The fossil plants found in the Eocene Florissant Formation and Green River Formation are preserved with a level of detail that allows one to closely examine traces of insect feeding damage. Levels (amounts) and patterns (abundance of various types) of fossilized insect feeding damage from Florissant and the middle Eocene Green River Formation were compared. This allowed for a detailed examination of feeding damage and provided an opportunity to examine long-term patterns of change in insect herbivory during a period of climate fluctuation. Samples including 624 fossil leaves from Florissant and 584 fossil leaves from the Green River Formation were...