SCIENCE IN THE NEWS #2081 - DigestBy StaffThis is Bob Doughty.And this is Sarah Long with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in Science. Today, we tell about an ancient creature that had feathers. We tell about the deaths of Royal Bengal tigers in a zoo in India. And we tell about remembering events from childhood.
Scientists have re-examined the stone remains of an ancient animal. They say this fossil is not what it was once believed to be. The fossil was found in Nineteen-Sixty-Nine in Kyrgyzstan, a former Soviet republic. The fossil showed a reptile that was twenty-five centimeters long and had four legs. At that time, scientists thought the animal had very long egg- shaped scales on its body. They named it longisquama (long-iss- QUA-mah) which means "long scales." The discovery did not cause much excitement.
But, last year, longisquama was part of a travelling show of Russian fossils. American scientists got a chance to look at it when it was in the midwestern state of Kansas. The scientists study animals that existed millions of years ago. They were led by Terry D. Jones who now teaches at Stephen F. Austin State University in Nacogdoches, Texas.The scientists were very excited when they saw longisquama for the first time. They say it is clear the ancient markings on the stone were made by feathers--not scales. Mr. Jones says longisquama is the oldest fossil of an animal with feathers ever discovered.
The study of the fossil was published last month in the magazine Science. The researchers say longisquama had six to eight pairs of feathers that were very similar to those of modern birds. The report also says the feathers of the ancient animal were designed for flight--not warmth.
However, the report says longisquama did not have the kind of muscles needed to fly under its own power. The scientists say the animal used its wings to float on air currents. And, the study found that the creature had a bony structure similar to modern birds. The structure controls the direction of flight.Mr. Jones and his team were excited about their findings because of the age of longisquama. The fossil was about two-hundred-twenty-million years old. That is seventy-five-million years older than fossils of the earliest known bird.
The scientists say this older feathered animal might be used to dispute a long-held theory. Most scientists believe that birds developed from dinosaurs.
But longisquama has been identified as an archosaur. The archosaurs were reptiles that lived before dinosaurs and birds. If the new findings on longisquama are true, then birds may have developed from it or another feathered archosaur.
However, Mr. Jones and the other researchers do not directly link longisquama to birds. They say they are not sure of the exact relationship between the two. Other scientists argue there is no relationship at all.Mark Norell is a scientist at the American Museum of Natural History in New York City. He has dismissed the findings of Mr. Jones and his team. Mr. Norell says they have not even proven that the fossil shows feathers. He says even if there were feathers on longisquama they would not be in the right place on the body. He says the possible feathers on longisquama connect to the animal's back bone instead of to its ribs or legs. He says this makes it unlikely the animal is related to birds.
Mr. Norell also argues that much more proof would be needed to dispute the long- held theory that birds developed from dinosaurs. He says scientists would have to find many shared qualities between today's birds and several ancient animals.
Mr. Jones agrees that his work does not prove birds developed independently from dinosaurs. But, he says the study does provide enough evidence to support more scientific consideration of such an idea.
((MUSIC BRIDGE))You are listening to the Special English program SCIENCE IN THE NEWS on VOA. This is Bob Doughty with Sarah Long in Washington.
Animal experts in India are investigating the deaths of twelve Royal Bengal tigers at the Nandan-Kanan Zoo in the eastern state of Orissa. Seven of the dead animals were rare white tigers. The zoo is home to the world's largest collection of white tigers.
The Nandan-Kanan Zoo had fifty-six Royal Bengal tigers. The first tiger died on June twenty-third. After the death, doctors gave antibiotic drugs to some of the remaining animals.AT Rao served on the medical team that examined the dead tigers. He says the tigers died from a common infection called trypanosomiasis. It is spread by forest flies.
Mr. Rao says workers at the zoo should have observed health problems in the tigers faster and started treating them sooner.
Some wildlife experts and non-governmental organizations also are blaming zoo officials for the deaths. They say the zoo failed to act in time to prevent the spread of the disease.More than forty-thousand wild tigers lived in India before the country became independent in Nineteen-Forty-Seven. The number of wild tigers has dropped to fewer than four-thousand. Most of the animals now live in nineteen national parks or wildlife areas operated by the government.
Environmental experts say India is losing two-hundred to three-hundred tigers a year to development and to hunters. Trading in wildlife products is banned in India. However, some people continue to kill tigers for their skins, bones and other body parts. Tiger parts are sold in traditional Chinese medicines.One-hundred years ago, about one-hundred-thousand tigers lived in wild areas around the world. Wildlife experts report that fewer than seven-thousand tigers now live in the wild. About half of them are in India. Three kinds of tigers have disappeared completely in the past seventy years. Experts say the remaining tigers live mainly in Southeast Asia and the Indonesian island of Sumatra. Small groups of tigers also live in China, Nepal and Siberia in Russia.
((MUSIC BRIDGE))Many people believe they have a good memory of what happened years ago. However, a new study suggests that adults can not remember events from their childhood.
Research scientists at Northwestern University in Chicago, Illinois studied sixty-seven normal, healthy men. The scientists questioned the men when they were fourteen-years-old and again when they were forty-eight years old. The men answered questions about family relationships,sexuality, religion and general activities.
Results of the study showed major differences between what the men said when they were boys and their memories as adults. The men were likely to have a correct memory of only one subject. The men remembered how much money their fathers earned in relation to their own earning ability.The researchers found that the men did not remember emotional events any better than those that were not emotionally important. They said the only exception was that the men remembered the importance of having a girlfriend.
Daniel Offer of Northwestern noted that late childhood often is said to be the period in life that is most difficult to see clearly. He said the new study shows that this may be true.
The report said the findings may prove important for health care experts who depend on memories to treat patients. It shows that experts need to gather correct historical information about the patient to offer the best treatment. The study was published in the Journal of the American Academy of Child and Adolescent Psychiatry.
This SCIENCE IN THE NEWS program was written by Caty Weaver and George Grow. It was produced by George Grow. This is Bob Doughty.And this is Sarah Long. Join us again next week for more news about science in Special English on the Voice of America.