Emergence of Hippopotamidae: new scenarios

Molecular data analyses blew the problem of hippo origins up to the level of a broader question: cetacean and artiodactyl relationships. Recently, new morphology-based studies strongly supported a hippo origin within Miocene bothriodontines, which are selenodont anthracotheres. Based on these results, two new scenarios for hippo emergence are proposed here. Palaeoenvironmental and evolutionary issues related to these scenarios are discussed.