How a ranger stumbled upon one of the largest fossil finds in California history

While on a routine patrol, Greg Francek came across bone fragments from prehistoric animals that existed millions of years before humans

Imagine a California with volcanoes erupting to the east and Los Angeles buried under the Pacific Ocean. Giant camels, rhinoceros and four-tusked miniature elephants graze on a lush landscape, only to be preyed upon by bone-crushing dogs.

This is the prehistoric scene conjured up by a trove of new fossils discovered in California's Sierra foothills - a hugely significant find, and one of the largest in the state's history.