9-Million-Year-Old Capybara Tooth From Chile Hints at Unexpectedly Wet Conditions in the Ancient Atacama Desert

A nine-million-year-old capybara tooth discovered in the Atacama Desert in Chile suggests that the arid region may have once experienced wetter conditions, challenging the notion that it is one of the world's oldest continuously dry areas. Capable of thriving near rivers and ponds, capybaras are now commonly associated with wetland environments east of the Andes.

However, the fossilized tooth, found at a site called El Morro in the Bahía Inglesa Formation, represents the oldest known record of capybara ancestors in coastal Chile. The researchers, led by Priscilla Martinez from the University of Arizona, propose that capybaras likely bypassed the Andes by traversing low-elevation wetlands connecting their original habitat to northern South America.

The discovery of phytoliths from palms and other flowering plants indicates that the Atacama Desert may have had a significantly different climate nine million years ago, potentially supporting capybara populations. This finding challenges existing ideas about the Atacama's history and underscores the region's capacity for climate change throughout its history.