Why South America’s ancient mammals may have lost out to northern counterparts
Extinctions left fewer animals available to migrate north, a study suggests
![ancient North American and South American animals](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2020/11/102720_jb_extinction_feat_illio-opt1.jpg?fit=1028%2C579&ssl=1)
Roughly three million years ago, peccaries and other North American mammals (shown at left in this illustration) migrated south across the Isthmus of Panama into the land of ground sloths and armadillos, while these and other animals went north.
Guillermo Torres Carreño