Genetic analysis has previously hinted that there are several species of Amazon river dolphin, and now differences in skull shape have added to the evidence

Life 11 May 2022

An Amazon river dolphin (Inia geoffrensis geoffrensis) in the Rio Negro, Brazil

Kevin Schafer

Evidence is mounting that the Amazon river dolphin (Inia geoffrensis), one of only a few remaining dolphin species that live purely in fresh water, is in fact multiple species.

New research reveals that the skulls of these dolphins vary substantially between populations in different river basins in South America. If their physical differences represent evolutionary adaptations rather than just random variation within a population, there could be profound conservation implications for these animals, which have declined sharply in recent …