Amazon river dolphin
The recognition of "I. araguaiaensis" as a distinct species is still debated. It was originally distinguished from the Amazon river dolphin ("Inia geoffrensis") in January 2014 on the basis of nuclear microsatellite and mitochondrial DNA data as well as differences in skull morphology (it generally has a wider skull). It also differs from the Amazon and Bolivian river dolphins in the number of teeth per hemimandible (24–28 versus 25–29 and 31–35, respectively).