CONTRIBUTED PHOTO — A human jawbone discovered in Marshall County near Timmons Grove Park in August likely belonged to a prehistoric Native American male, according to archaeological researchers.

After Marshall County Conservation staff alerted the Marshall County Sheriff’s Office of the discovery of a possible human jawbone while they were conducting a biological and wildlife survey along a remote stretch of the Iowa River near Timmons Grove on Aug. 10, further investigation has determined that the body part likely belonged to a ‘prehistoric Native American middle to older age male.’

The Marshall County Medical Examiner collected the remains and sent them to the Iowa State Medical Examiner’s Office, which determined that the mandible was confirmed as human with “no modern medical significance.” The other bones found at the scene were determined to be non-human.

From there, the jawbone was transferred to the Office of the State Archaeologist at the University of Iowa for further examination, where the “prehistoric” conclusion was reached, and additional historical research is expected.

Sheriff Joel Philips said the archaeologists who studied the jawbone were surprised by how well it had stayed intact over the years — several of the molar teeth were even still in place — and there were no signs of trauma, indicating that the individual who the jawbone belonged to likely did not die a violent death.

“It was kind of in remarkable condition for the time period,” Phillips said.

Phillips added that although there is a small chance the mandible belonged to a human who lived in the 18th or 19th century, the prehistoric period is still the most likely conclusion based on the evidence available. The conservation staff also determined there were about 10 Native American camps near Timmons Grove on the north shore of the river.

When the discovery was first announced in August, some social media commenters speculated on whether the jawbone could have belonged to a missing person or the victim of an unsolved murder in the area, and Phillips said the MCSO received six tips in the aftermath. Ultimately, however, archaeological research determined the mandible dated back much further.

“We always keep those cases in the back of our minds if something turns up in those areas,” Phillips said.