Abstract Detail

Germinating Ideas - Lightning Talks

Stiles, Elena [1], Stromberg, Caroline [1], Erra, Georgina [2], Gelfo, Javier N. [3], Goin, Francisco [3], Kohn, Matthew [4], Madden, Richard H. [5], Trayler, Robin B.  [6], Bauzá, Nicolás [7], Gallaher, Timothy [8].

Paleocene - Eocene vegetation and early grass ecology in the San Jorge Basin of Argentine Patagonia.

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 <50.6±0.8 Ma, produced phytolith assemblages comprising among the oldest occurrences of grass phytoliths in the fossil record of South America. Preliminary results of phytolith analyses suggest that early grasses in the Paleocene and Eocene of the San Jorge Basin occurred in low abundances in palm and dicot dominated forests. Further analyses of the studied phytolith record will allow us to (1) reconstruct the vegetation and, thus, the ecological context of early grasses, and (2) test for broad floristic changes across the Paleocene - Eocene transition in southern South America, contributing to our understanding of the impact of this period of extreme global warming on terrestrial ecosystems in the Southern Hemisphere.

1 - University Of Washington, Department Of Biology, Life Sciences Building, Box 351800, Seattle, WA, 98195, United States
2 - CONICET - Museo de La Plata, Geociencias, Avenida del Petróleo Argentino s/n (e/ 129 y 143), Buenos Aires - La Plata , B1900FWA, Argentina
3 - CONICET - Museo de La Plata, División Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque s/n, La Plata, B1900FWA, Argentina
4 - Boise State University , Geosciences, ERB 5165, ID, 83725, USA
5 - University of Chicago , Org.Bio./Anatomy, Chicago, IL, 60637, USA
6 - UC Merced, Natural Sciences, 5200 North Lake Rd, Merced, CA, 95343, USA
7 - CONICET - Museo de La Plata, División Paleontología Vertebrados, Universidad Nacional de La Plata, La Plata, B1900FWA, Argentina
8 - University Of Washington, Biology, 24 Kincaid Hall, Box 351800, Seattle, WA, 98195, United States


Presentation Type: Germinating Ideas Lightning Talk
Session: LT2, Germinating Ideas - Lightning Talks II
Location: Virtual/Virtual
Date: Friday, July 31st, 2020
Time: 1:05 PM
Number: LT2008
Abstract ID:602
Candidate for Awards:None

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