A human jawbone that was found on an island under the Ravenel Bridge last week has not been identified, but investigators have ruled out a couple possibilities.

The bone did not come from Gayle McCaffrey or Brittanee Drexel, two high-profile missing persons, the Charleston County Coroner’s office said Tuesday.

It had not been determined Tuesday if the jaw came from a male or female.

Boaters looking for bottles on Drum Island found the lower half of a jaw and turned it over to authorities.