PREDATOR-PREY RELATIONSHIPS INFERRED BY COPROLITE PHYTOLITH ANALYSIS FROM ARGENTINE PATAGONIA

BENVENUTO, MARÍA LAURA ; VELÁZQUEZ, NADIA J.; MARTÍNEZ TOSTO, ANA CECILIA; FERNÁNDEZ, NATALIA; CIVALERO, MARÍA TERESA; OSTERRIETH, MARGARITA; BURRY, LIDIA SUSANA

Kiel

Encuentro; 27th EAA Annual Meeting (Kiel Virtual, 2021); 2021

Knowing about past biological interactions is possible thanks to the study of coprolites found in archaeological sites. Evidence ofherbivores consumption by omnivorous organisms was found in Patagonia through bone remains studies. With the aim to recognizethe limitations and potentialities of the phytolith analysis to infer predator-prey relationships, a comparative analysis among thecontent of phytoliths obtained from omnivores and herbivores coprolites was performed. The coprolites were found in the archaeologicalsite Cerro Casa de Piedra 5, Perito Moreno National Park, Patagonia, Argentina, in an archaeological layer dated to 7,402cal BP. According to their morphological features and content, the coprolites were assigned to omnivores organisms and camelids.Samples were rehydrated, filtered, concentrated, dried, and mounted in immersion oil. Counting and identification of phytoliths weremade under optical microscope. The results showed the dominance of phytolith association of the subfamily Pooideae in the omnivoreand camelid coprolites suggesting that the grasses were part of the diet of these organisms. This result was even confirmedthrough pollen and plant remains analyze. Also, isolated and articulated phytoliths and preserved silicified cells within the producingplant tissue were observed in camelid coprolites, while in omnivore samples only isolated phytoliths were observed. The presenceof isolated phytoliths in these last samples could indicate that the phytoliths consumed could have been subjected to alterationprocesses, such as chewing, food processing prior to consumption, digestion or were indirectly incorporated by the consumptionof guanaco viscera, exposing phytoliths on more than one occasion to the alteration processes. Future studies on the qualitativeand quantitative production of phytoliths in species linked to the diet of herbivores and omnivores as well as on the effects oftaphonomic processes from the digestive systems of consumers may contribute to the knowledge of past biological interactions.