Scientists Find Fossils Of Rare Dolphin Species That Lived In River

Posted: Sep 1 2015, 9:26pm CDT | by , in News | Latest Science News

 

Scientists find Fossils of Rare Dolphin Species that Lived in River
Artistic view of new dolphin species Smithsonian Institution
 

The new dolphin species, discovered by Smithsonian Institution, can solve the mystery of how dolphins moved from seas to rivers

Scientists discovered a new species of dolphin in the coast of Panama. The fossils of the new species indicate that it lived more than 5.8 million years ago and could be nine feet long.

The scientists are particularly interested in this new species since it is a rare kind of dolphin that lived in the river and is closely linked to river dolphins today. And it can help solve the mystery of how dolphins moved from seas to the river.

There are only four species of river dolphins exist now and all are listed as endangered. The fossils pieces discovered by Smithsonian scientists consist of a half skull, a lower jaw with teeth, right shoulder blade and two small flipper bones.

The structure of extinct dolphin species, paddle like flippers, flexible necks and long snout, suggest that this animal was well-suited for hunting in rivers and had made a transition from oceans to rivers.

Scientists have given it the name Isthminia panamensis, which recognizes both Panama and specimen’s living relative, Amazon river dolphin, Inia geoffrensis. They believe that new species can provide a missing link between river dolphins and their oceanic ancestors. 

“We discovered this fossil in marine rocks, and many of the features of its skull and jaws point to it having been a marine inhabitant, like modern oceanic dolphins,” said Nicholas D. Pyenson, curator of fossil marine mammals at Smithsonian National Museum of Natural History.

“Many other iconic freshwater species in the Amazon, such as manatees, turtles and stingrays have marine ancestors, but until now the fossil record of river dolphins in this basin has not revealed about their marine ancestry. Isthminia now gives us a clear boundary in geologic time for understanding when this lineage invaded Amazonia.”

Aaron O’Dea, scientist at Smithsonian Tropical Institute Research in Panama and co-author of study said.

“Isthminia is actually the closest relative of the living Amazon river dolphin. While whales and dolphins have long ago evolved from terrestrial ancestors to fully marine mammals, river dolphins represent a reverse movement by returning inland to freshwater ecosystems. As such fossil specimens tell story not just of the evolution of these aquatic animals, but also of changing geographies and ecosystems of the past.”

The study was published in PeerJ.

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Hira Bashir covers daily affairs around the world.

 

 

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