Artistic reconstruction of Pebanista yacuruna. Image: Jaime Bran//Science Advances
Dolphins are, without a doubt, one of the best creatures in the world. They’re playful and fun and cute and yes, they too like to surf. They’ve been around for a while now, living in both salt and fresh water, and researchers uncovered fossil evidence in 2018 that shows there was, at one point, a dolphin swimming around that was absolutely giant.
“Here, we describe Pebanista yacuruna gen. et sp. nov., a dolphin from the Miocene proto-Amazonia of Peru, recovered in phylogenies as the closest relative of Platanista,” the authors of a paper published in Science wrote. “Morphological characters such as an elongated rostrum and large supraorbital crests, along with ecological interpretations, indicate that this odontocete was fully adapted to fresh waters. Pebanista constitutes the largest freshwater odontocete known, with an estimated body length of 3 meters (9.8 feet), highlighting the ample resource availability and biotic diversity in the region, during the Early to Middle Miocene.”
The fossilized skull was much larger than the dolphins of today. Image: Science Advances
It’s likely you’ve seen — probably not with your own eyes — those wild pink dolphins that live in the Amazon and Southern Aika. They’re not doing all that well and are one one of the world’s most threatened species, but it’s likely that that the fossilized giant dolphin is an ancestor.
They lived around 16.5 million years ago, and their fossilized remains were found in Rio Napo, Loreto, Peru. With a thick body, long snout, and tiny little eyes that barely worked, P. yacuruna likely made its way through the waters of the Amazon using primarily echolocation. Researchers, after looking at the skull, think it was probably adapted entirely to living in fresh water. The Ganges river dolphin has the same eyes — that is to say tiny and barely functional.
After the team had a thorough look at the skull they found, they came to the conclusion that P. yacuruna a relative of dolphins like the Ganges river dolphin, which, as you probably suspected from the name, lives in the Ganges river in India, as well as the Amazon river dolphins.
Back when P. yacuruna was still swimming around, the Amazon was a very different place, which likely played a part in its size. “The Amazon would have consisted of vast areas of mega wetland,” wrote IFL Science, “and freshwater environments with an abundance of food and broad diversity of species, leading to its evolution of a greater body size.”
