September 14, 2012
Construction Worker Digs Up Mammoth Tooth In San Francisco
April Flowers for redOrbit.com - Your Universe Online
How did your Monday at work go? Mine was pretty much the same as every Monday. Not so for Brandon Valasik in San Francisco, however.Valasik works at the Transbay Transit Center construction site as a crane operator. On Monday, he found a tooth. A woolly mammoth tooth, approximately 10 inches long, broken in two and missing a chunk, to be exact.
The woolly mammoth roamed the grassy valley that is now San Francisco Bay between 10 to 15 thousand years ago, during the Pleistocene epoch. Other woolly mammoth fossils have been found in the area, in at least three other locations. Jim Allen, a paleontologist and geologist working for the project, said the tooth is in remarkable condition with the enamel still intact, and has not deteriorated to the point of most fossils.
"It's a significant find," he told Michael Cabanatuan of the San Francisco Chronicle on Wednesday. "It's unique to find something right smack in downtown San Francisco."
Woolly mammoths are one of the best understood prehistoric vertebrates because, for the most part, their bodies didn't actually fossilize. That is, they didn't turn to stone, but rather are preserved in their organic state, partly because of how large they were and partly because of the frozen habitats they lived in. Mammoths were close in size to the modern day African-elephant, with a thick layer of shaggy hair and an undercoat of fine wool, similar to musk oxen. They had a layer of fat about 8 inches thick, much like whale blubber.
Valasik discovered the tooth while excavating a 200-foot deep hole inside a steel casing for one of the 181 pilings that will form a buttress wall for the massive transit center. Digging through a layer of dark sand about 110 feet underground, he scooped out some soil and dumped it on the ground. That's when he spotted the tooth, thinking it looked like very unusual rock.
"It looked too perfect to be a rock," he told Cabanatuan.
Valasik stopped digging and examined his discovery. He called over a boss who took pictures and sent them to Allen. Later in the day, Valasik said, he was told that what he found once sat in the mouth of a woolly mammoth.
"I've been to Washington, D.C., to the Smithsonian," where he saw a woolly mammoth skeleton, he said, "but I never expected to find part of one."
Co-workers have since taken to calling him "Manny," an animated mammoth in the "Ice Age" movies.
Excavation work in the area was halted for a while, but Allen said because of the depth of the discovery it would be unrealistic and unsafe to send someone down to inspect the site. The crews were allowed to resume digging, but Allen and the construction crews are keeping an eye on the diggings. Transbay officials say they also think they have discovered a jaw.
Allen hasn't had much time to do research on the tooth yet, but he said it appears to be from a Columbian mammoth, a relative to the modern elephant. Woolly mammoths were common in the Bay area during the Ice Age, a time in which there was no bay and the Pacific Ocean was far away. Allen likened the region to Africa today.
"It was a zoo here," he said. "Mammoths, mastodons, short-faced bears, saber-toothed cats, they were all hanging out. ... If you could go back to the Bay Area 10, 15 thousand years ago, it would be a pretty wild scene."
The tooth is from the same age as the specimens in the La Brea Tar Pits in Los Angeles, and will aid scientists in the study of evolution, extinct animals, geology and tectonic forces that cause earthquakes. The tooth will probably be donated to the California Academy of Sciences, though the Transbay Transit Center may put it on display.
Construction crews have made other finds while excavating the foundations for the Transbay Transit Center. A couple of years ago, they unearthed artifacts from working-class Irish neighborhoods that filled the area in the 1800s, along with a small gold nugget.
"We're not only building the future," said Maria Ayerdi-Kaplan, executive director of the Transbay project. "We're preserving the past."