Patterns of insect-mediated damage in a Permian Glossopteris flora from Patagonia (Argentina)

A total of 2523 fossil plant specimens from the La Golondrina Formation (Permian, Santa Cruz Province, Argentina) were examined in order to assess the diversity, frequency and representation of insect damage. Although no evidence of arthropod bodies have been found in the unit, their past presence is recorded through various types of plant-insect interactions, involving oviposition, external feeding, piercing and sucking, galling, and potential mine structures. Results show that at least 186 specimens (all of them plant leaves) suffered from some type of insect herbivory. Among the many damage types identified, some of them recognized for the first time in Gondwanan floras, oviposition and external feeding occurred most frequently, followed by piercing and sucking and galling. Glossopterid foliage was the preferred target over the rest of plant groups, and it was common to find more than one type of damage on the same leaf, suggesting these were exploited for multiple purposes by the insects. Compared to the Northern Hemisphere Permian floras, the La Golondrina Formation herbivory levels were low, and similar to those of other Glossopteris floras from Gondwana.