ABSTRACT A global wave of megafauna extinctions occurred between 50,000 and 10,000 years ago, impacting numerous large continental mammals that are crucial to ecosystem dynamics. Among these are the gomphothe res, Cuvieronius hyodon (Fischer, 1814) and Notiomastodon platensis (Ameghino, 1888), two species closely related to modern elephants. Cuvieronius migrated from North to South America during the Pleistocene. Both species became extinct between 15,000 and 7,000 years ago. Proposed explanations for these extinctions include hunting by early human populations in South America and climatic fluctuations during the Pleistocene. We tested the climate change hypothesis over the past 120,000 years as a critical factor related to the extinction of South American gomphotheres. Our analysis relied on paleoclimatic models spanning the Last Interglacial (120,000 years before present - YBP), the Last Glacial Maximum (21,000 YBP), the Oldest Dryas (18,000 YBP), the Younger Dryas (13,000 YBP), and the Middle Holocene (6,000 YBP), marking the last known occurrence of the Pleistocene megafauna. Geographic distribution records of both species were mapped using data from the scientific literature and open databases. Subsequently, suitable climatic areas for both species in South America were identified through species distribution model projections across these five paleoclimatic periods. Our models revealed significant fragmentation of suitable areas for both species during these critical events. This fragmentation likely contributed to their extinction, possibly exacerbated by additional factors such as the establishment of early human populations in the continent
