Monday, August 12, 2013

Big Bone Lick, Kentucky

The first major deposit of vertebrate fossils known in North America, Big Bone Lick is recognized as the birthplace of American vertebrate paleontology. The site is a swampy area surrounding salt- and sulfur-bearing springs, which large herbivores have been visiting since the late Pleistocene, some 18,000 years ago.
Model of a mammoth on display at Big Bone Lick State Park.
Site History and Discovery
The first major deposit of vertebrate fossils known in North America, Big Bone Lick is recognized as the birthplace of American vertebrate paleontology. Major Charles LeMoyne de Longueuil, commander of the French and Indian troops of Canada, was the first man known to have visited this site in 1739.  Ben Franklin would later visit this site and, later still, Thomas Jefferson sent William Clark to collect fossils in 1807. The three hundred bones that Clark recovered were split into three groups and sent to three different places; one set went to the American Philosophical Society in Philidelphia, another went to France's National Museum of Natural History in Paris, and Jefferson kept the third set. Some of these fossils are still on display today in Jefferson's Virginia home.The site is located 20 miles southwest of Cinncinati, Ohio. In 1839, de Longueuil returned to the site on a collecting trip and sent his fossils to France. Big Bone Lick State Park was established in 1960, and visitors today can view three full-sized replicas of Columbian Mammoth, American Mastodon, and Jefferson's Ground Sloth. Many of the fossils recovered from here now reside in museums around the world including London, Paris, and the University of Nebraska State Museum in Lincoln, Nebraska.

Black Bear bones are among the few non-herbivore
remains found at the Big Bone Lick site.
Site Details
Big Bone Lick is a swampy area surrounding salt- and sulfur-bearing springs. The presence of these mineral springs explains a very important detail about the animal remains that were found here; all of the mammal remains recovered here are from herbivores apart from a few wolf and bear remains. This fact records a very important aspect of herbivore behavior. Plant matter is very low in sodium, and so herbivores must obtain this vital nutrient usually by visiting mineral deposits, such as those found at Big Bone Lick. For this reason, herbivores have been drawn to this site for as far back as 18,000 years ago!

Researchers working on the site have identified three bone-bearing layers corresponding to different times in history. The lowermost horizon, the C-horizon, is a blue-gray sandy silt that contains the bones of extinct animals from 18,000 years ago. The middle layer, the B-horizon, represents a time less than 13,000 years ago and only contains the bones of extant species. The topmost layer, the A-horizon, recent animal bones alongside human artifacts.


The woodlands of Big Bone Lick were home to extant
White-tailed Deer as well as American Mastodon.
Paleoenvironment (C-horizon)
The herbivore bones found here are all disarticulated and many are broken, suggesting that some of the herbivores that visited this place were occasionally ambushed, killed, and eaten by predators. These scattered bones would then be trampled by other animals as they came to the into the area. The local habitat of the time would have been the same as it is today; wetland surrounded by open savanna and woodland. Such an environment would have supported a huge variety of herbivores including;
  • Harlan’s Ground Sloth (Paramylodon harlani)
  • Jefferson's Ground Sloth (Megalonyx jeffersoni)
  • Flat-headed Peccary (Platygonus compressus)
  • White-tailed Deer (Odocoileus virginianus)
  • Stag Moose (Cervalces scotti)
  • Caribou (Rangifer tarandus)
  • Moose (Alces alces)
  • Wapiti (Cervus canadensis)
  • Woodland Musk Ox (Bootherium bombifrons)
  • Antique Bison (Bison antiquus)
  • Wood Bison (Bison anthabascae)
  • Plains Bison (Bison bison)
  • Cope's Tapir (Tapirus copei)
  • Complex-toothed Horse (Equus complicatus)
  • American Mastodon (Mummut americanum)
  • Columbian Mammoth (Mammuthus columbi)

Wapiti grazed in the open fields alongside bison, horses,
and mammoths.
These herbivores, a mixture of grazers, browsers, and mixed feeders, all share a common need; all are highly water-dependent and must drink daily. None of the more dry-adapted herbivores like Pronghorn (Antilocapra americana), Mule Deer (Odocoileus hemionus), and Woolly Mammoth (Mammuthus primigenius) are found here, so rainfall must have been fairly high here. The wetland area provided a permanent water source for all these animals in addition to a source of vital minerals, and so the area would have seen much traffic by these species. 

With such an reliable and diverse prey selection this site would have also been a major hunting ground for several of America's large predators. The open woodland and savanna habitat was ideal for Lions (Panthera leo) and Gray Wolves (Canis lupus). The wetland area itself formed an ideal setting for ambush hunters like Saber-toothed Cats (Smilodon fatalis) and Dire Wolves (Canis dirus). Jaguars (Panthera onca), Cougars (Puma concolor), and Red Wolves (Canis rufus) would have favored the more wooded parts of this region. Omnivores like Brown Bears (Ursus arctos) and Black Bears (Ursus americanus) also inhabited these woodlands.

Red Wolves were among the several
wolf species that lived in the region.
Paleoenvironment (B- and A-horizons)
Directly above the C-horizon in -13,000 year old deposits we see an abrupt drop in megafauna diversity. This corresponds with the end-Pleistocene mass extinction. In these Holocene layers the only large herbivores present are extant species such as;

  • White-tailed Deer (Odocoileus virginianus)
  • Caribou (Rangifer tarandus)
  • Moose (Alces alces)
  • Wapiti (Cervus canadensis)
  • Wood Bison (Bison anthabascae)
After the extinction, the largest remaining predators are mid-sized hunters like the Cougar and the Red Wolf. The highly versatile Brown Bear and Black Bear also made it across the Holocene boundary. Perhaps as a result of the loss of large predators from the area, we see more evidence of human occupation in these upper layers mostly in the form of pottery shards. It is possible that while the large carnivores and other Pleistocene megafauna were still alive, certainly making the immediate vicinity a rather dangerous place, humans would have been more wary of the area and did not set up permanent encampments there.

References 
Lange, Ian M. "Ice Age Mammals of North America: A Guide to the Big, the Hairy, and the Bizzare". Missoula, Montana: Mountain Press Publishing Company, 2004. 81


Retrieved March 1, 2013 from http://www.uky.edu/KGS/fossils/quatern.htm

Photo Credits

  1. Woolly Mammoth model: Jerrye & Roye Klotz, 22 April 2012, Wikimedia Commons
  2. White-tailed Deer: Nicholas A. Tonelli, 3 June 2007, Johnsonburg Swamp Preserve, Wikimedia Commons
  3. Grazing Wapiti: Jon Sullivan, 21 June 2003, Wikipedia Commons
  4. Red Wolf: Steve Hillebrand, 22 July 2009, Wikimedia Commons

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