Woolly mammoth tooth found at San Francisco work site SAN FRANCISCO - A woolly mammoth tooth with its enamel still intact has been discovered during excavation for a new transit center in downtown San Francisco. A crane operator came across the 10-inch-long brown, black and beige tooth earlier this week while digging a 200-foot hole for a piling at the Transbay Transit Center. Woolly mammoths, giant elephant-like animals, roamed the Bay Area some 10 million to 15 million years ago in the Pleistocene era. The tooth is broken in two and missing a chunk, but is otherwise in relatively good condition. "It's a significant find," Jim Allen, a paleontologist and geologist for the transit center project, told the San Francisco Chronicle. Other woolly mammoth fossils have been found in the Bay Area, but Allen said the discovery right in the middle of downtown San Francisco as well as the tooth's surprisingly good condition were unusual. The tooth is from the same era as fossils found in the La Brea Tar Pits in the Miracle Mile area of Los Angeles - a paleontological gold mine of Ice Age beasts that were trapped by asphalt bubbling upward through cracks and fissures. More than a million bones have been recovered from the ponds. The tooth appears to be from a Columbian mammoth, a relative of today's elephants, Allen said. Brandon Valasik, the crane operator who made the discovery, told the Chronicle that he was digging through sand about 110 feet down when he noticed what resembled a rock but had an unusual shape and color. "It looked too perfect to be a rock," he said. Valasik stopped digging and called over a boss, who took pictures and sent them to Allen. The transit center construction site has yielded other treasures, including a gold nugget and artifacts from Irish neighborhoods that stood there in the 1800s.