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By Christopher Jurgens, Ph.D.
The Center for Archaeological Studies (CAS) 2014 excavations at the Spring Lake Site (41HY160) recovered more than 6,000 fragments of animal bone. Detailed analysis of the bone, often termed faunal analysis, began in the summer of 2016. Faunal analysis is part of a specialty in archaeology that is known as zooarchaeology (Reitz and Wing 2008). The bone fragments were analyzed to identify the animals represented and human modification from subsistence or bone technology activities. Procedures began with sorting into groups based on size of animal, signs of burning, or obvious evidence of butchering, skinning, or technological modification (Figure 1).
Fragments of animal bone recovered from the Spring Lake Site are small and in poor physical condition. The faunal analysis required techniques I’ve used over the past 20 years (Figures 2 and 3). Special lighting includes an overhead general light and a low sidelight that increases contrast. The sidelight reveals changes to the bone surface. Carnivore damage and root-etching modify the bone surface. Butchering damage and technological modifications made during tool or ornament manufacture and use each leave distinctive traces on the surface of bone.
Many small fragments were identifiable as skeletal elements from specific animals, often to genera or species used in biological classification. With standard zooarchaeological procedures, skeletal materials from reference specimens of fish, birds, and mammals were used to identify the faunal material. Some of the reference specimens were loaned from the Vertebrate Paleontology Laboratory at the University of Texas at Austin. Deer and bison reference specimens belonging to CAS were also used. Fish and squirrel specimens came from my own reference collection (Figures 4 – 7). Historical records of fish documented in the region by Kenneth Jurgens (1951) were also used in determining what species might be identified during the analysis, as well as other published references containing detailed anatomical drawings (Figure 8).
Many fragments showed signs of butchering or cooking by the site’s inhabitants. Skinning and butchering leave distinctive cutmarks. Direct heat cooking, such as grilling or roasting, leaves distinctive discoloration of bone fragments. Some fragments were completely discolored by heat from inclusion in the soil surrounding earth ovens used to bake plants. Other fragments were incinerated by heat over 850o F that removed most organic material from the bone.
Some fragments retained signs of specific modification made during manufacture and use of bone tools and ornaments. Bone tools often exhibit scrape marks made to remove the periosteum layer from the bone surface; distinctive grooves cut to allow controlled snapping of the bone into segments; grinding of edges; and wear left by contact with plant materials, hides, or other substances when used by the site’s inhabitants. Incised bone artifacts and bone beads represent ancient artistic expression and allow us to study behavior beyond subsistence (Figure 9).
Assignment of bone fragments to the most appropriate taxonomic group requires an understanding of bone structure and skeletal anatomy of all potential animal groups, from fish and reptiles to birds and mammals. Some of the bones are easy to identify, based on their structure and morphology (Figure 10 and Figure 11). Distinctive features allow identification of bone fragments to specific animal form and skeletal element.
Cultural modification of animal bone fragments by the Spring Lake Site’s prehistoric residents was obvious (Figures 12 – 16). Figures 12 and 13 revealed signs of bone breakage to remove marrow from leg bones of deer or antelope.
One bone tool fragment (Figure 14) shows clear signs of grooving and snapping used to detach bone tool blanks from large mammal long bones during manufacture. The irregular edges remaining from blank detachment may indicate that the tool was broken before being completed.
The same process was used to make both formal and informal tools. Figure 15 shows an informal hide-working tool fragment that retains grooving, but also helical fracturing. Figure 16 is part of a formal tool used in processing silica-rich plants.
Much of my recent research has focused on fauna from sites in the Lower Pecos region of West Texas (Castaneda, et al. 2016; Jurgens 2005a, 2005b, 2006, 2008, 2014a, 2014b, 2015; Jurgens and Rush 2015). During the Spring Lake Data Recovery Project faunal analysis, I’ve noticed many similarities to the Lower Pecos study results. Bone tool or ornament fragments, and evidence for their manufacture, have rarely been documented in Central Texas. Analysis of the Spring Lake faunal material is showing us that the same processes used to make the tools and ornaments in the Lower Pecos were in use in Central Texas by the Early Archaic. Sites such as Spring Lake help us open the doors onto the past to understand how widespread cultural processes, such as bone technology, were prevalent in prehistory.
Castañeda, Amanda M., Christopher Jurgens, Charles W. Koenig, Stephen L. Black, J. Kevin Hanselka, and Haley Rush
2016 “Multidisciplinary Investigations of a Paleoindian Bison Butchery Event in Eagle Cave.” Paper presented at the 87th Texas Archeological Society Annual Meeting. Nacogdoches, Texas.
Jurgens, Christopher J.
2005a “Zooarcheology and Bone Technology from Arenosa Shelter (41VV99), Lower Pecos Region, Texas.” (http://repositories.lib.utexas.edu/handle/2152/1586). Unpublished Ph.D. Dissertation. Department of Anthropology. The University of Texas at Austin.
2005b “An Overview of the Zooarchaeology and Bone Technology from Arenosa Shelter (41VV99) in the Lower Pecos Region.” Paper presented at the 76th Texas Archeological Society Annual Meeting. Austin, Texas.
2006 “The Fish Fauna from Arenosa Shelter (41VV99), Lower Pecos Cultural Region, Texas.” Paper Presented in the Symposium Honoring Oscar J. Polaco and His Contributions to Latin American Zooarchaeology, Sponsored by the Fryxell Committee, Society for American Archaeology, 71st Annual Meeting, San Juan, Puerto Rico.
2008 “The Fish Fauna from Arenosa Shelter (41VV99), Lower Pecos Cultural Region, Texas.” In: Joaquín Arroyo-Cabrales and Eileen Johnson, Guest Editors, Contributions to Latin American Zooarchaeology in Honour of Oscar J. Polaco, Fryxell Award Recipient for Interdisciplinary Research. Quaternary International 185:26-33.
2014a “Preliminary Results from Zooarchaeological Analysis of Eagle Nest Canyon Sites.” Paper presented at the 85th Texas Archeological Society Annual Meeting. San Marcos, Texas.
2014b “Cutting It in the Lower Pecos.” Guest lecture to Anthropology 689-602 (Ancient Foodways and Cooking Technologies Graduate Seminar), Texas A&M University. College Station, Texas.
2015 “Lower Pecos Faunal Recovery, Sampling, and Analysis Issues.” Guest Lecture to Anthropology 4630 (Archaeological Field School), Texas State University. Shumla, Texas.
Jurgens, Christopher J., and Haley E. Rush
2015 “Extending Arenosa Shelter’s Reach: Zooarchaeological Research in Eagle Nest Canyon 2015.” Poster Presented at the 86th Texas Archeological Society Annual Meeting. Houston, Texas.
Jurgens, Kenneth C.
1951 “The Distribution and Ecology of the Fishes of the San Marcos River.” Unpublished M.A. Thesis. Department of Zoology. The University of Texas. Austin, Texas.
Reitz, Elizabeth J. and Elizabeth S. Wing
2008 Zooarchaeology (Second Edition). Cambridge Manuals in Archaeology. Cambridge University Press, Cambridge, U.K.