Atacama Desert fossil discovery suggests ancient humid conditions

Researchers from the University of Arizona and other institutions have discovered a fossilized tooth in Chile that suggests the Atacama Desert was once significantly wetter than it is today. The tooth belongs to Cardiatherium, an extinct genus believed to be a direct ancestor of modern capybaras.

Found in the Bahía Inglesa Formation, the fossil dates back approximately 8.8 million years to the late Miocene epoch. Its presence in the Atacama Desert—one of the oldest and driest non-polar deserts on Earth—indicates that the region along the Pacific coast experienced much more humid conditions in the past.