Workers repairing broken water lines dug up a human skull and some teeth Friday afternoon in a Midway City neighborhood, officials said.
Judy Suchey, a forensic anthropologist from Cal State Fullerton, was called to the site, where she examined the bones and determined that they are human and probably about 500 years old.
The remains were found about 3 feet deep by a crew working about 12:45 p.m. in the 15000 block of Cedarwood Avenue, said Jim Amormino, a spokesperson for the Orange County Sheriff's Department. He said he does not know whether Midway City lies over an archeological site.
By midafternoon, he said, Suchey had also discovered seashells at the site.
Sheriff's deputies said the bones will be taken to a forensic science center in Santa Ana for further research.
After similar discoveries in Irvine in 1997, hundreds of ancient Native American bones were found and dozens of mammal fossils, some estimated to be as old as 12 million years. Those are among several archeological excavations in the last few years across Orange County, where experts say there might be as many as 3,000 sites once home to ancient peoples.