Boto

A few botos exist exclusively in fresh water, and these are often considered primitive dolphins.

The botos are a paraphyletic group, defined largely by their evolutionary convergences.

The costero (S. guianensis) is distributed in the Atlantic, from Florianópolis in Santa Catarina, Brazil, and northwards.

Burmeister's porpoise is marine and lives from Santa Catarina to the south.

[1] The Araguaian river dolphin (I. araguaiaensis) is a newly identified species native to the Araguaia-Tocantins basin of Brazil.