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We're at COP28 to Save the Whale, Save the World.

We’re at COP28 to save the whale, save the world

Ed Goodall Ed is WDC's head of intergovernmental engagement. He meets with world leaders to...
Gray whales from drone.

We’re taking steps to uncover the mysteries of whales

Vicki James Vicki is WDC's protected areas coordinator, she helps to create safe ocean spaces...
We must protect our non-human allies. Image: Tom Brakefield, aurore murguet, johan63

We’re urging governments to protect all of our climate heroes – CITES

Katie Hunter Katie supports WDC's engagement in intergovernmental conversations and is working to end captivity...
The Natütama Foundation are dedicated to protecting endangered river dolphins. Image: Natutama

Guardians of the Amazon: protecting the endangered river dolphins

Ali Wood Ali is WDC's education projects coordinator. She is the editor of Splash! and KIDZONE,...
Amazon river dolphins. Image: Fernando Trujillo/Fundacion Omacha

Amazon tragedy as endangered river dolphins die in hot water

Ali Wood Ali is WDC's education projects coordinator. She is the editor of Splash! and KIDZONE,...
Indo-Pacific bottlenose dolphin © Mike Bossley/WDC

WDC in Japan – Part 3: Restoring freedom to dolphins in South Korea

Katrin Matthes Katrin is WDC's communications and campaigns officer for policy & communication in Germany...
Wintery scene in Iceland

Seeking sanctuary – Iceland’s complex relationship with whales

Hayley Flanagan Hayley is WDC's engagement officer, specialising in creating brilliant content for our website...
Whaling ship Hvalur 8 arrives at the whaling station with two fin whales

A summer of hope and heartbreak for whales in Icelandic waters

Luke McMillan Luke is WDC's Head of hunting and captivity. Now that the 2023 whaling season...

New ancient river dolphin species discovered

Scientists have discovered a new genus and species of river dolphin that has long been extinct. They have named it Isthminia panamensis in recognition of where it was found and believe it is the closest relative of the Amazon River dolphin (boto). Scientists made their discovery in ancient marine rocks of Panama, Central America. These incredible fossils shed new light on the evolution of today’s freshwater river dolphin species.

Isthminia panamensis

Researchers believe that river dolphins’ ancestors were marine dolphins which invaded fresh water river systems as is the case for other fresh water species such as turtles, manatees and sting rays. But until now, the fossil record of river dolphins in this basin has not revealed much about their marine ancestry. This fossil find now gives us a clear boundary in geologic time for understanding when marine dolphins invaded Amazonia.

Group of Amazon River dolphins swimming together

Isthminia panamensis is the closest relative of the living Amazon River dolphin. It is a marine dolphin with a typical river dolphin body plan – that includes broad, paddle-like flippers, flexible necks and heads with particularly long, narrow snouts—all evolved to navigate and hunt in silty rivers and the flooded forest.

Scientists estimate that the ancient dolphins were about 2.84m (9.4 feet) long, which is a little larger than the average boto which lives in the Amazon and Orinoco River Basins of South America.

All living river dolphin species are particularly vulnerable to threats from human activities as they share their fresh water homes and live side by side with human communities.  Botos are illegally hunted for fish bait in the Amazon which is threatening their future survival.

Find our more about river dolphins and more facts about dolphins.

IllustrationLife reconstruction of Isthminia panamensis, feeding on a flatfish, which would have been abundant in the neritic zone of the late Miocene equatorial seas of Panama. Art by Julia Molnar.

Photo of river dolphins: Fernando Trujillo/Fundacion Omacha

Full scientific paperPyenson ND, Vélez-Juarbe J, Gutstein CS, Little H, Vigil D, O’Dea A. (2015) Isthminia panamensis, a new fossil inioid (Mammalia, Cetacea) from the Chagres Formation of Panama and the evolution of ‘river dolphins’ in the Americas. PeerJ 3:e1227 https://dx.doi.org/10.7717/peerj.1227