Plant-arthropod interactions and associated entomofauna in Permian and Triassic flora from southwestern Gondwana

CARIGLINO, B.; LARA, M.B.; MOISSAN, PHILIPPE

Buenos Aires

Congreso; XII Congreso de la Asociación Paleontológica Argentina; 2021

APA

Plant-arthropod interactions, especially those involving insects, are among the most common biotic relationships, both in diversity and abundance. The fossil record reflects these associations as damage traces on the leaves, stems, seeds, as well as other plant organs, allowing researchers to identify the type of interaction and, sometimes, infer about the likely producer. Here, we present an update of the current knowledge of Permian and Triassic floras with evidence of arthropoddamage from southwestern Gondwana and appoint other numerous units with high potential for plant-arthropod interaction studies. When available, we also add information about the associated entomofaunas present at the same unit, as they offer a unique opportunity for inferences about the producers of the traces. It is currently accepted that the widely dominating Glossopteris floras from the Southern Hemisphere were already declining before the end-Permian extinction event, and the subsequent restoration of the ecosystems by gymnosperm-dominated floras remained rare until the Middle Triassic worldwide. Likewise, a faunal turnover instead of a mass extinction seems to be a more adequate explanation for changes in insect faunas, at least at the order or family levels. Preliminary observations from several of the units herein considered, indicate an overall herbivory preference for glossopterids during the Permian, whereas a wider arrange of plant taxa, including umkomasiales, ginkgoales, cycadales and conifers, were utilized by the insects during the Triassic. Despite the change of the preferred plant hosts, all feeding and reproductive strategies (i.e., external feeding, piercing and sucking, galling, mining and oviposition) are found in both time periods, pointing to the re-establishment of even the more specialized strategies by a renewed, ?modern? invertebrate fauna in the latest Middle Triassic. With this contribution, we hope to inspireother researchers to consider looking for evidence of arthropod damage in fossil floras from a time interval of major interest due to salient biotic and abiotic events of regional and global significance, some of which probably acted as key drivers controlling the interactions between plants and insects.