Scientists Sift Through 'Bone Bed' to Date Fossils

Sharktooth Hill Bone Bed, a famous part of California's ancient coastline, may have formed over 700,000 years instead of during the mass catatrosphe scientists previously have hypothesized, according to UC Berkeley researchers.

The study indicates the area-which contains 20 to 30 different kinds of shark fossils and some fossils of land animals-is still of interest to researchers and holds a key to California's ancient past, said Jere Lipps, an integrative biology professor and faculty curator of the museum of paleontology.

"There's never been a real study. This is the first real study of it," said Lipps, who has been visiting the area since he was little. "I saw it as opportunity to decipher this problem."

Since the 50-mile-wide bed of shark teeth, whale bones and ancient sea lions was discovered in the 1850s, scientists have developed many hypotheses on how the bones accumulated there, one being that a major natural disaster wiped out these organisms 15 million years ago, Lipps said.

But after analyzing fossils retrieved at the site, Lipps, along with doctorate students, determined that the mass collection of fossils gathered naturally.

Nick Pyenson, a former UC Berkeley graduate student who worked on the research, said abrasion on the bones and teeth as well as the absence of volcanic remains did not indicate the ancient area was the site of a major natural disaster that could have led to the death of animal populations.

Knowing that the fossils gathered over a period of time may also provide key insight into how the animals lived, said Pyeson, who is now a post-doctoral fellow at the University of British Columbia.

"Paleontologists are constantly trying to figure out the biases on our view into the past, and it's important to know if our snapshots of ancient diversity are constrained or have been recorded over long periods of time," Pyenson said in an e-mail. "This information can be critical for understanding, say, the structure of ancient ecosystems."

More work must be done at the site so researchers can develop ways to determine precise times when the animals lived there, Lipps said.

"It's not easy but this is one of this things that make this so much fun because its a puzzle," he said.

Solving the mystery behind the fossil bed's formation may help preserve the area by making the site a spot for future scientific research, Lipps said.

The area of the fossil bed is currently up for sale by the family of Robert Ernst, the land's deceased owner, said Stephen Boyle, attorney for the executor of the Ernst estate.

"The land is up for sale but we are doing it through an offering where people bid for it," Boyle said. "The family would love to see some museum or school buy the property but we are not in control of that."

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