Big Sky Science
__________ PALEONTOLOGY __________
access to a time machine, some people would cruise off to witness
the signing of the Declaration of Independence or maybe the
"It was life's big bang," Stanley says. "Life began an amazing biological frenzy that changed the planet almost overnight. After three-fourths of time on Earth had already passed, life suddenly exploded and nobody knows why. It's one of the biggest mysteries."
Unearthing and unraveling mysteries is what the UM geology professor does. As an invertebrate paleontologist and internationally recognized expert on modern and ancient coral reefs, Stanley uses the fossil record as a window to peer into ancient oceans -- especially since no one has yet invented a machine that will let him go snorkeling in the Triassic.
Why would a tropical reef researcher live in Montana? Stanley says many people don't realize that plate tectonics have rearranged the Earth's face many times. So the fossilized remains of tropical coral reefs are now found high atop the Himalayas of Nepal, the Andes of Peru and the Little Belts of Montana (which were once a tropical seaway). He says Montana's location gives him ready access to many key paleontological sites in western North America.
Reef ecosystems of any time period are important because they act as a barometer for the overall health of life on Earth, Stanley says. Like a canary in a coal mine, they signal when life is robust or in trouble. There have been five big mass extinctions and seven smaller ones during the past 600 million years, and fragile reef ecosystems always have been "the first to fall and last to recover." They seem more sensitive to instability in the environment, and the many hypotheses for these reef catastrophes range from sea-level changes and climate deterioration to meteor impacts or volcanic outgassing. The geologic record shows that after one of these dramatic die-offs, there always is period lasting millions of years in which there are no reefs at all.
And, alarmingly, burgeoning human populations seem to be fueling the next reef die-off. Many coral-damaging microbes can be traced to sewage discharge into the oceans, and new viruses, bacteria and fungi are killing corals at high rates. Experts contend that 10 percent of the worldwide coral cover already is dead and up to another 30 percent is threatened.
Why should we care? Stanley says reefs -- generally made up of aggressive little invertebrates that secrete hard, stony skeletons -- shelter an amazing diversity of life. He says reefs may act as an "evolutionary cradle," birthing new species while nurturing existing life in balmy tropical environments. Reefs indeed may act as a life support system for the entire Earth, serving as an important source of evolutionary innovation.
Coral reef deposits also may shelter humans somewhat from global warming by sequestering large amounts of the carbon from automobiles, factories, burning and similar sources that we inject into the atmosphere. Stanley says coral reefs are immense, taking up large areas of the tropics; and they act as carbon "sinks," pulling megatons of carbon dioxide from the air and incorporating it into the calcium carbonate skeletons of corals. The calcium carbonate in limestone largely results from the remains of corals and reefs, and some theories suggest reefs and limestone accumulations helped control ancient climate.
There are many benefits of corals and reefs. Few people, for example, realize that reefs and the ancient carbonate deposits they produce hold nearly 50 percent of oil and gas reserves. And modern corals are now being harvested for human bone grafts. "Surgeons are implanting corals into human bodies to replace degraded bone because corals are porous and simulate bones so well, so the body will accept them," Stanley says.
Though Stanley is an experienced diver who has visited many of the world's great coral reefs -- he has even taken UM students to explore the barrier reef of Belize -- his true passion is ancient reefs, especially those of the Triassic Period of more than 210 million years ago. He investigates reefs and marine animals found in the remains of ancient volcanic islands that plate tectonics have shifted to far-flung locales -- areas ranging from central Alaska to Sonora, Mexico.
Stanley has helped discover dozens of previously unknown species in the course of his research. In one amazing "Eureka!" moment, he and a UM student found creatures shaped like Mexican hats silhouetted in a wall of black limestone while exploring a quarry in northeastern Oregon. The 3-foot-diameter critters turned out to be a new clam species that lived during the Triassic.
"What is hard for people to understand is the excitement that comes from just cracking open a rock and seeing some new organism, some new fossil, that you realize nobody else knows about," Stanley says. "You understand that you are the only person in the world to grasp this fossil in your hand ... in a deep intellectual way, it's thrilling."
Stanley worked at the Smithsonian Institution before joining the UM faculty in 1982. At Montana he has written and edited six books and published more than 100 scientific papers and writings about paleontology and geology. He recently wrote an article titled "The Origins of Modern Corals" for the prestigious journal Science, and his most recent book, "The History and Sedimentology of Ancient Reef Systems," traces more than a billion years of reef history.
He says one amazing aspect of reefs is they haven't always been dominated by corals. "Before multicellular animals were on the scene, it was bacteria that made the reefs," Stanley says. "It was stromatolites in the Precambrian (more than a billion years ago), which is a bacterial (algal) buildup. If you go back in the fossil record, there have been reefs dominated by sponges and sometimes clams. It's like Shakespeare's 'all the world's a play': We have a mass extinction and the actors change, but the play goes on."
The origin of modern corals has proved to be one of the great mysteries Stanley has encountered in his research. They appeared suddenly in fully developed form in the fossil record about 240 million years ago without any evidence of ancestors. He and his students now are investigating the theory that hard corals evolved from small, soft-bodied sea anemones - animals that resembled corals but didn't have skeletons that could leave a fossil record.
"One of the things I emphasize in my classes is that we have a highly censored fossil record," he says. "We only see things that have shells or hard parts - animals with bone, teeth and the like. The soft-bodied organisms hardly ever get fossilized."
estimates that in some deposits nearly 80 percent of ancient life
was soft-bodied and left no record, creating gaping holes in our knowledge.
But at rare, precious sites - perhaps 20 discovered around the globe
- soft-bodied creatures have been preserved by some geological quirk,
maintaining a vivid snapshot of what life was really like. The most
famous of these are the Burgess Shale in British Columbia and the
newly discovered Chengjiang Biota of southwestern China.
Stanley reviewed an article written by Chinese paleontologists in Yunnan, and they were so impressed by his comments that Professor XianGuang Hou, the discoverer of the Chengjiang Biota, invited him to the Chinese dig last summer. For Stanley the paleontologist, it was like being asked to take a trip back in time.
"It's a four- or five-hour drive from Yunnan University to the site over some of the worst roads imaginable," Stanley says. "They have armies of peasants who sit out there all day and crack rocks. They just keeping cracking out these new forms of life that are totally unexpected."
Stanley was given full access to the site, and he held in his hand a tiny fish fossil that was heralded as a major discovery of the last decade. "It was the ancestor of not only us but every vertebrate," he says reverently. "If this thing had died out, maybe we wouldn't be here. It was a small fish with no jaws, but it had the first backbone and a dorsal tubular nerve cord. Amazing."
Stanley established a good working relationship with his fellow researchers in Yunnan, and he currently is writing a paper about the oldest sea anemones ever found, which were unearthed at Chengjiang. Academic collaboration between UM and Yunnan University is planned; and Stanley will return to Yunnan next June, while Professor Hou intends to visit Missoula in July.
Stanley says fossils are useful because they help reconstruct ancient ecologies and environments. They also can assist with dating rocks and mineral deposits, because some species die out and are never repeated. In addition, fossils can help reconstruct ancient geography. Ancient coral reef remains, for example, indicate tropical settings, and researchers using them can map how the world looked millions of years ago before plate tectonics swapped everything around.
"I've had graduate students who have done geographic work using fossils to create maps of the ancient world," Stanley says. "I have received a new grant from the National Science Foundation for over $250,000 for three years to reconstruct such maps with students and paleontological colleagues."
When he isn't exploring the world for fossils, Stanley teaches full time in UM's geology department, holds down an adjunct position with the biology department and manages the University's Paleontology Research Collection, which was established in 1898 and contains more than 100,000 specimens that represent the ancient heritage of Montana.
As a specialist on ancient reefs and their creatures, Stanley sometimes gets impatient with people who hear he is a paleontologist and automatically assume he studies dinosaurs.
"Most people are never exposed to the broad level of paleontology," he says. "They are at the kid level with dinosaurs and big monsters, but dinosaurs are just one twig on the tree of life. Paleontology actually deals with all life and how broad it can get."
-BY CARY SHIMEK