In the Amazon region: Zurich researchers discover fossils of the largest prehistoric dolphin

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Researchers from Zurich have discovered a prehistoric species of river dolphin in the Amazon. According to the researchers, it was the largest freshwater dolphin ever found, with an estimated length of about three metres. The extinct species of river dolphin called “Pebanista yacuruna” lived more than 16 million years ago, an international research team led by the University of Zurich (UZH) wrote in an analysis published Wednesday in the journal “Science Advances.” . .

The fossils were found in Rio Napo in the Peruvian Amazon in 2018. Reconstructing its body size from fossils showed that it should have been between 281 and 347 centimeters long, according to the study.

“Such a large body size, also observed in other ancient Amazon inhabitants (e.g. fish and crocodiles), may be due to the high availability of resources in ancient Amazonian ecosystems,” the researchers wrote in the study.

Extinct 10 million years ago

The dolphin became extinct about 10 million years ago, when the previously dominant Pebas swamp system was replaced by the modern Amazon region. The resulting ecological niche was occupied by new whales and relatives of today’s Amazon river dolphins (Inia), which, like modern oceanic dolphins, were pushed out of the oceans by dolphins, UZH wrote in a statement about the study.

But according to the university, it is not just the size of the dolphin that is remarkable. “We expected this fossil found in the Amazon to be a close relative of living Amazon dolphins; instead, Pebanista is related to South Asian river dolphins (genus Platanista),” said lead author Aldo Benites-Palomino.

“The discovery of Pebanista in proto-Amazonian layers provides evidence that Platanista penetrated freshwater ecosystems not only in South Asia but also in South America, even before modern Amazonian dolphins,” the researchers wrote in the study. (SDA)

Source : Blick