Unveiling the Ancient Amazon: Discovery of the Largest Freshwater Dolphin

Scientists have unearthed a fossil of an ancient freshwater dolphin, with the discovery dating back 16 million years. The fossil was found in the Amazon's Peruvian region. River dolphins, known for their scarcity, are critically endangered species today.

The finding, reported in the prestigious journal "Science Advances", reveals a dolphin from the Peruvian Amazon which measured between approximately 3 and 3.5 metres in length. This river-dwelling dolphin existed around 16 million years ago.

River dolphins, part of the cetacean order, are among the rarest and are critically endangered. Notably, the closest living relatives to this prehistoric dolphin found in the Amazon are the river dolphins from South Asia. Despite their geographical separation, these groups serve as a testament to the once widespread diversity of cetaceans across the globe.

A group from the University of Zurich in Switzerland has introduced us to the largest river dolphin species discovered thus far, named Pebanista yacuruna in homage to the mythological water dwellers of the Amazon lore.

This dolphin belonged to the Platanistoidea family, widespread across the oceans from 24 to 16 million years ago. The researchers believe that although the species descended from oceanic ancestors, it adapted to a freshwater habitat.

The difficulty of conducting paleontological research in the Amazon is highlighted by researchers. Fossil retrieval is feasible only during the dry season when river waters recede to expose the rocks that contain these ancient specimens. If not recovered before the onset of the rainy season, the rising waters can wash these treasures away, erasing them from history.