An endangered window into South America's ancient past has gained a new lease on life, thanks to the pioneering efforts of an Argentinean scientist intent on preserving prehistoric animal tracks etched into a remote stretch of coastline that is under threat from rising sea levels, human destruction and developers.
Teresa Manera de Bianco, a palaeontologist and geologist who, with her husband, found the fossilised tracks in 1986 when a winter storm partly blew the sand off a three-kilometre rocky shelf, has raced against time to record the tracks before rising sea levels put them permanently beyond reach. She has also struggled to convince local residents that the tracks, laid down 12,000 years ago when the area was an inland pond teeming with birds and mammals, are worth protecting from destruction.
For her endless curiosity about the animals that produced the tracks and her dedicated quest to preserve them for study by scientists and local people alike, Manera won a Rolex Award for Enterprise in 2004.
A Fossilised Record
A researcher and teacher at the National University of the South in nearby Bahía Blanca, Manera has long lobbied to make the site at Pehuen Co a government-protected reserve. A law protecting the site was finally approved by the provincial legislature in 2005, but it still awaits implementation. "The reserve exists on paper, and now we're fighting to implement the new law," says Manera, who is pressuring the government to speed up the process.
When the law is implemented, the government will provide park guards to protect the site. To date that task has fallen on Manera and her colleagues, along with brigades of university students who have volunteered to act as guards during the summer when the pressure on the site from visitors and vehicles is greatest.
The footprints, produced by at least 22 species of animals, including mastodons, camelids, flamingos and ducks, are especially vulnerable to pressure from vehicles traversing the thin layer of sand that covers the rocky shelf. Although years of public campaigning by Manera have lessened the impact from fishing and visitors to the beach, in recent years more and more people — unaware or unconcerned about the footprints — have been arriving from further afield to fish.
In March 2006, they damaged the biggest prints found to date at Pehuen Co, the 90cm-long and 44cm-wide prints left by the four-metre-high Megatherium, a sloth-like mammal that weighed up to four tonnes.
Race Against Time
While lamenting the damage to the footprints, Manera acknowledges that progress has been made, in part because the Rolex Award helped boost public respect for her work.
"If it weren't for the Rolex Award, there would be nothing left at Pehuen Co," she says. "We wouldn't have done anything. This international recognition came first, and from that came national recognition, which produced the concrete actions we've taken to protect the site. Thanks to Rolex, this attention convinced people in the local community, as well as the official organisations. Without Rolex, we might have just had a small investigation and made a few moulds with help from some science group."
Endangered by Economic Crisis
Manera has used funding from the Rolex Award to make casts of the animal prints, which are being stored and displayed at a museum in Punta Alta. She even perfected an innovative and economical method of making casts from silicon rubber, which provides better-quality moulds than those made from latex or plaster.
Some of Manera's casts — made in the tidal zone during fleeting moments when the seas fall unusually low — are already provoking debate among researchers. For example, she found evidence of hair on the feet of Megatherium, a find that, she believes, settles a lively debate among scientists about whether the animals were hairless.
The most remarkable recent discovery at Pehuen Co was made by one of Manera's students, who found human footprints in the rock in 2005. Manera and her colleagues are now looking for other human prints at the site, with an eye towards understanding how they relate to the animal prints. The human footprints at Pehuen Co are very close in age to those from about 12,500 years ago discovered in Chile — the oldest known human prints in South America.
As she continues to uncover the past, Manera believes that a well-preserved Pehuen Co will provide employment for local residents as guards and interpreters, increasing popular support for the site's preservation. And she also suggests the prints may have something to teach all of humanity about its future. "As we analyse what we've discovered, we ask what happened to these big animals not so long ago. If we can understand what happened to them, perhaps we can prevent some changes that could affect our future. It's a question of the survival of our species."
Published in 2004