Chinese archaeologists proposed Wednesday to chronologize the Neogene Period of geology (from 23 million years ago to 2.5 million years ago) in Asia based on a Chinese chronology.

At a three-day workshop that ended Wednesday, archaeologists from Asia, North America and Europe discussed the proposal by Chinese scientists.

Archaeologists chronologize the Neogene by the fossil record of landmark terrestrial mammals, such as elephants and horses, as they evolved rapidly during this geologic period. The problem is that these animals did not evolve at a uniform pace on all continents.

"Both Europe and North America set up their own stable and uniform biochronologies of the Neogene but Asia still did not have a system like this," said Xiaoming Wang, curator of Vertebrate Paleontology with the National History Museum of Los Angeles County, who attended the seminar here sponsored by the Institute of Vertebrate Paleontology and Paleoantropology (IVPP) under the Chinese Academy of Sciences.

"With a vast territory and rich fossils, China will be the only nation in Asia that has the conditions to draft a full biochronology of Neogene in Asia," he said.

Chinese archaeologists have developed a biochronology of the Neogene in China, which was divided into seven ages and 13 units.

"But we have not related this chronology to the findings in neighboring Asian countries," said Deng Tao, an IVPP researcher.

"In Asia, archaeologists developed very different ways to chronologize the Neogene. Some used the European standard, some the North American one. Without an Asian standard, we always referred our chronology to either Europe or North America one for better understanding."

"It is difficult for so many countries and people in Asia to combine but, as one continent, Asia still needs a single standard," said Yukimitsu Tomida, curator of Vertebrate Paleontology with the National Museum of Nature and Science of Japan, also at the seminar.

As an island country and with fewer fossils unearthed, Japan can not develop a Neogene biochronology of its own. An Asian chronology would benefit research in Japan, Tomida said.

"Asian archaeologists have never met together to talk about this before. The Chinese standard can be a starting point. We need to discuss whether this will work or we need other arrangements," he said.

"As high mountains in north and west China emerged, older animal remains were buried under younger ones so the country has quite a complete sequence of settlement in the Neogene. Many places in the world did not have this," said Michael Osgood Woodburne, researcher from the University of Northern Arizona.

"Since China's record is so good, it has strong potential (for developing a chronology of Asia)," he said. "An Asian system will also help the work of researchers in Europe and North America."

But some researchers voiced caution about the proposal. "It remains an open question of a single system," said John C. Barry from Peabody Museum of Harvard University.

He suggested that researchers should be careful about one single system as there was great diversity in Asia. "Putting everything into one system could cause bias."

"We expect to learn from research in neighboring countries so that our chronology will be more complete and stable," said Deng Tao.

(Xinhua News Agency June 11, 2009)