** HOLD FOR RELEASE UNTIL 3:01 A.M. EDT TUESDAY. THIS PHOTO MAY NOT BE PUBLISHED, BROADCAST OR POSTED ONLINE BEFORE 3:01 A.M. EDT TUESDAY ** Rick Greenwood, director of Corporate Environment, Health ... more 
** HOLD FOR RELEASE UNTIL 3:01 A.M. EDT TUESDAY. THIS PHOTO MAY NOT BE PUBLISHED, BROADCAST OR POSTED ONLINE BEFORE 3:01 A.M. EDT TUESDAY ** Rick Greenwood, director of Corporate Environment, Health and Safety for Southern California Edison, poses with the fossilized leg bones of a precursor to the modern horse, in Riverside, Calif., Monday, Sept. 20, 2010. Utility workers preparing to build a new substation in an arid canyon southeast of Los Angeles stumbled on a trove of animal fossils dating back 1.4 million years that researchers say will fill in blanks in Southern California's history. less 
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Associated Press | Photo By Reed Saxon
Tue, Sep 21, 2010 1:37 AM EDT