HILTON HEAD ISLAND, S.C. — An alligator ate a shark off a South Carolina island, and scientists say the oft-feared fish may become a staple of the reptile's diet.

The Island Packet of Hilton Head reports a 7-foot (2.1-meter) alligator named Charlie was filmed gobbling up a bonnethead shark Friday in a confrontation between what scientists call ancient enemies.

Charlie dined in Skull Creek, saltwater beyond his normal habitat. Alligators typically lack the saltwater glands to survive in coastal waters, but American alligators are gaining tolerance.

Duke University ecologist Brian Silliman is the lead author of a study that posits predators are reclaiming habitats from which humans displaced them. He says the encounter represents "the old norm." And a 2017 study in Southeastern Naturalist found alligators will eat at least four types of sharks.