Two boaters found what they thought was a human jawbone while scavenging for collectibles Sunday under the Arthur Ravenel Jr. Bridge.

A Georgetown man and a friend from Hartsville were boating in the Cooper River when they stopped to look for old bottles on Drum Island, which is under the Charleston side of the bridge.

During their hunt, they came across what appeared to be the lower half of a human jaw, according to a police incident report.

The men returned to shore with the bone in their boat, and they called the Mount Pleasant Police Department about 7:30 p.m. Sunday.

The police report stated that the bone was entered into evidence and that the Charleston County Coroner’s Office would look into its origin at a later time.

Uninhabited by people, Drum Island has served as a disposal site for dirt dredged from the depths of Charleston Harbor. It’s also a popular roosting ground for birds and breeding area for mosquitoes.

Reach Andrew Knapp at 937-5414 or twitter.com/offlede.