Brigid Lynch was working along a wooded creek in a mountainous part of the San Francisco Bay Area when something that didn't look like the rocks she'd been studying caught her eye. It turned out to be the fossilized tooth of a Pacific mastodon.
“I keep joking it wasn’t hard to find,” Lynch, a geomorphologist at Balance Hydrologics, said Friday. “It was just sitting there in the middle of the creek, halfway in, half out of the water.”
