Geologist digs up secrets of evolution's 'big bang'


By ROB CHANEY of the Missoulian

Sea anemones survive by waiting for the world to come to them. A few found by University of Montana geologist George Stanley may have waited almost half a billion years to rewrite the history of survival.

Stanley uncovered fossils of the plantlike tidepool creatures in the Chengjaing Biota, one of a handful of sites in the world that are rocking the science of ancient life. Their discovery is making waves on several levels, from the origins of vertebrate life to the evolution of Chinese museum policy.
"The exciting thing about the fossils we found in China is that these anemones are part of the whole explosion of life in the Cambrian Era - evolution's big bang," Stanley said in a phone interview from Florida on Tuesday. "Multi-cellular life just filled up the sea very suddenly. We don't have much insight into that except the Burgess Shale (fossil deposits), in British Columbia. That site has now been superceded by the most important fossil deposit in the world at Chengjiang."

Most people envision fossils as bones or plants - remains durable enough to turn to stone before they rot. Soft-tissues like skin, organs and sea anemones are "essentially censored" from the fossil record, Stanley said, because they don't last long enough to leave a mineralized impression in the surrounding earth.

The Chengjaing Biota fossil deposit in Yunnan Province is unique in that it's preserved whole remains of soft-tissue creatures such as jellyfish, comb jellies and anemones, with their tentacles, mouth parts and nerve cords, dating back about 525 million years ago. The deposit may also have evidence of the first fish with a backbone - the ancestor of all vertebrate lifeforms.

Stanley specializes in ancient corals and soft-bodied fish. He said finding the anemones furthers a hypothesis of his that they are the early version of modern coral reef colonies. Corals have remained basically unchanged since they appeared in the fossil record about 230 million years ago. But where they came from has been up for debate.

In addition to shedding light on coral origins, Stanley said the Chengjiang deposits are one of the best looks at the vast array of lifeforms that populated the ancient seas.

"People tend to go to the dinosaurs, but I don't study the dinosaurs," Stanley said. "When I show them the chart of the tree of life, one small side branch is reptiles, and a small part of that is the dinosaurs. But look down here at the bottom where life begins - that's pretty exciting."

So exciting that the Chinese government has reversed decades of scientific isolation and invited outside researchers to help study its fossil resources. Stanley has been part of a team of UM and University of Yunnan paleobiologists looking at the Chengjiang deposits. Their discoveries have been prominent enough that the government intervened in the expansion of a nearby phosphate mine that was threatening to overrun the site.

Problems remain with the control of fossil finds. Stanley said he frequently saw Chinese villagers selling fossil remains in local markets, including mashed-up combinations of different creatures passed off as bizarre discoveries.

To combat that, there are strict controls on the removal of fossils from China. That has hindered some of the UM research. For example, UM geochemist Nancy Hinman has been trying to discover the secrets of the Chengjiang mineral mixture that would explain why it recorded such fine details of ancient creatures. But she has had great difficulty having samples sent back to Missoula and plans to make a trip of her own to China soon.

On the other hand, it has spurred the government to develop multimillion-dollar museum and research facilities in Yunnan Province, Stanley said. UM professors are also helping train Chinese researchers so they can develop their own doctorate-level university programs.

"It's a huge country, and Westerners were blocked from doing research there for so many years," Stanley said. "I consider myself fortunate to be involved."