A Miocene relative of the Ganges River dolphin (Odontoceti, Platanistidae) from the Amazonian Basin.

The article discusses various toothed whales found in freshwater habitats including the Amazon River dolphin, the Indus and Ganges river dolphins, and the Yangtze river dolphin. It says that the said genera of dolphins are identified as part of different families due to their molecular and morphological differences. It mentions that the existing habitat of freshwater dolphins might be attributed to the independent episodes of freshwater colonization. It states that various fragment fossil specimens such as jaw or isolated tooth fragments were discovered and believed to be related to existing genera of river dolphins. It cites the Platanistinae fossil record from the early Miocene period which was found at the coastal deposits of Oregon.