Did ice age beasts carve vast caves in South America?
https://www.nature.com/articles/d41586-025-00216-x
nonpaywalled: https://archive.fo/Lp9Y2
* who/what cut ancient tunnels in sandstone in Brazil/nearby nations
* early twentieth century attributed to ancient Indigenous groups
* h/e research in past decade coalesced around theory the caves were carved by extinct megafauna
* South Am. sloth that lived between 4M - 12.k years ago
* 3m long, 1.5k kg weight