Seasonality and desertification drove the global extinction of megafauna in the late Quaternary

• Published in: Quaternary science reviews Vol. 344; p. 108979
• Main Authors: Graipel, Maurício E., Lima-Ribeiro, Matheus S., Cherem, Jorge J., Momsen Miller, Paul R., Diniz-Filho, José A.F., Cáceres, Nilton C.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.11.2024
• Subjects: Climate change; Orbital cycles; Overkill hypothesis; Predation; Climate change; Overkill hypothesis; Orbital cycles; Predation
• ISSN: 0277-3791
• DOI: 10.1016/j.quascirev.2024.108979

The causes of megafauna extinction in the late Quaternary have long been a controversial subject, which may be related to the limitations of adequate information to evaluate global hypotheses related to climate change and the impacts of modern human dispersal. We propose a new global spatio-temporal approach using variations of Earth's orbital parameters and atmospheric CO2 levels as forcing factors for environmental and climate change with worldwide distribution. We analysed the overlap between 142 times-of-extinction of megafauna, and high obliquity (as a forcing factor for seasonality), low atmospheric CO2 levels (as a forcing factor for desertification), and the arrival of modern humans. We found that critical periods of seasonality and desertification intensified in the last 800 ka BP, and made the last 50 ka BP exceptionally severe in relation to the entire Quaternary. These critical periods significantly overlapped with 87% of extinctions in continental and connected islands, compared with 32.1% overlap of extinctions with the arrival of modern humans. In contrast the arrival of modern humans on isolated islands overlapped with 90.9% of the extinctions. The arrival of modern humans in continental regions had 81.3% of overlap with critical periods of climate change, suggesting that the synchrony observed between extinctions and the dispersal of modern humans in continental regions was driven by climate. •Critical periods of seasonality and desertification drove megafauna extinctions.•Connected islands showed an extinction pattern similar to continents.•Modern humans drove extinctions on islands isolated from the mainland.•Human dispersal was driven by climate in synchrony with extinctions.•Seasonality and desertification were exceptionally severe in the late Quaternary.