CNN:2 articles on Chinese redating of feathered dinosaurs

[Betty Cunningham <bettyc@flyinggoat.com>]

these are both CNN custom news articles. If the URLs don't work for you
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http://customnews.cnn.com/cnews/pna.show_story?p_art_id=3915447&p_section_name=Sci-Tech&p_art_type=652817&p_subcat=Arch.+%26+Paleontology&p_category=Sciences

Scientists Pinpoint Age of Feathered Dinosaur
Xinhua           30-JUN-99

BEIJING (June 30) XINHUA - The age of the so called feathered dinosaur,
Sinosauropteryx, which is deemed the ancestor of modern birds by many
scientists, has been pinpointed at 125 million years old by a team of
international scientists. 

The conclusion followed joint research by Swisher Carl from the
Berkeley  Geochronology Center in the United States and Wang Yuanqing
along with other Chinese scientists from the Institute of Vertebrate
Paleontology and Paleoanthropology under the Chinese Academy of Sciences
(CAS). 

Their paper making this claim will be published in the British science
journal, Nature, tomorrow. 

The research also indicates that the oldest flower and the primitive
mammal, Zhangheotherium, whose fossils were found in the same area with
that of feathered dinosaur, Beipiao in northeast China's Liaoning
Province, lived at the same time, the early Cretaceous Period, instead
of the late Jurassic Period of 144 million years ago as previously
thought, said Xu Xing, one of the authors of the paper. 

The discovery of a large number of important fossils, including
Confuciusornis, Sinosauropteryx, Jeholodens, and the oldest flower, in
the same region in Liaoning Province, has drawn wide attention from
international academic fields. 

However, scientists are divided over the age of the fossils from the
late Jurassic Period to the early Cretaceous Period. Most of the papers
published in academic journals are based on biological stratigraphic
study. 

Chinese scientists collected turf samples from the fossil- bearing
stratum and sent the samples to the famous Berkeley Geochronology Center
in the United States for 40Ar/39Ar dating. 

"This dating method is very accurate," said Xu. He said that the dating
shows that the famous fossils found in Beipiao in Liaoning Province were
younger than previously thought. "We are forced to re-consider the
complexity of biological evolution." 

"Clarifying the exact age of the fossils will provide new insight into
the study of the origin of birds, mammals and flowering plants," he
added. 

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http://customnews.cnn.com/cnews/pna.show_story?p_art_id=3916999&p_section_name=Sci-Tech&p_art_type=652817&p_subcat=Arch.+%26+Paleontology&p_category=Sciences

Feathered Dinosaurs Are Not so Old, Research Shows
Reuters       30-JUN-99

 LONDON (Reuters) - Fossils of feathered dinosaurs and flowering plants,
considered an extremely important discovery when they were unearthed in
the Liaoning province in China, are not as old as scientists had
thought, researchers said Wednesday. 

 The discovery of fossil remains of species with distinctive feathers
and dinosaur features and the world's oldest flowering plant in China
were among the biggest finds in recent years. 

 Scientists had estimated the diverse fauna found in ancient lake beds
in Liaoning province were from the late Jurassic period -- about 140
million years ago. 

 But new dating methods, published in the science journal Nature, of
sediment in which the fossils were found, puts them in the Cretaceous
period, 20 million years later than previous estimates. 

"Probably no other story has created so much attention in the last
couple of years as the feathered dinosaurs or the world's oldest
flowering plant or some other aspect of this fauna from China," Carl
Swisher III, of the Berkeley Geochronology Center in California, said in
a telephone interview. 

"Most people thought it was quite old but these dates directly
associated with the fauna suggest it is not as old as originally
thought." 

Swisher and his colleagues based their dates on measurements taken from
a mineral found in volcanic ash used in dating isotopic age. 

In addition to accurately dating Caudipteryx and Protarchaeopteryx, two
species found in Liaoning that represent a link between dinosaurs and
birds, the research sheds new light on plant and animal evolution. 

Zhexi Luo, of the Carnegie Museum of Natural History in Pittsburgh, said
any new information about the transition between the Late Jurassic and
Early Cretaceous periods, which saw the evolution of feathered
dinosaurs, flowering plants and the diversification of different mammal
groups, is important. 

 "The western Liaoning province and its neighboring areas are a refugium
-- an isolated area in which a population survived much longer than
elsewhere -- for these relict (ancient animal or plant remains) lineages
from a bygone area," he said in a commentary in Nature. 
-- 
Flying Goat Graphics
http://www.flyinggoat.com
(Society of Vertebrate Paleontology member)
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