AP

SAO PAULO (AP) — Scientists say they have discovered the first new river dolphin species in nearly 100 years inhabiting the Araguaia River in Brazil's vast Amazon rainforest.

The discovery of the "Inia araguaiaensis" was officially announced earlier this week in a study posted on line by the Plos One scientific journal.

Biologist Tomas Hrbek works at the Federal University of Amazonas in the city of Manaus and is the lead author of the study. He says the new species is the third found in the Amazon region.

Hrbek said it "it was an unexpected discovery that shows just how incipient our knowledge is of the region's biodiversity."