Going to the beach? Bring a bag to carry the Ice Age mammal fossils

2 Nov 2006 | Ms. Amy Segreti

Fifty years ago, Rita McCabe didn’t even know what a sand-dollar looked like. Today, the Jacksonville resident is the owner of a considerable fossil collection which includes mastodon teeth, mammoth molars, whale vertebrae and shark’s teeth of every imaginable size. And the majority of her collection comes right from the shores of Camp Lejeune’s Onslow Beach.McCabe came to the area in 1953 when her husband was stationed on base. She’s been gathering up treasures at Onslow Beach ever since and considers the strand a “best-kept secret” among those interested in fossil hunting. “You can go to Topsail or Surf City and find wonderful shells, but there’s not another spot around where you can find the things you can find at Onslow Beach,” said McCabe.She’s collected fossilized wood, a bison horn, the jaw bone of a horse and porpoise teeth. The Smithsonian Institute has taken an interest in her collection and sent representatives to look at her specimens, which she keeps carefully tucked away in her home. She’s currently trying to figure out if she’s found a porpoise skull or not.“It’s been so much fun to tell the young Marines over the years — if you’re going to be stationed here and you get bored on a winter weekend, get out there after a storm or a good rainy, windy day and you’ll find some absolutely amazing things,” said McCabe.Retired Master Sergeant Ray Smith would have to agree. His finds at Onslow beach include a fossilized Jeffersonian ground sloth’s toe bone, named for discoverer Thomas Jefferson, and rib bones of manatee ancestors.But where are these rarities coming from? Fossils are found on beaches due to varying sea levels throughout the ages, causing the ocean’s edge to repeatedly rise and fall.“Marine fossils from mostly inshore environments were laid down as far west as Interstate 95,” said Richard Chandler, member of the North Carolina Fossil Club and the editor of club’s newsletter Janus. Erosion caused the fossils to migrate and today the entire coastal plain is rich in fossils, which can be found anywhere from the surface to several hundred feet underground.Onslow Beach in particular has a tendency to produce significant findings. Unlike most North Carolina beaches, it’s not just a sandbar. “Onslow Beach cuts into sediment areas and it’s also underdeveloped, so you don’t get a lot of sandbagging,” said Cindy Muston, president of the NCFC. The beach was once part of a reef system and dates back to the Oligocene Age — anywhere from 25–38 million years ago.Relics such as lion paws, camel ankles and horse bones that have washed up on Onslow Beach likely come from the embayment the beach faces, which was an animal-rich, near-shore environment during the early-mid Miocene Age (15–20 million years ago).But why are mastodon and mammoth fossils lurking on Onslow Beach? According to Chandler, these and other large Ice Age mammals probably died inland and their carcasses washed down rivers toward the ocean to be scavenged by sharks and other animals. “The bones would have been deposited mostly close to shore and then would have washed ashore at Onslow and other beaches,” said Chandler.The best conditions for fossil hunting occur directly after a storm. “Storms like a nor’ eastern, a hurricane or even a smaller storm will make the currents stronger and throw more onto the beach,” said Muston.Also, seasonal changes reflect changes in the amount of sand on the beach — there’s more sand on the beach in the summer and less in the winter. Because of this, heavier, denser objects are more likely to be exposed on beaches in the winter. “You have to compensate for the cold, but your chances of finding [fossils] in the winter are much higher,” said Muston.When you find something, the best thing to do is to let people know so that if you do have something unusual, the scientific community is aware of it, according to Vince Schneider, curator of paleontology at the North Carolina Museum of Natural Sciences in Raleigh, N.C.If you’re not sure what you’ve found, you have several options. “Fossil fairs are one of the best places to get answers because you have a lot of experts in one place who can identify things for you,” said Muston. The NCFC is holding a fair this Saturday at the North Carolina Maritime Museum in Beaufort, N.C. from 10 a.m. – 5 p.m., where fossil collections will be on display and representatives from the Smithsonian Institute and the N.C. Museum of Natural Sciences will be able to answer questions. You can also contact a neighboring museum or e-mail a picture of your find to Muston (, who welcomes any questions fossil hunters have.Most importantly, take your time and don’t be surprised if you find yourself catching the “buried treasure hunter’s syndrome,” as Chandler called it.“There are all these buried treasures out there crying to be found,” said Chandler, who started his addiction when he found a scallop shell the size of a dinner plate near Aurora, N.C.“It’s a wonderful pastime,” said McCabe, who adores her precious shell collection just as much as her fossils. “It grows on you I say, it really grows on you.”