The new species was discovered from the Araguaia River basin of Brazil and researchers have proposed the name Araguaian Boto, or Boto-do-Araguaia. It was discovered by carrying out series of molecular and morphological characters test which revealed that it diverged from other South American river species more than 2 million years ago, researchers said.
About 1,000 of these creatures are estimated in the Araguaia river basin, ‘BBC News’ reported.
By analysing DNA samples from dozens of dolphins in the Araguaia and Tocantins rivers, researchers concluded the Araguaia river creature was indeed a new species.
“We looked at the mitochondrial DNA which is essentially looking at the lineages, and there is no sharing of lineages,” said lead author Dr Tomas Hrbek, from the Federal University of Amazonas.
“The groups that we see, the haplotypes, are much more closely related to each other than they are to groups elsewhere. For this to happen, the groups must have been isolated from each other for a long time,” Hrbek said.
“The divergence we observed is larger than the divergences observed between other dolphin species,” he said.