It started as just another day for crane operator Brandon Valasik. "I was excavating, going through a layer of sand when suddenly I noticed some strange object that came out."
From 110 feet below the surface, he found the tooth and part of a jaw of a woolly mammoth -- considered the most famous of the prehistoric mammals and a cousin of the modern day elephant.
Paleontologist James Allen calls the fossil a well preserved and significant find. The wooly mammoth lived during what is called the Pleistocene Epoch 1.8 million to 11,000 years ago.
"The Bay Area was a grassy valley with herds of these extinct animals roaming around," said Allen.
Allen believes these fragments could be 10 or 11,000 years old.. "It's a big deal . We can study it, get dome age data which helps us figure out tectonics and seismology like the San Andreas Fault over there."
Throughout this project Transbay officials have had archeologists on the scene, and a treasure trove of other artifacts has been uncovered. The work continues on schedule, but now everyone is on the lookout for another piece of what one observant crane operator scooped up and set aside.
"A few people tried to convince me that it was just a rock, but it looked too perfect to be a rock," said Valasik.
Paleontologists say woolly mammoths were common in the Bay Area during the ice age. A decision has not yet been made regarding what will be done with the tooth, but it may be donated to the California Academy of Sciences in San Francisco, or the Transbay Transit Center may put it on display.