When an alligator bares that jagged grin at you, it’s showing some six dozen huge teeth. The beasts have been around for a 100 million years.

So, finding a fossil alligator tooth in the Lowcountry should be a breeze.

After all, fossil shark’s teeth routinely turn up in places as diverse as Sawmill Branch Canal in Summerville and quarries in Harleyville.

Larry Taylor of West Ashley has pulled shark’s teeth from the Shadowmoss Golf Club course. He and his children picked them up by the pocketful when the Glenn McConnell Parkway was under construction.

But he’s never found an alligator tooth.

“It just seemed odd,” he said.

Not so much, it turns out.

First of all, a shark has a few rows of teeth in its mouth, set in the gum rather than embedded in the jaw like the gator.

“Gators have a single row of teeth,” said Lou Guillette, who researches toxicity in alligators at the Medical University of South Carolina. “They will replace those lost but that is not exceedingly common.”

So, while a shark loses and replaces a tooth every week or so, a gator’s tooth is usually worn down to nothing by the time it’s lost.

There are hundreds more shark species than the few crocodilian species; sharks have been around four times longer, said veteran fossil collector Paul Bailey.

“So for every million shark’s teeth, there may have been only one alligator tooth,” Bailey said.

Rare as they are, fossil gator teeth can be found here. Bailey said they have been pulled from the Chandler Bridge Formation, ancient sand deposits where other marine fossils are found.