Costa Rica uncovers megafauna fossils
Pleistocene mastodon and sloth remains recovered
Costa Rica’s National Museum announced the recovery of fossil remains belonging to two Pleistocene megafauna species in Cartago province: Cuvieronius, a mastodon relative, and Eremotherium, a giant ground sloth. The find followed a tip from a local resident and prompted the museum’s natural history team to carry out 13 excavation-and-rescue operations at a river-adjacent site under difficult terrain conditions. To date, researchers have retrieved 49 fossil pieces, including a complete tusk measuring 1.60 metres, a tusk fragment, vertebrae, a femur, phalanges, ribs and other bones now undergoing identification.
Preliminary geological and sediment-layer analysis places the remains in the late Pleistocene, with estimated ages between about 10,000 and 40,000 years. The sediments suggest the area was once part of a river system or floodplain—favorable contexts for bone preservation—and the co‑occurrence of the two species could offer fresh insights into ecosystems and species interactions in prehistoric Central America.
Museum officials described the discovery as among the most significant paleontological finds in Costa Rica in decades. The site has been secured while further laboratory studies proceed, including planned radiocarbon dating and detailed sediment analysis to refine the fossils’ age and reconstruct the ancient environment. Conservators will prepare the material for in‑depth study, and authorities say some specimens may later be displayed to the public.
Researchers noted the role of community reporting in safeguarding the site and stressed that ongoing analysis may shed light on diet, habitat, preservation conditions and possible causes of death—factors relevant to broader debates about Pleistocene megafauna extinctions, including climate change and human impacts. The excavation adds to a growing body of evidence about prehistoric biodiversity in Central America and underscores the region’s potential for future paleontological discoveries.
