PHYTOPHAGY ON FOSSIL FERNS FROM ARGENTINA (PALO PINTADO FORMATION, LATE MIOCENE): A REVIEW OF THEIR FOSSIL RECORD AND ICHNOTAXONOMY

Evidence of insect-fern interactions are described for the first time from late Miocene strata of Salta Province, Argentina. Two ichnospecies are defined to include fossil traces of surface feeding and hole feeding, located between the secondary veins and adjacent with the primary vein of two species of fossil ferns, Blechnum serrulatiformis Anzotegui & Horn and Thelypteris interrupta (Willd.) Iwatsuki. The first ichnospecies corresponding with surface feeding presents oblong traces and both ends are rounded; occupying the entire intercostal space. This type of phytophagy is found for the first time in the fossil record of ferns. The second ichnospecies is similar in shape and location to the previous ichnotaxon, except that all herbivorized tissues are absent. At last, a review of the fossil record of insect-fern associations is performed.