Local mammoth tooth on display
November 14, 2012
Two months ago, crane operator Brandon Valasik unearthed a fossilized tooth 110 feet below street level at the construction site for the new Transbay Transit Center in downtown San Francisco. Later identified as the upper left molar of a Columbian mammoth (Mammuthus columbi), the specimen was donated to the California Academy of Sciences by the Transbay Joint Powers Authority, where it was cleaned, preserved, and added to the research fossil collection. The tooth is now on display in the Naturalist Center alongside other fossils from Ice Age San Francisco, and will be there for several months.
An adult mammoth had four large teeth, two upper and two lower. As these molars wore down and became smaller and broken, new teeth formed behind them. The new teeth gradually pushed out the old ones, moving into the same position in the jaw. The Transbay tooth belonged to a 40-year-old mammoth, and is broken into two pieces, with the front third of the tooth is still missing. The smaller piece may at some point be used for carbon dating to determine when the animal lived.
These vegetarian mammals stood 12-14 feet tall, and lived 150,000 – 8,000 years ago in North American grasslands from Canada to Central America. During the time of the Columbian mammoth, the area around what is now San Francisco was dominated by woodlands that were drained by several large rivers and many creeks. A rich fauna, including saber-toothed cats, horses, wolves, camels, bison and mastodons, as well as mammoths, lived here.