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

• DOI: 10.1126/science.abo3594
• Publication Date: 2023-08-23T17:32:30Z
• Authors: F. Robin O’Keefe; Regan E. Dunn; Elic M. Weitzel; Michael R. Waters; Lisa N. Martinez; Wendy J. Binder; John R. Southon; Joshua E. Cohen; Julie A. Meachen; Larisa R. G. DeSa...; Matthew E. Kirby; Elena Ghezzo; Joan B. Coltrain; Benjamin T. Fuller; Aisling B. Farrell; Gary T. Takeuchi; Glen MacDonald; Edward B. Davis; Emily L. Lindsey
• Keywords: Megafauna; Stadial; Aridification; Early Pleistocene

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