EARLY GRASS PALEOECOLOGY IN THE PALEOCENE-EOCENE OF THE SAN JORGE BASIN, ARGENTINE PATAGONIA

STILES ELENA; STRÖMBERG CAROLINE; ERRA GEORGINA ; GELFO JAVIER; GOIN FRANCISCO ; KOHN MATTHEW; MADDEN, RICHARD; TRAYLER ROBIN; BAUZA NICOLAS; GALLAHER TIMOTHY

Encuentro; 27th EAA Annual Meeting; 2021

Modern grasses in the family Poaceae exhibit exceptional taxonomic and ecological diversity, with grassland-dominated habitats covering about 40% of Earth’s land surface. Grasslands today occur in a range of temperate to tropical ecosystems, spanning low to high altitudes and wet to arid climates. However, because of the scant fossil record of grasses before the global Oligocene-Miocene spread of grasslands, the ecology of early grasses and their environmental affinities remain poorly understood. To address this gap, we analyze phytolith assemblages extracted from sediment samples collected at the Estancia Las Violetas locality to reconstruct the vegetation of the late Paleocene - early Eocene Rio Chico Group in the San Jorge Basin of Argentine Patagonia. The coastal lowland deposits of the Las Violetas and Las Flores formations of the Rio Chico Group, dated from 57.9±1.1 Ma to