An excavation crew recently made a startling discovery at the bottom of Pearl Harbor when it unearthed a skull that archeologists suspect is from a Japanese pilot who died in the historic attack on Dec. 7, 1941.

Archaeologist Jeff Fong of the Naval Facilities Engineering Command Pacific described the discovery to The Associated Press and the efforts under way to identify the skull. He said the early analysis has made him "75 percent sure" that the skull belongs to a Japanese pilot.

He did not provide specifics about what archaeologists have learned about the skull, but said it was not from one of Hawaii’s ancient burial sites. They also contacted local police and ruled out the possibility that it’s from an active missing person case, said Denise Emsley, public affairs officer for the Naval Facilities Engineering Command Hawaii.

The items found with the skull provided some clues: forks, scraps of metal and a Coca-Cola bottle Fong said researchers have determined was from the 1940s.

Fifty-five Japanese airmen were killed and 29 of their aircraft were shot down in the attack, compared with the 2,400 U.S. service members who died. No Japanese remains have been found at Pearl Harbor since World War II.

The USS Arizona Memorial, which sits on top of the battleship that sank during the attack, still holds the bodies of more than 900 men. 

The skull remains intact despite being dug up with giant cranes and shovels.

It was April 1 when items plucked from the water during the overnight dredging were laid to dry. When it was determined a skull was among the dredged items, contractors were ordered to stop the work, Emsley said. 

"We definitely wanted it to be handled correctly," she said. 

The Joint POW/MIA Accounting Command on Oahu, charged with identifying Americans who were killed in action but were never brought home, has been asked to determine who the skull belongs to. The cranium was turned over to the command’s lab for tests that will include examining dental records and DNA, said John Byrd, the lab’s director and a forensic anthropologist.

"We’re working on the case but the case is just in the early stages of analysis," he said. "We’re not going to know much more about it for a while yet."

The lab is the only accredited Skeletal Identification Laboratory in the United States. JPAC has identified more than 560 Americans since the command was activated in 2003. When more information is gleaned from the skull, other agencies could get involved including the Naval Criminal Investigative Service and the Japanese Consulate.

Daniel Martinez, the National Park Service’s chief historian for Pearl Harbor, said experts on Pearl Harbor know enough about the specific location where Japanese planes went down in the attack that they might be able to match the skull with a crewmember.

Martinez said that beyond the historical significance of the finding, it is a reminder of a life lost. 

"I think that anytime you’re able to reclaim a casualty and perhaps even identify it, regardless of what country, it may bring closure to a family," he said.