The largest river dolphin fossil has been found — thousands of miles from its nearest living relative, reports an international group of paleontologists in Science Advances.
The team, led by University of Zurich (UZH) paleontologists, located the fossil in the Peruvian Amazon. It measures nearly 12 feet long and dates back about 16 million years. The new freshwater species, named Pebanista yacuruna, is linked to the rare contemporary South Asian river dolphin Platanista and the saltwater relatives from which it likely evolved.
The find was “a big surprise,” says Aldo Benites-Palomino, a UZH paleontologist and an author of the paper. “Fossils of dolphins that lived in river environments are extremely rare worldwide,” Benites-Palomino says. “I do not think anyone in the crew was expecting to find a dolphin on that trip. Fish, yes, crocodiles, yes, but dolphins, no.”
The surprises continued as they examined the fossil. “This is possibly the largest river dolphin ever recorded,” Benites-Palomino says. Also, one would expect the fossil to be related to more contemporary dolphins from the area. But it wasn’t. “Once studied, it became evident that it belongs to the same group of the Ganges river dolphins (Platanistidae), not the Amazon river dolphins (Iniidae).”
