Dolphin May Have 'Remains' of Legs
Researchers Say Dolphin Has 'Remains' of Legs, Possible Evidence Ocean Mammals Lived on Land
By HIROKO TABUCHI
TOKYO Nov 5, 2006 (AP)— Japanese researchers said Sunday that a bottlenose dolphin captured last month has an extra set of fins that could be the remains of hind legs, a discovery that may provide further evidence that ocean-dwelling mammals once lived on land.
Fishermen captured the four-finned dolphin alive off the coast of Wakayama prefecture (state) in western Japan on Oct. 28, and alerted the nearby Taiji Whaling Museum, according to museum director Katsuki Hayashi.
Fossil remains show dolphins and whales were four-footed land animals about 50 million years ago and share the same common ancestor as hippos and deer. Scientists believe they later transitioned to an aquatic lifestyle and their hind limbs disappeared.
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The second set of fins much smaller than the dolphin's front fins are about the size of human hands and protrude from near the tail on the dolphin's underside. The dolphin measures 8.92 feet and is about five years old, according to the museum.
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A freak mutation may have caused the ancient trait to reassert itself, Osumi said. The dolphin will be kept at the Taiji museum to undergo X-ray and DNA tests, according to Hayashi.
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http://abcnews.go.com/Technology/wireStory?id=2629683In this photo released by Taiji Whale Museum, divers hold a bottlenose dolphin which has an extra set of human palm-sized fins near its tail in Taiji, Wakayama prefecture (state) in western Japan, on Saturday November 4, 2006. Japanese researchers said Sunday that the could be the remains of back legs, providing further evidence that ocean-dwelling mammals once lived on land. (AP Photo/Taiji Whale Museum)On editI had always thought that the Dolphin's tail was itself hind legs that had fused together over the eons into a big fin. Could it be that the Dolphin's tail is actually an adapted land-mammal tail, and not two back legs fused into a tail?