Researchers have found the preserved head of an enormous river dolphin, believed to have left the sea and taken shelter in the Amazonian rivers of Peru approximately 16 million years ago. This species, which is now extinct, likely reached lengths of up to 3.5 meters, making it the biggest river dolphin on record.
The recent identification of Pebanista yacuruna, a newly discovered species, brings attention to the urgent peril faced by the world’s remaining river dolphins. According to the primary author of a new study published in Science Advances, Aldo Benites-Palomino, all river dolphins are at risk of extinction within the next 20 to 40 years. The newly discovered species belongs to the Platanistoidea family of dolphins, which were prevalent in oceans between 24 to 16 million years ago.
Surviving river dolphins were “the remnants of what were once greatly diverse marine dolphin groups”, he said, which were thought to have left the oceans to find new food sources in freshwater rivers.
“Rivers serve as a release mechanism for the prehistoric fossil we discovered, as well as for all present-day river dolphins.”
The fossil was found by Benites-Palomino in Peru in 2018 while he was still a university student. He is currently pursuing a doctorate at the University of Zurich’s paleontology department and has stated that the research paper was postponed due to the pandemic.
While accompanying a coworker on a walk, the individual noticed a section of the fossil, specifically a piece of a jaw. Upon realizing what it was and noticing the sockets for the teeth, they exclaimed that it was a dolphin. The discovery was so unexpected that both of them were in disbelief.
“We soon came to the realization that it was not connected to the Amazon river pink dolphin,” he stated. “We discovered an enormous creature whose closest known relative resides 10,000km away in Southeast Asia.”
The discovery was described as interesting by Marcelo R Sánchez-Villagra, who is in charge of the paleontology department at Zurich University. He added that although they had previously uncovered several large species in South America, this is the first dolphin of its species.
According to Benites-Palomino, the fossil was noteworthy for its large size and for lacking any connection to modern river dolphins that inhabit its previous environment.
The conservation of river dolphins, including their closest living relatives in the Ganges and Indus rivers, is a common concern due to the looming threat of extinction. The main contributing factors to their decline, according to the speaker, are urban growth, pollution, and mining. Unfortunately, these issues have already led to the extinction of the Yangtze river dolphin.
Source: theguardian.com
