Goniodelphis

Goniodelphis is an extinct genus of iniid river dolphin whose only species, Goniodelphis hudsoni, is known from the waters of Florida during the Miocene epoch, roughly 14.9 million to 8.7 million years ago. Its fossils were recovered from just four phosphate mines in Polk County, Florida: the American Agricultural Chemical Company mine, Fort Green, Payne Creek and Gardinier. The genus was named by Allen in 1941, with G. hudsoni as its type. It was once assigned to the ocean dolphin family Delphinidae, but most authorities since the 1940s have placed it in Iniidae, the river dolphin family, and a 2010 study treated the genus as monophyletic.