'EWA BEACH — Authorities were investigating the discovery of half of a human skeleton on the shore at One'ula Beach Park yesterday morning.

Patrick Ortiz of 'Ewa Beach said he was collecting shells along the beach about 8:30 a.m. when he spotted what he thought was a silver dollar-sized seashell protruding from the sand.

"So I started digging it up and found the eye," said Ortiz, 30. "I kept digging and the whole skull came up."

Officials made a preliminary determination that the person died more than 50 years ago, placing the remains in the jurisdiction of state preservation officials and not police.

The skull, with its mouth agape, was a shocking sight in the sand, Ortiz said. At first he said he thought it must be fake. But as he continued removing sand he was further startled to find the bones of a human head, torso and arms.

Ortiz said he immediately reported the find to the police department, and that officers arrived a short time later.

The skeleton was positioned as if reclining on its back looking out of a shallow grave on the beach, Ortiz said. He said one officer knocked on the skull, apparently to determine whether it might be made of plastic or some other material. But once officers realized the bones were real, he said, they cordoned off the area and called in experts from the State Historic Preservation Division to determine the age of the remains.

The preliminary findings of the archeologists at the scene was that the bones were not ancient but that the person they belonged to had been dead for more than half a century, said HPD District 8 Maj. Michael Moses.

"I think they said something about there are some old burial grounds in that area, he said. "So there's a possibility that because of the usage of the park and the natural weathering that the bones became unearthed."

Moses said the extended age of the bones means the investigation falls outside the jurisdiction of the police department.

Melanie Chinen, head of the Historic Preservation Division, said her agency will determine whether to leave the skeleton where it is or rebury it elsewhere.

"I know our staff responded to it under our jurisdiction," she said. "Right now the staff is looking to come up with a long-term preservation plan for that particular burial."

Chinen declined to speculate in detail about the bones on the beach.

Ortiz and others who were there said two women from the division who examined the bones indicated that they were that of a man. They also said because the skull's teeth remained intact, it indicated that the bones were not ancient.

Ortiz said the right jaw of the skull appeared to be "smashed in," leading him to wonder if the person might have been the victim of foul play or killed in an accident.

Alvin Kama, 45, a homeless man who has lived on the beach for years, said human bones have been found elsewhere in the area in the past. But this was the first time a human skull had appeared on the beach, he said.

Richard Beralas said he was one of several people who found what appeared to be the bones of the lower part of a human skeleton there a week or so ago. Those bones were found very near to where yesterday's skeleton was found.

But Beralas, 46, said a game warden who examined the earlier discovery said those bones were most likely that of a wild pig.

Reach Will Hoover at whoover@honoluluadvertiser.com.