Buzz
In Madagascar, researchers uncovered the fossilized remains of a horned crocodile inside a cave filled with water. Barry ColemanFlowing through South Carolina's lowlands, the Cooper River meanders past reed-filled shores, offering a sanctuary for fish and shorebirds. Originating from Lake Moultrie in Berkeley County, it continues southward to Charleston, where it joins the Ashley and Wando rivers to form the renowned harbor. If you’re familiar with Fort Sumter, you’ll know its historical importance.
Named after 17th-century English noble Anthony Ashley Cooper, the Cooper River played a key role in South Carolina's rice trade. Yet, its significance stretches back to even earlier, marking an ancient chapter in the region's rich history.
If you're equipped with the right scuba gear and know where to search, you could uncover a mammoth tusk hidden beneath the water’s surface.
Matthew Weas, along with his father Joe Harvey, is no stranger to the thrill of fossil hunting. As skilled local divers, they frequent the Cooper River in search of prehistoric treasures, many of which are later showcased at the Berkeley County Museum in Moncks Corner, South Carolina.
However, not all the creatures they encounter are from the distant past. According to Weas, encounters with modern river dwellers are common. He recalls having his hand swallowed by a catfish in an underwater log jam, spotting a manatee surface while swimming back to the boat, and even having alligators swim directly toward him. On one occasion, he came face-to-face with a 10-foot-long alligator.
This skull belongs to an extinct lemur, once part of Madagascar's primate community, which vanished in the last 1,100 years. Barry ColemanCave of Wonders
While the American alligator is often associated with the Southern U.S., underwater fossil hunting is a global activity. Divers have discovered ancient treasures in locations such as Australia, Bali, Brazil, Indonesia, Mexico, and the Bahamas.
In 2014, an extraordinary discovery was made in Madagascar’s Tsimanampetsotsa National Park: a true "lemur graveyard." This remarkable find was the result of a collaborative effort involving anthropologists, paleontologists, and scuba divers.
Beneath the water’s surface, hundreds of bones were uncovered. Some belonged to modern species like the invasive black rat, while others came from animals that had vanished in the last few thousand years.
The site quickly gained recognition as the largest collection of Pachylemur fossils in the world. This ancient relative of the ruffed lemur was about twice as heavy, weighing around 22 pounds (10 kilograms). It was dwarfed by the gorilla-sized Mesopropithecus, another massive lemur species found at the site.
The dive team also recovered remains of a pygmy hippo, an elephant bird, and a horned crocodile, in addition to a rare, nearly complete skull from another extinct lemur species.
Gaining access to this trove of fossils was no easy feat. The caves, once likely dry, are now part of a flooded sinkhole. The most fossil-rich cave in the system plunges 82 feet (25 meters) deep, with its dark, intricate layout filled with horizontal passages and murky water.
In short, this environment is far from suitable for inexperienced divers. Cave diving, in general, is a dangerous activity; straying off-course can prevent you from ascending directly to the surface. To stay safe, the expert divers in the 2014 team used 879 feet (268 meters) of safety lines to mark their paths.
This 30-inch section of Mastodon tusk was found during a dive in South Carolina's Cooper River. Joe HarveyPreparation Is Key
Another remarkable sinkhole site is the Page-Ladson location in northwestern Florida. Buried beneath the Aucilla River, it has produced some of the earliest human artifacts ever found in North America. Equally intriguing are the mastodon bones discovered there, including fossils that are around 14,550 years old and show signs of butchery by ancient Floridians.
Here, tannins are a real nuisance. A vital component in leather, tannins are chemical compounds released by various plants. When these seep into ponds or rivers, they can turn the water blackish-brown. Needless to say, this impairs visibility. In some corners of the Aucilla, the tannins help block out sunlight, shrouding everything deeper than 10 feet (3 meters) beneath the surface in inky darkness.
Back north in the Cooper River, divers face this same problem. To see clearly, they — and their Aucilla-based colleagues — make good use of high-wattage underwater lights.
Weas says he and his father wear Dive-Rite "cave lights" attached to their helmets. The rest of the duo's equipment would look pretty familiar to other recreational divers. "We use the standard tank, regulators and BCDs," Weas says. (For the record, BCD stands for "Buoyancy Compensating Device," a wearable gadget used to keep divers at their desired depth.)
On summer dives, Weas and Harvey can comfortably don pants and T-shirts. But under some weather conditions, dry suits, semi-dry suits or wetsuits might be more appropriate. Since the Cooper gets strong tidal currents, the water's speed at any given moment affects their schedule. Faster currents make for shorter excursions.
This cache from a dive in the Cooper River includes several shark's teeth as well as a brass Colonial belt buckle.
Joe HarveyGiant Sharks ... And Beavers?!
Why bother diving for fossils when so many are readily available on dry land? For one, water immersion offers significant preservation advantages. Deep within a submerged cave, bones are protected from the usual threats—scavengers and the harsh effects of open-air environments.
While land fossils are often encased in rock, river fossils benefit from the cleansing power of flowing water, where the bones are polished smooth by the currents.
The majority of fossils Matthew Weas finds in the Cooper River belong to two distinct geological periods. Among the river’s most prized treasures are shark teeth from the Miocene Epoch, which spanned from 23 million to 5.3 million years ago. Some of these teeth can grow impressively large: A megalodon shark's tooth can measure as much as 7.6 inches (19.3 centimeters)!
"Shark teeth are the most frequent discoveries," says Weas, "though whale ear bones come in a close second."
Other fossils found in the Cooper River date back to the more recent Pleistocene Epoch, which began about 2.6 million years ago and ended just 11,700 years ago. During this time, sea levels were lower, and the Carolina coastline extended further east.
Over the years, Weas and Harvey have uncovered bones from Pleistocene-era mammoths, capybaras, various hoofed herbivores, and even giant beavers. The latter requires some explanation. During the last ice age, North American wetlands were home to Castoroides, enormous 8-foot (2.5-meter) beavers that likely weighed over 220 pounds (100 kilograms).
Having a manatee sneak up on you can be frightening enough. But imagine sharing the waters with one of those gigantic, prehistoric rodents! I'll pass, thanks.
As recently as 8,200 years ago, Great Britain was still connected to mainland Europe. Because of this, mammoth bones are sometimes dredged up from the North Sea, the body of water separating the U.K. from its continental neighbors.
