By RANDOLPH E. SCHMID, AP Science Writer Thu Feb 23, 5:13 PM ET
WASHINGTON - The discovery of a furry, beaver-like animal that lived at the time of dinosaurs has overturned more than a century of scientific thinking about Jurassic mammals.
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The find shows that the ecological role of mammals in the time of dinosaurs was far greater than previously thought, said Zhe-Xi Luo, curator of vertebrate paleontology at Carnegie Museum of Natural History in Pittsburgh.
The animal is the earliest swimming mammal to have been found and was the most primitive mammal to be preserved with fur, which is important to helping keep a constant body temperature, Luo said in a telephone interview.
For over a century, the stereotype of mammals living in that era has been of tiny, shrew-like creatures scurrying about in the underbrush trying to avoid the giant creatures that dominated the planet, Luo commented.
Now, a research team that included Luo has found that 164 million years ago, the newly discovered mammal with a flat, scaly tail like a beaver, vertebra like an otter and teeth like a seal was swimming in lakes and eating fish.
The team, led by Qiang Ji of the Chinese Academy of Geological Sciences in Beijing, discovered the remains in the Inner Mongolia region of China. They report their findings in Friday's issue of the journal Science.
Matthew Carrano, curator of dinosaurs at the Smithsonian's National Museum of Natural History, called the find "a big deal."
An important factor is how specialized the creature was, said Carrano, who was not part of the research group.
"It gives a hint that early mammals were not just these shadowy creatures at the time of dinosaurs" but were having their own evolution. There have been hints of such animals in the past but nothing equal to the remains found by Luo and colleagues, he said.
Thomas Martin of the Research Institute Senckenberg in Frankfurt, Germany, said the discovery pushes back the mammal conquest of the waters by more than 100 million years.
"This exciting fossil is a further jigsaw puzzle piece in a series of recent discoveries," commented Martin, who was not part of Luo's team.
It's the first evidence that some ancient mammals were semi-aquatic, indicating a greater diversification than previously thought, the researchers said.
Modern semi-aquatic mammals such as beavers and otters and aquatic mammals like whales did not appear until between 55 million years ago and 25 million years ago, according to the researchers.
The new animal is not related to modern beavers or otters but has features similar to them. Thus the researchers named it Castorocauda lutrasimilis. Castoro from the Latin for beaver, cauda for tail, lutra for river otter and similis meaning similar.
The researchers found imprints of the fur, both guard hairs and short, dense under fur that would have kept water from the skin.
Weighing in at between 1.1 and 1.7 pounds, about the size of a small female platypus, Castorocauda is also the largest known Jurassic early mammal.
The research was funded by the U.S.
National Science Foundation, National Natural Science Foundation of China, Ministry of Science and Technology of China, Chinese Ministry of Land Resources,
National Geographic Society and Carnegie Museum.
Not an armored Jigglypuff
"I salute your genetic superiority, now Get off my planet!!" -- Adam Stiener, 1st Somerset Strikers
Fascinating...That's quite a revelation. If there existed such semi-aquatic mammals like this, could there be the possibility that there were other large land mammals co-existing with dinosaurs?
Elheru Aran wrote:...curse my recent taste for classic porn... my first thought was a '70s-era classic hair-covered muff!
Don't worry. I'm sure a lot of people on this board would have a...different meaning of 'beaver' when they first see the thread title.
"everytime a person is born the Earth weighs just a little more."--DMJ on StarTrek.com
"You see now you are using your thinking and that is not a good thing!" DMJay on StarTrek.com
"Watching Sarli argue with Vympel, Stas, Schatten and the others is as bizarre as the idea of the 40-year-old Virgin telling Hugh Hefner that Hef knows nothing about pussy, and that he is the expert."--Elfdart
I just try to cope with the fact that those guys thing a 1.5 pount "rat" overthrows the knowledge of mammals in the jurassic period wer only "small rodents", hiding from the dinos.
OK, it is about twice or triple the size of any other mammal of that time, but that doesn't make mammals huge, dino-eating monsters...
What kind of weed do they smoke in China?
A minute's thought suggests that the very idea of this is stupid. A more detailed examination raises the possibility that it might be an answer to the question "how could the Germans win the war after the US gets involved?" - Captain Seafort, in a thread proposing a 1942 'D-Day' in Quiberon Bay
LaCroix wrote:I just try to cope with the fact that those guys thing a 1.5 pount "rat" overthrows the knowledge of mammals in the jurassic period wer only "small rodents", hiding from the dinos.
OK, it is about twice or triple the size of any other mammal of that time, but that doesn't make mammals huge, dino-eating monsters...
They didn't say they were. They're just saying they had a more dynamic role than "Scavenger who got lucky".
What kind of weed do they smoke in China?[/quote]
Soft drugs aren't that much talked about. It's the rave parties that do ecstasy and special K.[/quote]
How naeive am I that the first thing I thought of was cereal?
Not an armored Jigglypuff
"I salute your genetic superiority, now Get off my planet!!" -- Adam Stiener, 1st Somerset Strikers
SAMAS wrote:How naeive am I that the first thing I thought of was cereal?
Your not the only one as I don't believe I've ever heard of a designer drug by the label of Special K.
What is it, if you don't mind my asking?
You shall be the instrument of my vengence. Through you I shall scream out my wrath unto the heavens.
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Church of Perverts: As the Lord commands, so shall we do. And do. And do.
Elheru Aran wrote:...curse my recent taste for classic porn... my first thought was a '70s-era classic hair-covered muff! :oops:
Don't worry. I'm sure a lot of people on this board would have a...different meaning of 'beaver' when they first see the thread title.
Not only that, I originally read "Paleontologists" as "Proctologists."
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"These deadly rays will be your death!"
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