Dolphin May Have ‘Remains of Hind Legs’
By HIROKO TABUCHI, AP
TOKYO (Nov. 5) – 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.
Whale and dolphin fetuses also show signs of hind protrusions but these generally disappear before birth.
Though odd-shaped protrusions have been found near the tails of dolphins and whales captured in the past, researchers say this was the first time one had been found with well-developed, symmetrical fins, Hayashi said.
“I believe the fins may be remains from the time when dolphins’ ancient ancestors lived on land … this is an unprecedented discovery,” Seiji Osumi, an adviser at Tokyo’s Institute of Cetacean Research, said at a news conference televised Sunday.
The full article can be read here.
This is very interesting. You always bring up very interesting news. Thanks!
Humans can grab things with their feet as babies, often have remnants of a tail and swim perfectly fine when infants but have to relearn when older. There are things like that all over biology.
“dolphins and whales were four-footed land animals about 50 million years ago and share the same common ancestor as hippos and deer”
I eat a lot of venison as I hunt. Does this mean hippos, whales and dolphins taste like deer too?
I’m going to need a bigger freezer.
Isn’t this reverse evolution? I’ve been taught that land animals came from the sea. Not the other way around.
I wouldn’t call it “reverse” evolution. Indeed, most likely land animals did evolve from sea creatures but there is nothing against some of these land animals later finding it to their liking to go back to the sea.
maybe not all the animals that came from the water to the land adapted or liked it to weelll on land and thats why they decided to return to the sea and eventually over the millions of years lost their capacity to return to land.
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bye.