A favorite pastime of recreational divers exploring the waters off Florida’s coast is hunting for teeth of the monstrous megalodon. A nightmarish prehistoric predator, the megalodon was an enormous shark species that’s been extinct for some 2.6 million years. Now in summer 2016 one particular diver was hunting for the elusive teeth of this beast from a bygone era. And yet he found something that was in fact much rarer.
These megalodon teeth that so many divers go in search of are, it’s worth noting, pretty awesome; and you can get an idea of just how awesome from this photo, which shows two great white shark teeth next to a single megalodon tooth. It’s therefore easy to see why divers might get excited about finding a tooth from this giant creature – which could attain lengths of almost 60 feet.
But what about our diver’s discovery? Well, first off, he was specifically exploring the waters just off Manasota Key, some 15 miles south of Venice, Florida. And as for the find itself, what he stumbled across was a piece of bone, covered in barnacles, situated around 20 feet underwater and 300 yards off the shoreline.
Initially, though, the diver didn’t actually realize what it was that he had picked up off the ocean floor. And so, when he got the bone home, he left it sitting out on a paper plate. It wasn’t until two weeks later that it occurred to him that it might be a piece of human bone.
Once that realization had hit him, however, our Florida diver took a photo of the bone – actually a fragment of jawbone – and sent it off to the Florida Bureau of Archaeological Research. So it was that the snap ended up on the desk of underwater archaeology supervisor Ryan Duggins. What’s more, the expert was immediately intrigued by what he saw.
Duggins observed that the fragment of human jaw still had one tooth attached to it. And the especially noteworthy feature of the tooth was that it had been worn down such that it lacked any of the points that human teeth possess. This telltale sign usually indicates that an individual has lived on a coarse diet.
Furthermore, the smoothened nature of the tooth revealed something of great interest. Speaking to National Geographic, Duggins said, “That’s something we don’t see in modern populations, so that was a quick indicator [that] we were dealing with a prehistoric individual.” This bone was, then, almost certainly not contemporary.
Duggins subsequently went to the site where the jawbone had been discovered and began a survey of the area with a team of underwater archaeologists. Speaking later, Duggins remembered, “As soon as we were there it became clear that we were dealing with something new.”
The investigating diver-archaeologist then quickly came across a fractured arm bone. And next up he saw a group of timber posts that had clearly been hand-carved. There were also three pieces of skull visible in a dip in the seabed. It was at this point that Duggins first realized that what he was surveying was almost certainly an ancient Native American graveyard.
This type of cemetery is known as a bog burial site; and it was the first one that had ever been discovered in the Americas under seawater. Yet to understand why this graveyard is under 20 feet of ocean in the 21st century, we need to know a bit about the historical geography of this part of the Florida coast.
At the time of the last ice age – when mammoths, saber-toothed tigers and giant beavers roamed the Florida landscape – the ocean covered much less of the land. However, when the last ice age began to wind down some 14,000 years ago, rising sea levels started flooding Florida’s coastal regions.
Where once the Florida peninsula had been a broad landmass, now it became the thinner spike of land familiar to us today. So before those coastal regions were flooded, the site of this ancient burial ground would actually have been a shallow freshwater pond.
Two of the wooden stakes that Duggins and his colleagues had found were in fact used to date the site. These posts had been grave markers, and radiocarbon dating now established that they were around 7,200 years old. That places them as having been used in what archeologists call the “archaic period.”
During that era, the Gulf of Mexico was around 30 feet shallower than it is nowadays. So, scientists were able to calculate that this burial site, now 21 feet below sea level, must have been about nine feet clear of the waterline when it was in use. Like many other sites used by the ancient peoples of Florida, over the centuries it became inundated.
Now a key factor has contributed to the preservation of these bones that were interred more than 7,000 years ago. The bottom of the freshwater pond where the remains had lain featured deposits of peat – accumulated vegetation that had decomposed. And peat is an ideal medium for the preservation of organic remains that would otherwise have disappeared in the seawater.
Other graveyards of ancient Americans whose bodies were buried and preserved in peat have, in fact, previously been discovered. However, all of those sites were unearthed on dry land rather than under the sea. One such discovery was the 8,000-year-old Windover site, which was uncovered accidentally in 1982 by construction workers near Cape Canaveral. That site yielded the remains of 168 individuals, half of them children.
Back in the present, Duggins outlined contemporary theories about the burial practices of those who’d used the Manasota Key site. “What we currently are thinking is that when an individual passed, they would have been wrapped in handwoven fibers and sunk to the bottom of the pond,” he said.
“A series of fire-hardened and sharpened stakes would [have been] pounded into the pond bed around the body, with the tops of those stakes protruding above the water line,” Duggins continued. Up to now, the remains of six individuals have been discovered; however, Duggins believes that there will be many more. Indeed, he estimates that the graveyard might even cover an entire acre.
At present, the bones and artifacts that have been removed are being held at the Florida Gulf Coast University’s Forensics Studies Lab. There, they are undergoing a painstaking preservation process of drying and desalination so that they can be studied in greater depth.
For now, though, the key concern for Duggins and the Bureau of Archaeological Research is ensuring that the human remains are treated with proper reverence. In a statement from the Florida Department of State, Duggins said, “Seeing a 7,000-year-old site that is so well preserved in the Gulf of Mexico is awe-inspiring. We are truly humbled by this experience. It is important to remember that this is a burial site and must be treated with the utmost respect.”