A Lost Megalodon Backbone Points to an 80-Foot, Century-Old Shark — What It Means for SC Tooth Hunters

Almost everything we know about the size of Otodus megalodon comes from its teeth. That is no accident. A shark's skeleton is cartilage, and cartilage rarely survives the millions of years between a living animal and a collector's hand. So when a set of genuine megalodon vertebrae turns up — and then disappears for decades — it matters. This summer a team led by DePaul University paleobiologist Kenshu Shimada published a full study of exactly such a specimen, and its numbers are worth unpacking for anyone who has ever pulled a megatooth out of a Lowcountry riverbed.

A Backbone Lost and Found

The fossil, catalogued as NHMD 157890, was excavated in 1978 from a clay pit at Gram in southern Denmark. The Gram Formation there is Late Miocene in age, about 10.8 million years old. When it was first reported in the early 1980s, the find was described as roughly 20 associated vertebrae from a single shark — an extraordinary thing for a species known mostly from isolated teeth.

Then it vanished from view. The specimen was damaged during a collection move in 1989 and was widely assumed to be lost. It eventually resurfaced in the holdings of the Natural History Museum of Denmark, where a collection manager recognized it. What survives today is sobering: two partial vertebral centra and at least 185 smaller fragments. The new paper, published in Palaeontologia Electronica in June 2026, is the first detailed look at what remains.

The Largest Fish Vertebra on Record

The headline measurement is the width of the biggest centrum: 23 centimeters, or about 9 inches, across. According to the authors, that makes it the largest shark vertebra known — and, as far as they are aware, the largest vertebra of any fish ever recorded.

To turn a vertebra into a body length, the team leaned on the best megalodon skeleton anyone has: a vertebral column from Belgium (IRSNB P 9893) whose largest centrum measures 15.5 cm and which belongs to an animal estimated at 16.4 meters. Scaling up proportionally from that individual gives the Danish shark a length of about 24.3 meters — close to 80 feet. That figure lines up with a 2025 study, also led by Shimada, which argued that 24.3 m is the largest size the current fossil record can reasonably support, and that megalodon was likely a longer, more slender animal than the "giant great white" of popular imagination, with proportions closer to a modern lemon shark.

The authors are careful to call the length a working hypothesis. It assumes the Danish and Belgian sharks were built alike, and that the biggest Danish centrum sat at a comparable position in the spine.

Reading the Rings: A Shark That Lived for Decades

Shark vertebrae lay down growth bands somewhat like tree rings. Using micro-CT scanning, the team counted 64 bands in the better-preserved centrum, and they note that this may be a conservative undercount. If each band represents a year — the usual working assumption — this shark was at least 64 when it died.

Fitting those bands to a standard growth model, the researchers estimate a newborn megalodon of around 3.6 meters (about 12 feet) and a possible theoretical lifespan of about 96 years. They stress that the growth model should be treated as highly tentative. Still, the picture is striking: an animal that started life longer than most modern adult sharks and could keep growing for the better part of a century.

A Hint at the Last Meal

One more detail stands out. Gill rakers and scales from a basking shark were found in close association with the megalodon remains. The authors suggest these may represent the megalodon's stomach contents, which would be the first such evidence in the species' fossil record. They are explicit that this is a hypothesis — remains can end up side by side for many reasons after death — but it is an intriguing counterpoint to the familiar image of megalodon as a whale specialist.

Why South Carolina Has the Teeth but Not the Backbones

Anyone who dives the blackwater rivers around Charleston knows the pattern: megalodon teeth turn up in the gravel, vertebrae essentially never do. There are good reasons for that.

• Teeth are made to last. A megalodon tooth is capped with enameloid, among the hardest tissues in any vertebrate. Vertebrae are calcified cartilage — mineralized, but far more fragile.
• Sharks shed teeth constantly. A single animal replaces its teeth over and over through its life. If megalodon really lived for several decades, one shark could have scattered a remarkable number of teeth across the sea floor, while leaving behind only one skeleton.
• Lowcountry fossils are reworked. Most river finds have been eroded out of their original formations and tumbled into lag gravels. That process concentrates tough teeth and destroys delicate material. The Danish vertebrae survived because they were buried in quiet clay — and even they broke into nearly 200 pieces after excavation.

The newborn estimate offers a useful reminder too. If megalodon pups were already around 12 feet long, then the smaller megatooth teeth in a South Carolina collection can still come from sizable animals. A modest tooth is not evidence of a small fish, and tooth size alone says nothing precise about an individual's age.

What Your Tooth Can — and Can't — Tell You

Collectors often ask how big the shark behind a given tooth was. Published methods do exist: some scale body length from the crown height of specific upper front teeth, while others use the combined crown widths of a tooth row. But the results shift depending on where in the jaw a tooth sat, and an isolated river tooth rarely tells you that with confidence. The Danish study is a reminder of how much those estimates still lean on very few skeletons. The authors say outright that a more complete megalodon specimen, ideally with teeth still associated, is needed before anyone can settle the question of maximum size.

That is where amateur finds genuinely matter. If you ever encounter something unusual — a large, disc-shaped centrum, or teeth that appear to come from the same individual — photograph it in place, keep associated pieces together, and contact the Charleston Museum or the South Carolina State Museum. For river collecting, make sure you are operating under South Carolina's hobby diver rules; our guide to South Carolina fossil hunting laws and locations covers the details, and our explainer on the Otodus lineage puts megalodon in its evolutionary context.

The Bigger Picture

Eleven million years ago, a very large, very old megalodon died in a sea over what is now Denmark. Its backbone was found, lost, and found again, and it now anchors the best-supported upper limit on how big the species could get. The teeth that South Carolina's rivers yield come from the same ocean-spanning species — and from animals that, this study suggests, may have patrolled for decades, shedding teeth the whole time. Each one we find is a small piece of a life that may have been far longer than anyone used to think.