Thread: Look What They Found In Antarctica!

It's just a tiny fossil of a fly that scientists found some 300 miles from the South Pole. But this fossil will help them:

--figure out what life was like millions of years ago in ancient Antarctica

--help explain global changes in today's climate.


One of the biggest surprises of the discovery:

No one even knew there were flies in this frozen land where summer temperatures are a bone-chilling 20 degrees below zero. The fly fossil is from the Cyclorrhapha family, the so-called "higher flies" that include the common housefly, reports CNN.

North Dakota State University geologist Allan Ashworth, who found the fossil and is recognized as a pioneer in using insect fossils to research climate changes, speculates that flies could have existed during a short-lived warm spell in Antarctica several million years ago. They could also have been part of the animal life on a mega-continent called Gondwana that later split up and formed Antarctica, South America, India, Australia, New Zealand, and Africa. Finding such fossils is "painstaking stuff," Ashworth admitted. But the payoff can be huge because so much can be learned from them. CNN reports that the fossil Ashworth found in Antarctica is 5 to 7.5 millimeters long. The fly is actually in the puparium stage, which is similar to the butterfly's cocoon state--a transition period between the larva and adult insect.


So now the big question to be pondered:

If a warm spell in Antarctica allowed the fly to live there, what caused the temperatures to rise? Some 15 million years ago, it was not greenhouse gases to blame. So what was it? This ancient clue could help scientists learn more about global warming now. The findings were published in the British journal Nature.



Ages of the Earth:

Check out this cool interactive presentation!
http://www.cnn.com/interactive/natur.../frameset.html

Did birds evolve from dinosaurs?

Scientists have found fossilized remains of a dinosaur with four feathered wings, a find that strengthens that theory.

http://www.cnn.com/2003/TECH/science...ged/index.html

While they don't provide immediate answers, the fossils add diversity to the story of flight, scientists say.


(CNN) -- Scientists in China say they have found fossilized remains of a dinosaur with four feathered wings that it probably used for gliding, a find they say strengthens the theory that birds evolved from dinosaurs.

The dinosaur, of the type known as a Microraptor, was about a yard long and lived about 130 million years ago, said the scientists with the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing.

It probably "flew" much as a flying squirrel does, gliding short distances from place to place, and was probably not capable of actual flight, they said.


Nothing resembles it

"It's a phenomenal find," Luis Chiappe, a paleontologist at the Natural History Museum of Los Angeles County, told The Associated Press. "We don't have anything that resembles this in the whole dinosaur and bird spectrum."

The study's authors say their new finds are further confirmation that birds evolved from dinosaurs, a proposal that gained strength in the past century based on the dozens of anatomical features shared by birds and the type of dinosaurs known as theropods. Microraptors are members of that group.

Six fossilized specimens of the creature were found in the Chaoyang Basin in Liaoning, China, in 2001 and 2002, the scientists said. The leg feathers of the fossils are reportedly arranged in a pattern similar to wing feathers in modern birds.

"I never expected to see fly feathers attached to the feet. This is most unusual," lead researcher Xing Xu told CNN. "Finding flight feathers on a non-bird dinosaur is big news."


Fuel for debate

The fossils are likely to reawaken a debate between two theories of how dinosaurs might have evolved into birds. One theory holds that birds' ancient relatives started flapping their wings to fly while gliding. Another theory maintains that the ancient creatures increased their running speed with their wings, eventually taking off from the ground.

A description of the fossils is published in this week's edition of the journal Nature.

In 1999, Xu was part of a scientific team that announced the discovery of fossils dubbed Archaeoraptor lianingensis, purported to offer evidence that many carnivorous dinosaurs sported feathers.

Additional tests were performed, and within months Xu and others concluded that the remains were actually elaborate fakes, composites of difference specimens.

'Looks like things go together'

For this new species of Microraptor, Xu and colleagues conducted extensive tests to ensure they possessed genuine fossils.

"As far as I'm concerned, these are authentic fossils. They've presented extra information to go over that hurdle," said Richard Prum, a University of Kansas bird evolution expert and author of a companion piece in Nature.

Richard Ketchum, a University of Texas research scientist who helped coordinate the Computerized Tomography (CT) scans that determined Archaeoraptor lianingensis was a fake, liked what he saw in the report about the new dino-bird.

"It's a great specimen. From looking at the photo of the slab and the [CT scan] image, it looks like things go together," he said. "With the other one, you could see that it was fake. Some pieces did not fit together."




CNN's Kate Tobin, Ann Kellan and Richard Stenger contributed to this report.

The fossil of a 100-million-year-old turkey-sized bird found in China is so well preserved scientists can even tell what it ate for its last meal.

http://www.cnn.com/2002/TECH/science...eal/index.html


'Pioneer among plant eaters' found in China

The fossil, between 110 million and 125 million years old, was found in China last year.

By Marsha Walton ~~ CNN Sci-Tech

(CNN) -- A turkey-sized bird that lived more than 100 million years ago is now giving paleontologists some important clues about how animals lived and evolved.

The fossil of this new species, Jeholornis prima, was found last year in the Liaoning area of northeast China. It's not just the bones of this big bird that scientists find revealing, but its diet. The fossil shows in great detail more than 50 seeds in the bird's stomach. This is the first direct evidence of seed eating in a bird, believed to be a new adaptation for birds of the Mesozoic era.

"The bird is approximately the size of a turkey, the whole skeleton is about 75 centimeters (30 inches) long, but with feathers in the tail, it could probably be close to one meter," said Zhonghe Zhou, of the Chinese Academy of Sciences. His findings are described in this week's issue of the British journal Nature.

Scientists found the fossil in an area once covered with volcanoes and tropical lakes, where feathered dinosaurs, primitive birds and other mammals have also been unearthed. Jeholornis is slightly larger than Archaeopteryx, the earliest known bird that lived 145 million years ago.

The Cretaceous period, the third and last period of the Mesozoic era, is known for the development of flowering plants, and the disappearance of the dinosaurs.

Powerful flight

Scientists said the skeletal structure shows that this bird was capable of powerful flight, but was also built to sit in trees. Those discoveries provide a further relationship between birds and some theropods, the carnivorous dinosaurs of the Jurassic and Cretaceous periods that walked on two legs and had small, grasping forelimbs.


Although the seeds haven't been identified specifically, they give researchers a better insight to ancient birds' diets.

Because the seeds found in the stomach were intact, researchers say the birds may have eaten them whole, rather than breaking them up into smaller pieces. The seeds would have been "stored" in a crop, or pouch-like area, to be digested later in the gizzard.

"The other birds we know of at this time were probably meat eaters, fish, or insect eaters, based on their teeth," said Thomas Holtz Jr., a paleobiologist at the University of Maryland.

"This guy was sort of a pioneer, giving us the oldest evidence so far that birds ate plants," said Holtz.

Dinosaur link?

Each seed was about a centimeter long. While the seeds are similar in size to the gingko plant, common in that region of China, there is not enough evidence to determine what plant the seeds came from.


Jeholornis was also different from other birds of the period because of a very long tail. Paleontologists say this skeletal tail provides evidence linking birds with dromaeosaurids, dinosaurs that were small, fast, bipedal, and closely related to birds.

"This fossil really increases our understanding of the diversity of early birds," said Holtz. And the region in China where it was found is considered a treasure chest for fossils.

"It gives us an excellent picture of ecology, not only of birds and other dinosaurs, but also mammals, lizards, plants, and potentially insects," said Holtz.