Closed-canopy rainforests are a vital part of Earth’s modern ecosystems, but tropical plants don’t preserve well in the fossil record so it is difficult to tell how long these habitats have existed and where rainforests might have once grown. Instead, scientists look to the diets of extinct animals, which lock evidence of the vegetation they ate into their teeth. A new study finds that the paradigm used to identify closed-canopy rainforests needs to be reassessed.
