A 16-million-year-old fossil skull of a river dolphin was unveiled by scientists on Wednesday in Peru.
The dolphin, according to a study published in the journal Science Advances, once swam in waters that are now the Amazon. Its closest living relatives are believed to be the South Asian River dolphin found in India's Ganges.
A Paleontologist Rodolfo Salas said the skull, measuring 3 to 3.5 meters long, belonged to the largest dolphin known to have inhabited the waters of South America.
Scientists found the fossil during a 2018 expedition sponsored by the National Geographic Society at the Napo River.
"This dolphin is related to the dolphin of the Ganges river in India," Salas said. He further added that the one found in Peru is much bigger than its living relatives in Asia.
Salas also reported that the ancestors of both dolphins formerly lived in the ocean.
"This allowed them to occupy large ocean spaces near the coasts of India and South America. These animals lived in the freshwater environments both in the Amazon and India. Sadly, they became extinct in the Amazon, but in India they survived," Salas further added.