New Species of River Dolphin Discovered in Brazil

A new species of river dolphin has just been discovered by scientists in Brazil, making it the first new river dolphin to be discovered since the end of World War One.

Named after the Araguaia river, the species is the only fifth known of its kind to be found in the world.

According to the IUCN, there are only four known species, three of which are critically endangered.

Researchers believe that the creatures may have separated from other South American river species more than two million years ago.

"It is very similar to the other ones," said lead study author Dr. Tomas Hrbek from the Federal University of Amazonas, via the BBC. "It was something that was very unexpected, it was an area where people see them all the time, they are a large mammal, the thing is nobody really looked. It is very exciting."

Researchers believe this new discovery is similar to the Amazon river dolphin--also known as the pink dolphin or boton--noted to be one of the most intelligent of all the river species. However, scientists believe that this species separated two million years ago.

They've particularly discussed differences in the number of teeth and smaller frame between the Amazon river dolphin and the Araguaia river dolphin, which may suggest clues regarding genetic structure.

"It's exciting evidence for a previously unrecognised species within the ancient lineage of Amazon river dolphins," said Scott Baker of Oregon State University in Newport, via NewScientist.com. "Yet it's already rare, and its habitat is now fragmented by dams."  

However, at this time, scientists are still not entirely certain whether the discovery of the Araguaia river dolphin can be completely distinct from that of the Amazonian.

"In science you can never be sure about anything," Hrbek added, via the news organization.

What do you think?

More information regarding the study can be found via the journal PlOS One.