Pleistocene fossils are nothing new in South Carolina. They have been found in good numbers on land sites, and scuba divers in our coastal rivers find many well-preserved fossils every year. But sites with associated or articulated Pleistocene fossils are very rare on our coastal plain. And never has a site been found in this state with so rich an assemblage of animals, some lying right where they died thousands of years ago, buried in sands and clays after a massive flooding event. At least, not until now... For the last few months, the S.C. State Museum has been methodically unearthing a maze of meandering river paleochannels of sand, richly abundant with fossils, and writing a new chapter about South Carolina's ancient past in the process.
This fossil-rich site is located at the Giant Cement quarry, an active limestone mining operation. The Giant quarry has been a favorite haunt of fossil collectors for many years. Although the Giant Cement quarry is well known for its Eocene marine fossils, there have been some notable Pleistocene terrestrial fossil discoveries made there from time to time, as for example the Ardis local fauna, published more than 10 years ago. Mammal fossils representing a number of genera have been found in the overburden dirt that is removed so Giant Cement can mine the underlying limestone. For many years knowledgeable collectors have been searching the overburden piles, slopes and wall faces looking for the prized specimens that occasionally appear. During the last two years in particular, more and more Pleistocene mammal fossils were showing up on the dirt slopes and three collectors in particular were hot on the trail, looking in the vertical back walls of the quarry for the strata producing these fossils. Finally, last spring, while collecting with other seasoned experts, veteran collector Rick Carter spotted a layer of sand that was exposed for the first time on the back wall of the quarry. To his eyes, it looked "out of place," wedged between thick layers of clay eight feet below ground level. As a very experienced collector, he suspected this layer might contain fossils, and only a few minutes of digging proved him correct. The coloration and preservation of those initial fossil finds indicated that this was the layer that the collectors had been looking for.
For several months the layer was dug by private collectors, but since no data were collected with these fossils they were of no particular research value in future publications. A few fossils were donated to the South Carolina State Museum during this time, primarily a very few mammal limb bones and bird bones, but not the more important skulls and mandibles. Realizing the tremendous importance of these fossils, the State Museum contacted the CEO of the quarry and requested permission to conduct a scientific excavation of the fossil formation, and in late July the quarry owners set aside a significant area for the S.C. State Museum. The Giant Cement company generously provided the use of track hoes for overburden removal, offered storage facilities for equipment and fossils, granted permission for media coverage, and by countless other means provided assistance without which this dig would have been impossible. Their invaluable cooperation continues to this day. By late September, the overburden was removed from the site (a major safety consideration!) making the excavation go more easily and safely. A grid system was established to locate fossil associations.
And then the digging began....
The final foot of overburden was carefully removed, layer by layer, and compass orientations were taken on the long bones as they were uncovered to determine the direction of water flow when the bones were deposited. After interpreting these initial data, the working hypothesis is that the bones were buried quickly during a flood event, perhaps even resulting from heavy rains during a hurricane. Almost none of the bones show any signs of predation or scavenging, so it is believed that they were buried quickly and lay undisturbed by hungry animals. During floods, the juveniles and older animals are the most common drowning victims, and the majority of the mammals excavated so far seem to support this trend.
Present efforts center on the systematic excavation of channels filled with sandy matrix that overlie an uneven layer of limestone. These sand-filled channels are believed to be the final drainage areas where the water flowed as it receded, and where the drowned carcasses of the animals were finally deposited. During the flooding, the water was flowing over an uneven layer of exposed limestone, creating some deeper pockets that filled with sand and sediment. It is in these deeper pockets that the larger fossils, such as skulls and mandibles, are often found. Some of the bone masses are associated, or are articulated as was one sloth, while others are scattered over a small area, and many are isolated specimens. In some areas the bones are so abundant that when removing one bone, other bones will be found touching or lying underneath it, so the fossils have to be removed sequentially like in a game of "pick up sticks." The larger and more fragile fossils are wrapped in plaster or tin foil jackets, and all other fossils are wrapped in tissue and stored in bags labeled with the location data.
The digging has so far produced fossils from over 20 species of vertebrates representing more than 15 families, including a significant megafauna, several smaller mammal species, and a few micromammals. When the collecting first began, two species of camels seemed to comprise the majority of the larger animals found. Since there were a lot of camels found, the site became officially known as "Camelot." It soon became apparent that the bone bed was very diverse and the list of species grew quickly. The list of mammals now includes horses, deer, giant armadillos (northern pampathere), a smaller armadillo, wolf, mountain lion, giant sloth, tapir, peccary, several species of terrestrial turtles, tortoises, and birds. In addition, five saber-toothed cat skulls (either mostly complete or partials) have been found. As a bonus, layers of carbonized plant remains, including pollen, seeds, leaves, twigs and nuts were found and these will be used to determine the flora and the climate during the time the fossils were deposited.
The initial working hypothesis of the age of the site was stated to be the same as the Ardis local fauna, about 19,000 years old (late Rancholabrean). As with all working hypotheses, however, new data allow for alteration of the interpretation. It is now believed that the Camelot local fauna is considerably older, and appears to be late Irvingtonian in age (250,000 to 500,000 years).
Data collection has been hindered by the recurrent invasion of thieves to the site. We have gone out to the site to find it plundered by trespassing vandals who have gone so far as to remove the grid system stakes so that they could dig where the stakes were. If caught, the criminals will be prosecuted by Giant Cement to the fullest extent with a series of felony-level offenses, such as Criminal Trespass, Grand Theft, and Receipt of Stolen Property.
The site is currently being worked by museum staff and volunteers, with occasional assistance from visiting paleontologists, and expert help from some of the staff from the Smithsonian's paleobiology department. Once the fossils have been collected and cataloged, other museums will be contacted to assist in identifications and data interpretation. Synoptic collections will be shared with other museums, as we have done in the past.
The work continues as steadily as possible, keeping in mind the very hot, humid summer weather that lies ahead. Unfortunately, the number of volunteers working on the site is limited, due to insurance and safety concerns by the quarry owners. And of course, the site is closed to all other collectors and is securely guarded.
The Camelot site has proved to be one of the richest Pleistocene sites ever excavated in the Southeastern U.S. outside of Florida. Data collected from the site will provide insights into the taxonomic status, geographical distribution, habitat preference, and extinction dates of some species. The sheer numbers of specimens, the faunal diversity, and the excellent preservation of the fossils will provide not just a peek back into time, but more precisely, a panoramic view of life in South Carolina hundreds of thousands of years ago.
Vance McCollum and
Jim Knight, Director of Collections and
Chief Curator of Natural History
S.C. State Museum