A human role in Andean megafaunal extinction?

• Published in: Quaternary science reviews Vol. 205; pp. 154 - 165
• Main Authors: Raczka, M.F., Mosblech, N.A., Giosan, L., Valencia, B.G., Folcik, A.M., Kingston, M., Baskin, S., Bush, M.B.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2019
• Subjects: Andes; Deglaciation; Ecuador; Extinction; Fossil pollen; Human arrival; Pleistocene megafauna; Sporormiella; Ecuador; Andes; Sporormiella; Extinction; Fossil pollen; Deglaciation; Human arrival; Pleistocene megafauna
• ISSN: 0277-3791; 1873-457X
• DOI: 10.1016/j.quascirev.2018.12.005

A new fossil pollen, Sporormiella, and sediment chemistry record from Lake Llaviucu, Ecuador, spanning the period from 16,280–9000 years Before Present, provides a high-resolution record of paleoecological change in the high Andes. The deglacial transition from super-páramo through páramo grasslands, to Andean forest is traced, with near-modern systems being established by c. 11,900 years ago. It is suggested that forest elements probably existed in microrefugial populations close to the ice front. Sporormiella is used as a proxy for megafaunal abundance, and its decline to background levels is inferred to indicate a local extinction event at c. 12,800 years ago. About 1800 years prior to the extinction, charcoal becomes a regular sedimentary component in this very wet valley. An early date for human activity in the valley is suggested, with the direct implication of humans in the extinction of the megafauna. •Analysis of fossil Sporormiella showed the local extinction of megafauna at c. 12.8 k cal BP in Ecuador's Llaviucu valley.•Increased fire frequency at c. 14.6 k cal BP is interpreted as a signal of early human activity.•Humans and megafauna co-existed for about 1.8 k years in the study region.•We infer that humans caused the ultimate extinction of megafauna in this portion of the Andes.