Paleoindian tool from a horse tibia
By Dr. S. David Webb and James S. Dunbar
In our recent chapter entitled “Bone and Ivory Tools from submerged Paleoindian Sites in Florida” Jim Dunbar and I de-scribed, figured, and interpreted a number of Paleoindian tools. Since most Paleoindian sites yield only lithic tools, most of these items were either rare or unique. Some items were comparable to tools known only from Old World Paleolithic sites. The one item that strikes me as most unusual is made from a horse tibia. This is one of the very few pieces of evidence in all of North America that demonstrates that Paleoindians utilized the horse. This does not prove that humans butchered the horse, but it certainly indicates that they knew the animal well enough to utilize freshly recovered parts of its skeleton. Furthermore there is strong evidence of prior knowledge in the Old World. The ancestors of these Paleoindians knew Equus intimately, rendering its likeness exquisitely on cave walls, and New World peoples continually encountered horses as their range extended into Florida. For this reason the tibia described here seems to close the circle of evidence that late Pleistocene people continued to track and use the horse as they entered the New World. The tibia is a stout, triangular element from the lower part of the hind limb. Its distal articular end feels good in the grip of one’s hand. We are pleased to place this important piece from late Pleistocene sediments in the Waccasassa River on record.
Equus left tibia
Site and context: This specimen was recovered from 2 meters of water in the Waccasassa River, locality 9, Levy County, Florida. Collected by Robert Armistead and donated to the Florida Museum of Natural History in 1966, it was associated with abundant Late Pleistocene megafauna.
Description of specimen: Specimen UF 16822 (Fig. 1) represents the distal half of a mature left tibia of a medium-sized Equus (horse) species. It is nearly black, strongly mineralized, and quite dense. Its overall length is about 140 millimeters, with the break at about the narrowest part of the bone near the middle of its shaft. Two large chips of bone were broken from the lateral side of the shaft; these breakage scars, one about 80 millimeters and the other about 60 millimeters long, are coarse and occurred as brittle breaks after the bone had become fossilized.
The most interesting features of the tibia occur near the midshaft break, where the natural diameter of the shaft narrowed to about 40 x 30 millimeters. That area is dominated by a set of at least two dozen conchoidal flake scars, each about 10 millimeters long and directed from the broken end of the tibia. The major removal scars were modified by innumerable smaller pecks. All of these features evidently were produced while the bone was still fresh. One must conclude therefore that the midshaft break that they modified also took place while the tibia was green. The effect of this elaborate flaking and pecking was to produce a gently roughened and beveled zone extending 30 to 40 millimeters toward the narrowest part of the tibia (top of Fig. 1).
Other interesting features appear inside the marrow cavity of this tibia. That cavity was smoothed and somewhat enlarged toward the beveled end of the specimen. Its maximum cross section is ovate with a mediolateral diameter of 14.1 millimeters and a transverse diameter of 10.2 millimeters. About 54 millimeters toward the distal (intact) end of the tibia, the marrow cavity ends as a smooth pocket.
At its distal end, the tibia is nearly 70 millimeters wide and made of very dense bone. It was nearly twice as wide as the midshaft area. A number of fine striations at various oblique and transverse angles occupy the anterior and posterior faces of the tibia in a middle zone between the beveled region and the distal expansion of the tibia. Presumably, these were scratches acquired incidentally during use of this Equus tibia tool.
Comparison: A number of researchers have recovered prehistoric flaked bone specimens. Some subsequently conducted bone-knapping experiments in order to replicate raw bone manipulation (e.g., Morlan and Cinq-Mars 1982; Stanford et al. 1981). The oldest previous example of a Florida flaked bone tool is an awl-and-scraper combination from an Early Archaic stratum (about 10,000 years old) at Warm Mineral Springs (Cockrell and Murphy 1978). Socketed antler handles of Early Archaic age were recovered from that spring and also from numerous rivers, including sites in the Ichetucknee, Aucilla, and Santa Fe rivers. Such examples show that the use of knapped and socketed bones (and antlers) as handles was well established by the Early Archaic in Florida. We now offer older but similar evidence from an extinct Equus tibia. Evidently, the broad tradition of fashioning socketed handles from heavy bones had Paleoindian roots.
Proposed function: When one grasps the tibia by the broad and dense distal end, it is immediately evident that it provides an excellent handle, which could be grasped in the center of the palm and surrounded by all five fingers. The elaborately beveled surface surrounding an enlarged marrow cavity must be for holding some additional part of the tool, possibly an awl, probe, or dagger.