SANTA CRUZ ISLAND, Calif. —  Earlier this month, a graduate student photographed what some thought was a remarkable find: A complete tusk of a prehistoric pygmy mammoth.

Fortunately, it didn't turn out to be a mammoth _ it was something even far older.

A team of researchers spent two days on Santa Cruz Island excavating and determined it was a jawbone from an extinct whale species.

Lotus Vermeer of the Nature Conservancy says the bone was found in a rock formation estimated to be between 9.5 million to 25 million years old _ long before mammoths roamed the Channel Islands.

The team dug out the bone and cast it in plaster. The bone, about 3 feet in length, then was airlifted out via a helicopter.

A number of other bones were found nearby that could be even older and may include an intact whale skull.

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