MARSHALL COUNTY, Iowa — Authorities in Iowa announced this week that a human jawbone found last month belonged to a prehistoric person.

The Marshall County Sheriff's Office said that on Aug. 11, a conservation staff conducting a biological and wildlife survey found a possible human lower jawbone in the Iowa River.

Officials said the jawbone was intact, but it had deteriorated to the point that they believed it was several years old.

Investigators also found three other potential human bones in the area, the department said.

According to the news release, the county medical examiner was called in to collect the findings and sent them to the state's medical examiner's office for more testing.

Well, on Wednesday, the sheriff's office said that examinations by the state's medical examiner's office revealed it belonged to a human.

It was then sent to the Office of the State Archaeologist at the University of Iowa for further examination, which later determined that it likely belonged to a prehistoric Native American man who was middle to older, the press release said.

According to the department, the other three bones were determined to be nonhuman.

This isn't the first time this year that receding water levels have led to discovered objects once buried deep underwater.

Since May, several human remains, and a World War II-era boat has been unearthed in Lake Mead.

In Texas, a lack of rainfall helped wildlife officials find 113 million-year-old dinosaur tracks in a dried-up river last month.