Two new species of anhingas are described from upper Miocene–Pliocene (Huayquerian) sediments of southwestern Amazonia, increasing the known diversity of these birds to two genera and at least three, perhaps four, species in these deposits. The new species described here are respectively the largest and the smallest species of Anhingidae known to date. The associated fossil fauna, including gigantic crocodiles and turtles, suggests a flooded paleoenvironment, with large bodies of fresh water surrounded by open vegetation, interspersed by forests.