Pre-Younger Dryas megafaunal extirpation at Rancho La Brea linked to fire-driven state shift.

Bibliographic Collection: 
Publication Type: Journal Article
Authors: O'Keefe, F Robin; Dunn, Regan E; Weitzel, Elic M; Waters, Michael R; Martinez, Lisa N; Binder, Wendy J; Southon, John R; Cohen, Joshua E; Meachen, Julie A; DeSantis, Larisa R G; Kirby, Matthew E; Ghezzo, Elena; Coltrain, Joan B; Fuller, Benjamin T; Farrell, Aisling B; Takeuchi, Gary T; MacDonald, Glen; Davis, Edward B; Lindsey, Emily L
Year of Publication: 2023
Journal: Science
Volume: 381
Issue: 6659
Pagination: eabo3594
Date Published: 2023 Aug 18
Publication Language: eng
ISSN: 1095-9203
Keywords: Animals, Archaeology, California, Desiccation, Ecosystem, Extinction, Biological, Fires, Fossils, Humans

The cause, or causes, of the Pleistocene megafaunal extinctions have been difficult to establish, in part because poor spatiotemporal resolution in the fossil record hinders alignment of species disappearances with archeological and environmental data. We obtained 172 new radiocarbon dates on megafauna from Rancho La Brea in California spanning 15.6 to 10.0 thousand calendar years before present (ka). Seven species of extinct megafauna disappeared by 12.9 ka, before the onset of the Younger Dryas. Comparison with high-resolution regional datasets revealed that these disappearances coincided with an ecological state shift that followed aridification and vegetation changes during the Bølling-Allerød (14.69 to 12.89 ka). Time-series modeling implicates large-scale fires as the primary cause of the extirpations, and the catalyst of this state shift may have been mounting human impacts in a drying, warming, and increasingly fire-prone ecosystem.

DOI: 10.1126/science.abo3594
Alternate Journal: Science