Despite the wealth of information provided by this fossil site, only a few scientific studies have been published about it, so I had to piece together information gathered from those sources with that from websites written by amateur fossil collectors lucky enough to have been invited to the dig.
Location of Harleyville, South Carolina. There is an impressive fossil site here.
The fossil hunting grounds formerly owned by Lafarge cement company. Last year, they sold it to a South American company that forbids fossil collecting. Photo by Ron Ahle.
Ancient hurricane storm surges repeatedly flooded the South Carolina low country hundreds of thousands of years ago. Each of these floods drowned numerous animals, especially the young and old individuals too weak to swim through the surge, and then carried the corpses until snagged by an impediment. The landscape here consists of uneven ridges formed by Eocene-age limestone deposits originating from when this was a marine environment. During Pleistocene floods these above ground ridges acted as dams, trapping and accumulating bones which were quickly covered with sediment, thus becoming lag deposits. About 20 years ago the Lafarge Cement Company began bulldozing the fossil rich dirt to reach the underlying limestone which is used to make cement. They dumped the fossils and dirt into spoil piles and many amateur fossil hunters trespassed the site and combed through the fossiliferous mounds. Paleontologists caught wind of the treasure and were granted permission to collect here. They named the site “Camelot” for the abundance of llama fossils. Llamas are members of the camel family.
Paleolama mirifica, the stout-legged llama. Unlike all modern species of llamas and camels which inhabit arid or montane grasslands, the 2 species that inhabited the southeast during the Pleistocene were animals that either lived in forests or forest edge environments.
Skeletel reconstruction of Hemiauchenia macrophela, the large-headed llama. This was another common species found at the Camelot fossil site.
Camelops hespernus, yesterday’s camel–another extinct Pleistocene species of camel. This once common species formerly found in western North America did not live in the southeast as far as we know. Nevertheless, I wanted to include an illustration of this impressive animal in my article.
The scientists who originally catalogued the fossils and published the results estimated the fossils from the site dated to 19,000 BP and referred to it as the Ardis local fauna. Unfortunately, this study was published in an extremely obscure and now defunct journal, and I haven’t been able to find out how they came up with this age estimate. Scientists continued excavating Camelot and by 2003 determined the site was much older than that based on the physical characteristics of the extinct species. The fossils resemble mid-Pleistocene representatives of species rather than those from the late Pleistocene. Now, the mammal fossils here are considered to be between 250,000-400,000 years old which might put them in the Irvingtonian Land Mammal Age, not the Rancho La Brean, though the fossils may have accumulated at different times following different flood events.
The original catalogue of species listed dire wolf, a late Pleistocene species, but later excavations found Armbruster’s wolf, a mid-Pleistocene species. The dire wolf specimen may have been misidentified based on the inaccurate chronological assumption of the first study. Likewise, a specimen of Bison antiquus, a late Pleistocene species, may have been misidentified and was probably an earlier form of bison.
One of the few studies of the fossils found here examined carbon isotope ratios in the bones of white tail deer, Vero tapir, stout-legged llama, large-headed llama, horse, Jefferson’s ground sloth, saber-tooth, and Armbruster’s wolf. By examining the carbon isotope ratio in the bones, scientists can determine what kinds of foods these long dead beasts were eating. Plants growing in forests tend to have high amounts of carbon-3; plants growing in grasslands tend to have high amounts of carbon-4. They found that deer ate the highest amount of forest vegetation. Jefferson’s ground sloths, Vero tapirs, and stout-legged llamas also heavily relied on forest vegetation. Large-headed llamas were mixed feeders. Horses depended upon grassland. Armbruster’s wolves mostly ate forest dwelling herbivores. Saber-tooths inhabited mixed woodland and grassland environments where they ambushed prey. The scientists didn’t analyze bone from the mid-Pleistocene cheetah (Miracynonyx inexpectus), but they assume this was the primary predator of the grasslands.
Paleobotanists found macrofossils of cypress trees, water lillies, water milfoil, and algae as well as pollen from pine, hickory, oak, hazelnut, sweetgum, grass, and composites (daisies, sunflowers, etc.). During the time of deposition the site must have been a cypress swamp surrounded by an upland environment consisting of oak and pine woods mixed with substantial meadows. Hazelnut apparently was common in the deep south during cool climate phases, but it no longer naturally ranges south of the Appalachians.
Bird fossils were excavated here, but to learn which species, I’m going to have to spring for a back issue of Current Research in the Pleistocene because the info from that study is not available online.
A new species of extinct giant tortoise, still undescribed in the scientific literature, was unearthed here as well as many other freshwater turtle specimens. The Eocene-aged limestone underneath the Pleistocene deposit holds many fossil shark teeth and other marine specimens, making this site a kind of double bonus for paleontologists. Below is a list of mammal species that I’m aware were found here.
short-tailed shrew
southeastern shrew
star-nosed mole
eastern mole
beautiful armadillo
northerm pampathere (a giant armadillo the size of a bear)
Jefferson’s ground sloth
mink
river otter
striped skunk
spotted skunk
hog-nosed skunk
Armbruster’s wolf
gray fox
raccoon
Florida spectacled bear
jaguar
bobcat
saber-tooth (over 5 skulls)
mid-Pleistocene cheetah
13-lined ground squirrel
gray squirrel
southern flying squirrel
beaver
giant beaver (Castor ohioensis)
rice rat
cotton rat
field mouse sp.
woodrat
meadow vole
pine vole
Florida muskrat
southern bog lemming
Florida bog lemming
horse
Vero tapir
long-nosed peccary
Paleolama
large-headed llama
bison sp.?
mastodon
mammoth
References:
Beaty, Melissa
“Paleoecological and Depositional Environments of a Middle Pleistocene Vertebrate Fossil Locality in Harleyville, South Carolina”
GSA abstracts March 2007
Bentley, C.C. ; et. al.
“The Mammals of the Ardis Local Fauna (Late Pleistocene), Harleyville, S.C.
Brimleyana 21: 1-55 1992
Kohn, Matthew; et. al.
“Dining in the Pleistocene–Who’s on the Menu?”
Geology 2005
May 25, 2012 at 5:14 pm |
I’m always amazed at the wealth of mammal life that was here in North America before humans came along and killed them off.
May 8, 2016 at 11:03 am |
You have confused the two separate and distinct sites and faunas. The two faunas were about half a mile from each other and separated by at least 380,000 years!
The Ardis Local Fauna was carbon-dated at 18,940 plus/minus 760 years YBP (years before present), based on mammal and turtle bone collagen. The fauna is Rancholabrean in age (late Pleistocene).
The Camelot fauna was dated biostratigraphically at 400,000 to 450,000 years old, based on the species present and on the evolutionary grade of some of the species when compared to dated Florida sites that were studied radiometrically. This fauna is dated to late Irvingtonian/earliest Rancholabrean, or late middle Pleistocene.
There were no bison in the Camelot fauna because the fauna was deposited well before bison appeared in the North American fauna. Bison are present in the Ardis fauna.
There were a number of other papers published on these two sites.
May 8, 2016 at 12:52 pm |
Thanks for clearing that up.
That explains my confusion.
I haven’t been able to find much in the scientific literature about these 2 sites.