Scientists Discover Fossilized Skull of Extinct Giant River Dolphin in Peru.
Researchers have uncovered a fossilized skull of an extinct giant river dolphin – a species believed to have migrated from the ocean to inhabit the Amazon River approximately 16 million years ago – in Peru.
Illustration of the river dolphin Pebanista yacuruna. (Photo: J Bran).
Scientifically named Pebanista yacuruna, this river dolphin belongs to the Platanistoidea family, which was commonly found in oceans between 24 and 16 million years ago. The fossil discovery – believed to belong to the largest river dolphin species ever found – was published in the journal Science Advances on March 20.
The Guardian reported that Aldo Benites-Palomino, the lead author of the study, discovered this fossil in Peru in 2018 while he was still an undergraduate student. The research had been delayed due to the COVID-19 pandemic. At that time, he mentioned that he found a piece of jawbone while walking with a colleague.
Upon seeing the fossil, he recognized the dental impressions and realized it was indeed a dolphin. He explained, “Then we realized it was not related to the pink Amazon river dolphin. We found a species that has its closest living relative 10,000 kilometers away in Southeast Asia.”
Benites-Palomino also noted that this fossil is remarkable not only for its size but also because it bears no relation to the river dolphins currently swimming in the waters it once inhabited.
Marcelo R Sánchez-Villagra, director of paleontology at the University of Zurich, concurred with Benites-Palomino’s statement, saying: “After two decades of working in South America, we have found several fossils of giant dolphins in the region, but this is the first fossil of this species.”
Discussing the significance of the research, Benites-Palomino emphasized that the surviving river dolphins today are “remnants of formerly diverse groups of marine dolphins” and are believed to have left the ocean to seek new food sources in freshwater rivers.
This study highlights the potential risks facing all remaining river dolphin species worldwide – species that are currently facing extinction threats in the next 20 to 40 years. Urban development, pollution, and mining are major contributors to the degradation of river dolphin habitats, potentially pushing them to the brink of extinction.
