Molly Sampson, a nine-year-old fossil hunter, found a giant ancient shark tooth on Christmas Day (Credit: Alicia Sampson)

Nine-year-old Molly Sampson and her 17-year-old sister Natalie had only one item on their Christmas list last year. They wanted chest-high waterproof overalls to "go shark's-tooth hunting like professionals." Their wish was granted. On Christmas morning, the sisters set out to Maryland's Calvert Beach with their father to put their new equipment to use.

Though it was a frigid 10° F (-12° C), Molly was undeterred. With the tide particularly low, she walked deep into the ocean. In less than half an hour, the fourth-grader noticed "something big" just beneath the surface of the water. To her delight, it was exactly what she was hoping to find: a megalodon shark tooth.

Molly has a collection of over 400 shark teeth ( Credit: Alicia Sampson)

"We went out shark's tooth hunting around 9:30 because it was a low tide," Molly said. "And we're wading out in the water, and I looked over, and I looked down in the water, and I saw it, and I reached in and grabbed it."

The Sampsons took Molly's exciting find to the Calvert Marine Museum in Solomons, Maryland. Here, Dr. Stephen Godfrey, the Curator of Paleontology, confirmed that the massive five-inch tooth was indeed that of a megalodon. Molly estimates that its former owner was about 50 feet long.

"Every inch is 10 feet," she said. "So this is five inches, so it'd be 50 feet, [a] 50-foot shark."

The Otodus megalodon ("giant tooth") is a species of mackerel shark that went extinct about 3.6 million years ago. The monstrous fish grew between 60 to 70 feet (18 to 21 meters) long. The apex predators ruled the seas and ate anything they desired.

The biggest and smallest shark teeth in Molly's collection (Credit: Alicia Sampson)

The waters off Calvert Cliffs were once home to whales and dolphins that would have attracted hungry megalodons and other shark species. Sharks frequently lose their teeth and replace them with new ones. As a result, the area is a treasure trove for amateur fossil hunters looking for shark teeth. While over a hundred are found annually, few are as large as the one Molly found.

"There are people that can spend a lifetime and not find a tooth the size Molly found," said Godfrey.

This is not the first time Molly has found a shark tooth. Over the years, the young girl has collected over 400 shark teeth along Maryland's coast. She suspects at least six of them once belonged to megalodons!