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FreeRepublic , LLC PO BOX 9771 FRESNO, CA 93794
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Posted on 01/22/2003 11:38:37 AM PST by Dallas
Fossil hunters in China have discovered what may be one of the weirdest prehistoric species ever seen -- a four-winged dinosaur that apparently glided from tree to tree.
The 128-million-year-old animal -- called Microraptor gui, in honor of Chinese paleontologist Gu Zhiwei -- was about 2 1/2 feet long and had two sets of feathered wings, with one set on its forelimbs and the other on its hind legs.
Exactly where the creature fits into the evolution of birds and dinosaurs is not clear. But researchers speculated that it developed around the same time as or even later than the first two-wing, birdlike dinosaur, Archaeopteryx, which is believed to have flown by actually flapping its wings.
Paleontologists were intrigued by the discovery. They have seen gliding dinosaurs before, but never one with feathers. And they have never seen a four-winged dinosaur before.
"It would be a total oddity -- the weirdest creature in the world of dinosaurs and birds," said Luis Chiappe, a paleontologist at the Natural History Museum of Los Angeles County who did not participate in the dig.
Scientists said the fossils -- discovered in the Chinese province of Liaoning, northeast of Beijing, at a site that has yielded several important specimens in recent years -- revive a debate between two theories of how dinosaurs might have evolved into birds.
One theory holds that some of these apparent bird ancestors learned to flap their wings to power flight while they were gliding from tree to tree. The other theory suggests they learned to fly by increasing their running speed with their wings and taking off from the ground.
The latest find tends to support the gliding-in-trees theory.
"It's a phenomenal find," Chiappe said. "We don't have anything that resembles this in the whole dinosaur and bird spectrum."
Details of the fossils appear in Thursday's issue of the journal Nature.
Paleontologist Xing Xu of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences described six fossils with leg feathers arranged in a pattern similar to wing feathers in modern birds.
"They are long and some have asymmetrical vanes like flight feathers," Xu said.
The feathered legs amount to rear wings, Xu said. He speculated they could have represented an intermediate stage of development before the emergence of true flight powered by flapping the wings. Or, the feathered legs could have been an evolutionary dead end, other researchers said.
Scientists believe Microraptor gui probably did not fly by flapping its wings, because of the way the rear legs are set in the hip sockets and because the rear legs probably would have encountered turbulence from flapping front wings. That suggests instead that both sets of wings were used just for gliding, Chiappe said.
Other scientists said the fossils add diversity to the story of flight, even if they do not immediately provide answers.
Ken Dial, head of a biological flight laboratory at the University of Montana, said there is room for both gliding and flapping dinosaurs in evolutionary history.
"Gliding represents a splendid example of convergent evolution," Dial said. "We should not be surprised to unearth gliding dinosaurs as we have numerous living-day examples of gliders in nearly all the vertebrate groups -- reptiles, mammals, birds and even parachuting amphibians."
Last week, Dial reported in the journal Science that the way young birds such as turkeys and quail use their wings suggests ancient birds eventually learned to fly by running and flapping.
Paul Sereno, a University of Chicago paleontologist, said the best way to determine whether Microraptor gui was an intermediate stage in bird evolution or a dead end is to find other dinosaur fossils with feathered legs.
Sereno called the Xu study a landmark paper but added: "Whether this represents an intermediate form that all birds passed through is a question that's going to be hotly debated."
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On the Net: Nature: http://www.nature.com
I bet that was a sight to see.
/Dana (Churchlady) Carvey Mode
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FreeRepublic , LLC PO BOX 9771 FRESNO, CA 93794
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If it's a fossil it's not THAT big. Kewl but not big :)
[This ping list for the evolution -- not creationism -- side of evolution threads, and sometimes for other science topics. To be added (or dropped), let me know via freepmail.]
I suppose that would depend on whether you ever met one face to face.
A flying aardvark, quite a concept. No termite or anthill would be tall enough to escape its ravenous appetite.
I believe you have been confused by the Winged Warrior's crime-fighting costume. He's not a missing link, merely the most fantastic crime fighter the world has ever known.
Tastes like chicken? KFC bargain bucket?
Possibly because they found fossil dinosaur bones.
Either that or someone ran out of Crazy Glue again.
Four-Winged Dinosaurs Found in China, Experts Announce
The new species, Microraptor gui, provides yet more evidence that birds evolved from dinosaurs, and could go a long way to answering a question scientists have puzzled over for close to 100 years: How did a group of ground-dwelling flightless dinosaurs evolve to a feathered animal capable of flying?
Xu Xing, a paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China, and colleagues suggest in the January 23 issue of the journal Nature that the species is an early ancestor of birds that probably used its feathered limbs, along with a long, feather-fringed tail, to glide from tree to tree.
Microraptor gui is a new species of Microraptor, in the Dromaeosaur group—which are closely related to birds. An artist's impression illustrates feathered wings, which researchers believe the dinosaur used to glide from tree to tree, much like flying squirrels do today.
Art by Portia Sloan
Click here for a dynamic map of the Liaoning Province in northeastern China: GO >>
They argue that the animal represents an intermediate stage in the evolution of flight, from gliding much as flying squirrels do today to the active wing flapping of modern birds.
Xu's work has long been supported by the National Geographic Society's Committee for Research and Exploration.
The six specimens were excavated from the rich fossil beds of Liaoning Province in northeastern China. They are dated at between 128 to 124 million years old (Early Cretaceous).
"To have fully formed flight feathers on the hind legs is fascinating," said James Clark, Ronald Weintraub Associate Professor of Biology at George Washington University, Washington, D.C.
"There were some interesting speculations about 90 years ago that birds might have had four feathered limbs, but no one has suggested it in recent times, since all living birds use only their forelimbs," he said. "This find broadens the whole scope of thinking about the origins of flight."
The Bird-Dinosaur Connection
Much fossil evidence has been uncovered supporting the idea that birds evolved from a group of bipedal carnivorous dinosaurs called theropods. Within the theropod group, birds are most closely related to dromaeosaurids. Velociraptor, a star in the movie Jurassic Park, is probably the most famous of dromaeosaurs.
Earlier finds in Liaoning suggest that the earliest dromaeosaurs were small, feathered animals with forelimbs similar to those of Archaeopteryx, the oldest known bird at around 150 million years old, and feet with features comparable to modern tree-living birds.
"This species provides another link in the emerging transition from small, meat-eating dinosaurs to birds," said Hans-Dieter Sues, curator of vertebrate paleontology and associate director for science and collections at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania. "These fossils fill in a blank in the fossil record."
Although the M. gui fossils are about 25 million years younger than Archaeopteryx, the four-winged dinosaur is a more primitive form derived from a very early evolutionary branch of dromaeosaurs. The Chinese scientists suggest that the four-winged dinosaur is the most recent known common relative shared by both birds and dinosaurs.
From the Ground or the Trees
M. gui, which is about three feet (1 meter) long, provides evidence that the evolutionary transition to birds included an intermediate phase when there were flight feathers on the hind limbs. The existence of such a stage in the evolution of birds was long ago postulated by naturalist William Beebe in 1915, and by the Danish ornithologist Gerhard Heilmann in 1927. Whether that means they could glide, or even that they were tree-dwellers, remains open to debate.
There are two competing hypotheses that attempt to explain the origin of flight: "ground up" and "tree down."
"Ground up" proponents argue that ground-dwelling dinosaurs achieved flight by developing legs designed for speed and rudimentary wings that when vigorously flapped could either increase velocity or give enough lift to enable the dinosaurs to launch themselves into the air.
The "tree down" hypothesis suggests that birds' most recent ancestors were tree-dwelling creatures that took advantage of gravity and learned to glide before flapping their wings for fully powered flight.
"The argument over whether birds evolved the ability to fly from trees or from the ground is oversimplified and there's no way you can test it," said Clark.
It's just as likely that there was an evolutionary intermediate phase before the gliding phase that got the dinosaurs off the ground and into the trees, he said.
Xu and colleagues support the tree-down hypothesis, arguing that the four-winged dinosaur was built for gliding and the long feathers on M. gui's feet would be a hindrance to running.
"This time the evidence is overwhelming," Xu said. "It's hard even to imagine how these little animals could have moved around bipedally."
Other paleontologists urge caution in interpreting the fossil evidence.
"Xu and colleagues argue that before you could get to flight you had to go through a gliding phase," said Clark. "And intuitively it makes sense that it would be simpler for flight to evolve for a gliding creature than it would be for a ground-dwelling animal.
"That's certainly a possibility, and very plausible, but interpreting function from a fossil is highly speculative," he said. "There's just a lot we aren't going to know."
Mark Norell, chairman of the division of paleontology at the American Museum of Natural History, concurs. "I think you have to be really cautious about inferring biomechanical properties from fossils. However, what these fossils do tell us is that there are some really strange creatures out there, unlike anything around today.
"This shows that people really have to change their conceptions of what dinosaurs are all about," he said. "They're incredibly varied, incredibly diverse, and include everything from small feathered creatures to the large dinosaurs people are most familiar with."
Although the M. gui fossils are about 25 million years younger than Archaeopteryx, the four-winged dinosaur is a more primitive form derived from a very early evolutionary branch of dromaeosaurs.In the creationist strawman version of evolution, of course, more primitive forms are obligated to disappear all over the earth the moment a more advanced form appears anywhere. The constant failure of this to happen is urged as an argument that evolution has not occurred. The same logic means we should no longer have bacteria, fish, or amphibians, but never mind!
There is no reason to suppose that this thing couldn't truly fly, but only glided from tree to tree.
True, the large feathered rear legs could interfere with the flapping front wings, but there is nothing to say that the 4-winged wonder couldn't fold its rear wings straight back, thus giving no serious resistance to flight.
A combination of flying and superior gliding ability would be a good thing.
Where does this leave the Archaeopteryx? This fossil is in these two statement both more primitive and more recent. But what is 25+ million years among friends? Well maybe this just shows that gliding is worth at least 25+ million years.
'Piltdown' bird fake explained
Source: BBC News Published: Thursday, 29 March, 2001, 14:10 GMT 15:10 UK Author: BBC News Online's Helen Briggs Posted on 03/29/2001 17:51:07 PST by LoyalCatholic
Forensic analysis of a forged fossil once hailed as a "missing link" between birds and dinosaurs has shed light on its murky origins.
Sadly, parts of at least two significant new specimens were combined in favour of the higher commercial value of the forgery, and both were nearly lost to science
Scientists believe that the fake is a mosaic built from at least two, and possibly five, separate specimens.
Two significant fossils were almost lost to science while building the hoax, says an international team from the United States, Canada and China.
The specimen, known as Archaeoraptor, captured the attention of the scientific world when unveiled by the National Geographic Society, US, in October 1999.
It reportedly came from a site in China's Liaoning Province that has yielded a host of exquisitely preserved early birds.
With its mix of dinosaur and bird-like features, many palaeontologists believed that Archaeoraptor captured the moment in evolution when dinosaurs were experimenting with flight.
But it later emerged that the tail had been glued on to increase the fossil's commercial value before being sold to a dealer.
The tail turned out to be from a new type of bird-like feathered dinosaur - Microraptor - the smallest, adult dinosaur yet discovered.
Computed Tomography (CT), a technique more common in medical examination, was used to investigate how the forgery was put together.
The analysis was carried out at the University of Texas at Austin, US, in collaboration with experts in China and Canada.
The results suggest that the fossil was built from the front part of the skeleton of an ancient bird, the first of its kind ever seen, cemented on to a slab.
What appear to be random bone fragments of unrelated fossils were stuck on to "complete" the skeleton, making a mosaic that fooled the scientific world.
Dr Timothy Rowe, of the University of Texas at Austin, told BBC News Online: "Now that we know which pieces really do go back together properly and which do not, we can see that there is a new species of extinct bird present in the forgery and that it definitely deserves to be studied and described.
"The tail came from a different animal altogether, and it has already been described and named Microraptor. We may never know where the legs came from."
The Chinese fossil is one in a series of fakes that have fooled paleontologists in the past.
Piltdown man was exposed 40 years after its discovery and recently a dinosaur at the Museum of Wales was shown to be a Victorian hoax.
New forensic techniques, such as those carried out by the Texas team, are increasingly being used to check the authenticity of fossils, said Dr Rowe.
"I would think that insurance companies, auction houses, customs agents, the US Internal Revenue Service, private collectors of fossils, and others with financial stakes in objects like fossils will be concerned and interested in having forensic verification of any specimens that they buy/sell or insure," he told the BBC.
http://www.freerepublic.com/forum/a3ac3e68b6ebc.htm
Yes. A sigh is much better than a senseless flame war. Sometimes you just have to accept that some folks aren't very good at this stuff.
There is a big difference between establishing a lineage and guessing. There is no evidence that the 4 winged bird existed prior to the Archie except by a guess. The feathers on the fan-dancer are flight feathers and are not more primitive than the Archie's. So now we have different fossils found only after the Archie that
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