Expert Says Platypus Faces Extinction

Fossils found at one of the world’s richest archeological sites have led scientists to fear for the survival of the platypus, a furry mammal with webbed feet, a beaver-like tail and a ducklike bill.

Michael Archer, one of the scientists who discovered the fossil site in northwestern Queensland, believes the platypus may be on the same evolutionary path as the extinct Tasmanian tiger.

“I would be delighted if it survives 1,000 years, but I would be surprised if it lasts 100,” said Archer, professor of zoology at the University of New South Wales.

Archer bases his theory on information gleaned from 25-million-year-old fossils of the platypus’s ancestor, the obdurodon, which were found at Riversleigh, a huge cattle station in the parched savannah below the Gulf of Carpentaria.

“It was a very important find because it was instrumental in telling us that the platypus is in evolutionary trouble,” Archer said.

He explained that the platypus that inhabited the lush tropical forests of Australia millions of years ago had many advantages over its modern descendant. Over time, the platypus has become smaller, less versatile and less able to ward off predators, he said.

“It used to have a huge set of teeth, it was much bigger and inhabited about half the continent,” Archer said.

The numbers that remain are impossible to determine, but the platypus has disappeared from South Australia, where it was common 100 years ago, said Dominic Fanning, a research fellow at Taronga Zoo in Sydney.

“Now the (toothless) platypus only exists on the eastern river systems,” Archer said. “It has become too specialized, less able to adapt to the changing environment.”

Riversleigh, 160 miles northwest of Mt. Isa, an old mining town, has been recognized as one of the world’s richest fossil deposits, yielding perfect bones, teeth, skulls and sometimes entire skeletons of creatures that roamed the continent 25 million years ago.

Since full-scale exploration began at the site in 1983, paleontologists have unearthed at least 200 new fossil species embedded in the hard limestone.

“Riversleigh has given us a unique picture of about 25 million years of Australian life,” Archer said. “It was our first glimpse of paleontological paradise.”

Using explosives, crowbars and sledgehammers, the scientists have uncovered relics of meat-eating kangaroos, tiny koalas, marsupial lions, insects, bats and a giant 25-foot python, which they have named Montypythonoides.

Archer and his colleagues return to the site once a year to dig for fossils.

“Every time we go, we find something new,” he said.

Before 1983 scientists knew of fewer than 70 Australian land mammals older than 2 million years, Archer said.

However, the Riversleigh deposits--the exact locations of which are kept secret to guard against scavengers--have turned up more than 200.

“The fossils are giving us information to enable us to interpret the past and, hopefully, to gauge the future. It is crucial that this body of data be considered when conservation decisions are being made,” Archer said.

Archer still keeps a memento in his study of one potentially earth-shattering discovery, a well-preserved human molar embedded in rock 15 million to 20 million years old.

“The oldest known human fossils are about 4 to 5 million years old, so this was extraordinary,” he said. “We were jumping with excitement.”

This “astounding paleontological discovery,” Archer added, turned out to be an elaborate hoax by one of his colleagues, who had used all his expertise to turn a recently pulled wisdom tooth into a fake fossil.