Ischyrorhynchus

Ischyrorhynchus is an extinct genus of probable iniid river dolphins from South America. Only one species has been described, Ischyrorhynchus vanbenedeni, which was named by Ameghino in 1891. The Paleobiology Database dates the species to between the Tortonian and Zanclean ages, roughly 11.6 million to 3.6 million years ago. Its classification has long been uncertain: the genus is usually grouped with the river dolphin family Iniidae, but it has also been treated as a possible member of the Platanistidae, and the related genus Saurocetes has been suggested to be a synonym of it, so the name sits at the center of a small taxonomic puzzle among South American fossil river dolphins.