Last month, a crane operator was digging 110 feet below street level when an unusual rock in both shape and color gave him pause. Brandon Valasik called over his supervisor from the Transbay Transit Center, and in a subsequent whirlwind, nearly every publication in California excitedly reported the find to be a wooly mammoth tooth.
"Almost undoubtedly, it is not a wooly mammoth tooth," explained Peter Roopinaire, the curator of geology at the California Academy of Sciences. The wooly mammoth is by far the most famous of them all, but there were actually 10 mammoth species recognized worldwide, ranging in age from 5,000,000 to 3,700 years old.
The Department of Invertebrate Zoology & Geology received the tooth as a donation shortly after it was discovered, and the largest research division in the world sent it straight to the lab for inspection. After the specimen was cleaned and preserved, Roopinaire compiled a fact sheet in which he named the proper species: The upper left molar discovered by Valasik belonged to a Columbian mammoth. Well-preserved Mammuthus Columbi have also been discovered in the La Brea Tar Pits in Los Angeles, and can be seen at the nearby Page Museum.
"It's still incredibly exciting," Roopinaire was quick to point out.
The smooth-skinned mammoth roamed what we now call San Francisco over 150,000-8,000 years ago. The 5-10 ton mammoth enjoyed a habitat dominated by woodlands drained by several large rivers and myriad creeks. The 12-14 foot tall animal lived amongst rich fauna, including saber-toothed cats, horses, tapirs, wolves, camels, bison, and mastodons.
Teeth were essential to a mammoth's survival, and the molar is estimated to be 40 years old. Mammoths grew six sets of teeth during their lifetime, each one eventually wearing down until the animal was reduced to gumming at food before an inevitable death by starvation.
The Academy's collections span the globe, but it was founded on Gold Rush money, and it embraces the opportunity to explore the past on a local level. "Its interesting and important because it adds more to our reconstruction of San Francisco at the end of the Ice Age, when humans were just beginning to colonize," Roopinaire said.
The recent acquisition is the fourth mammoth tooth discovered in a city that developed in a mad dash during the Gold Rush, and then again for reconstruction after the 1906 earthquake and fire. New building in the Bay Area means far more than change from the ground up: It offers the rare opportunity to probe sediment for fossils, and the city requires that experts be on hand to identify potential finds. All four of the mammoth teeth are slated to be carbon dated soon, and the exhibitions team is already hard at work building a comprehensive picture of mammoths in San Francisco, a show we can all look forward to by the end of the year.
The California Academy of Sciences is open seven days a week at 55 Music Concourse (at MLK, in Golden Gate Park), S.F.