They are the largest known and lived in the Peruvian Amazon region. Its closest living relatives live in rivers in South Asia. An international research team led by the University of Zurich discovered the giant river dolphin fossil in Peru.
River dolphins are among the rarest modern cetaceans. Most of the existing species are in critical danger of extinction. The giant river dolphin fossil is the largest found and measures between 3 and 3.5 meters. The new species was named Pebanista yacuruna in honor of a mythical aquatic town. It is 16 million years old.
First of its kind
The findings are published in the journal Science Advances. The new species of dolphin belongs to Platanistoidea. It is a group of dolphins common in the world’s oceans between 24 and 16 million years ago.
“Sixteen million years ago, the Amazon was very different.” He affirms it it’s a statement the main author, Aldo Benites-Palomino, from the Department of Paleontology at the UZH. “It was covered by a large system of lakes and swamps called Pebas.” It included aquatic, semi-aquatic and terrestrial ecosystems.
“We found several giant shapes from the region, but this is the first dolphin of this type,” they add. “We were especially intrigued by its peculiar deep biogeographic history.” The Amazon rainforest is one of the toughest regions for paleontological field work. The fossils are only accessible during the dry season. River levels there are low enough to expose ancient fossil-bearing rocks. If these fossils are not collected in time, the rains wash them away.
huge skull
The dolphin was found in 2018, when the study’s lead author was still an undergraduate student. The expedition was led by Peruvian paleontologist Rodolfo Salas-Gismondi. Together they crossed more than 300 kilometers of the Napo River.
Dozens of fossils were discovered and collected. But the biggest surprise waited at the end of the expedition, after almost three weeks of exploration. It was the discovery of the large dolphin skull, permanently deposited in the Museum of Natural History in Lima.
