Miocene boundary.