Historic preservation officials said they began negotiating with the new owner of a long-vacant home where the remains of 33 American Indians were found.

Finding such a large collection of remains is unusual, officials said Tuesday, and they hope the owner will donate the bones to the state for further study.

"We've been given a rare opportunity to open a window onto the past, 600 or 700 years ago, before recorded history in this state," said Dave Blanchette, spokesman for the Illinois Historic Preservation Agency.

American Indian groups have said they hope the remains are ultimately reburied. Blanchette said the state agrees, but "it's too early to speculate what might happen." He said they would not be displayed.

Officials said jawbones or partial jawbones of seven American Indians were found Tuesday during a search of the house, where complete skulls of 26 American Indians were found last week by a woman who bought the house in November.

The house was owned by a Bloomington dentist and avid collector of American Indian artifacts who died in 1982. Officials believe he dug them up in the 1930s at a site about 10 miles from Dickson Mounds Museum near Lewistown — more than a half-century before laws protecting burial grounds were enacted.

Dawn Cobb, an anthropologist with the historic preservation agency, said the dentist likely recovered the remains to study the teeth, some "beautifully preserved."

Dates written on bones and other artifacts found in the house helped trace the remains to an American Indian settlement that was active for about 500 years after it was founded in 1200, said Alan Harn, an archaeologist at Dickson Mounds.

Harn said the site was "essentially looted" as European settlers moved into the state, so the remains are likely the last collection that can be studied to provide insight into the Spoon River Mississippians who once lived in the region near the Illinois River.

Laws ban selling remains, but the homeowner, Kathleen Hollonbeck of Rochelle, could keep them or donate them to the state or another museum. Hollonbeck did not return a call for comment Tuesday.