Smithsonian Museum Discovers New Extinct Species of River Dolphin from Fossil Collection
There are more than 40 million specimens in the Department of Paleobiology in Smithsonian's National Museum of Natural History. A lot of these fossils are interesting, but "a beautiful skull from Alaska," which may belong to a newly discovered extinct dolphin species.
Nicholas D. Pyenson, the museum's curator of fossil marine mammals, and Alexandra Boersma, a researcher in his lab said the fossil is a partial skull that's about nine inches long.
It was found by Donald J. Miller, a geologist from the United States Geological Survey, in south-eastern Alaska in 1951. The skull belonged to a dolphin that swam in the subarctic waters around 25 million years ago.
This dolphin represents a new genus and species called Arktocara yakataga, coined by Pyenson and Boersma themselves.
According to the press release exclusively sent to Nature World News, A.yakataga is a relative of the South Asian river dolphin Platantista. Boersma was able to conclude it by studying the skull and comparing it to both living and extinct dolphins.
The Platantista is the only existing species of a once large and diverse group of dolphins. The skull that was found in Alaska is said to be the oldest fossil ever discovered from the group Platanistoidea. It also proves that Platantista belongs to one of the oldest lineages of toothed whales alive today.
The South Asian river dolphins is very interesting because on how they swim and navigate gloomy or murky waters. South Asian river dolphins cannot see, can only swim on its side, use echolocation for navigation and live only in fresh waters. The Ganges river dolphin and the Indus river dolphin are also part of these species, according to Smithsonian Newsdesk.
"Considering the only living dolphin in this group is restricted to freshwater systems in Southeast Asia, to find a relative that was all the way up in Alaska 25 million years ago was kind of mind-boggling," Boersma said.
Unfortunately, these dolphins are endangered, so studying about them is difficult. Disturbance of it habitat, use of fishing nets and pollution have destroyed the species, with only a few thousand remaining individuals
The researchers reported their findings on Aug. 16 in the journal Peer J. Also, they produced a digital three-dimensional model of the fossil that can be explored at Smithsonian X 3D Beta.