Pollen sources in studies of camelid coprolites from Patagonia (Argentina).

VELÁZQUEZ NADIA JIMENA; BURRY LIDIA SUSANA; FUGASSA MARTÍN

Morillo de Tou

Encuentro; 3rd Young Scientists Meeting Global Challenges for our common future: a paleoscience perspective; 2017

Pyrenean Institute of Ecology, Spanish National Research Council (IPE-CSIC), PAGES (Past Global Changes)

Palynological studies on Holocene coprolites provide information about palaeodiets, seasonality and palaeoenvironment. The elucidation of the source of the coprolites pollen is a main issue to interpret what and how past facts happened. The aim of this study is to analyze the source of the pollen of present day Lama guanicoe feces and camelid coprolites. For this, feces and coprolites post-depositing pollen contamination and the plant surface contamination, which are part of the L. guanicoe´s diet, were evaluated. The feces and plant were collected in the area near the sites CCP5 and CCP7 (47°57´S; 72°05´W, 900 mamsl), Perito Moreno National Park. Moreover, coprolites collected in CCP5 and CCP7 dated by 14C between ca. 9640 and 2740 yr BP, were studied. Feces and coprolites were divided into outer and inner subsamples and extracted pollen from both fractions for analyses. Pollen extraction of the plant surface of Mulinum spinossum, Empetrum rubrum, Senecio filaginoides and Nardophyllum obtusifolium, were done. The results showed differences in the pollen concentration between subsamples of feces that could be linked with the pollination season. Coprolites evidenced a greater Nothofagus (anemophilous) pollen concentration in the outer surface than in the inner ones and certain taxa were only registered in a single part. Plant surface showed a high concentration of pollen of the mother plant, and a low concentration of other anemophilous and zoophilous taxa. A separate pollen analysis of the outer and inner parts of modern feces and coprolites yields information referred to pollen contamination; thus, the diet items of the vegetation not consumed by the organisms can be discriminated. These results are a new contribution to palaeoecological studies of Patagonia during the Holocene and highlight the importance of considering the taphonomic processes, which would be acting in the building of the pollen record of modern feces and coprolites.