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Evidence of a Bison antiquus–size Cline on the Southern Plains Patrick J. Lewis, Eileen Johnson, Briggs Buchanan, and Leland Bement Editor’s Note: This paper was originally submitted for publication in 2003 (Vol. 20, pp. 103–105). At some point during the review and editing process, however, the text of this paper was inadvertently exchanged with that of an already published paper by the same authors. This earlier paper was published in 2001 (Vol. 19, pp. 108–110). Patrick J. Lewis, Department of Biological Sciences, Sam Houston State University, Huntsville, TX 77341; e-mail: [email protected] Eileen Johnson, Museum of Texas Tech University, MS 3191, Lubbock, TX 79409; e-mail: [email protected] Briggs Buchanan; Department of Anthropology, University of New Mexico, Albuquerque, NM 87131; e-mail: [email protected] Leland Bement, Oklahoma Archeological Survey, 111 E. Chesapeake, Norman, OK 73019; e-mail: [email protected]

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A north-to-south morphocline for late-Quaternary bison has been proposed by different researchers (McDonald 1981; Wilson, 1974), who suggest this morphocline extends from the modern species Bison bison (van Zyll de Jong 1986) into the past to late-Pleistocene Bison antiquus/occidentalis (McDonald 1981). Changing climates, small sample sizes, questionable dates, and widely dispersed samples associated with the bison, however, have made it difficult to determine the extent and magnitude of this size cline, particularly in regional detail. Research on size variation through the late Quaternary in bison metatarsals from the Lubbock Lake Landmark and Cooper sites on the Southern Plains, however, suggests that a north-to-south size cline may be detectable (Lewis et al. 2002). This research examines three Bison antiquus populations from the Southern Plains to determine size variation in the region at ca. 10,200 yr B.P./early Holocene. The bison populations are from Bonfire Shelter (10,230 yr B.P.) from southwestern Texas (Dibble and Lorrain 1968), the stratum 2 population from the Lubbock Lake Landmark (10,800–8600 yr B.P.) on the Southern High Plains (Johnson 1987), and Cooper (10,050 yr B.P.) from western Oklahoma (Bement 1997). Sample sizes are: Bonfire Shelter, n = 5; Lubbock Lake stratum 2, n = 19; Cooper, n = 13. These populations provide examples of ancient bison from the northern and southern extremes of the Southern Plains, as well as from a point between the two extremes. Metacarpals were used for this analysis due to large sample size, functional significance, and morphological conservatism. The use of metacarpals also tested the pattern found in the metatarsals in prior research (Lewis et al. 2002). Only length was used to examine size variation in the three populations. The sample was limited to males (Lewis et al. 2005) owing to the lack of intact metacarpals representing females in the Bonfire Shelter sample. Length was measured at the extremes using an osteometric measuring board. A boxplot was then generated, and data were tested with ANOVA for significant differences in size. The most southerly population, from Bonfire Shelter, was the smallest of the three populations examined, and the Cooper site population was the largest (Figure 1). Using an α of 0.05, the three sites were found to be significantly different (P = 0.05). A post-hoc pairwise ANOVA for the three

Figure 1. Male metacarpal lengths (cm) for the three ancient bison populations studied, with median, 75th percentiles, and 90th percentiles depicted (BF, Bonfire Shelter; LL2, Lubbock Lake stratum 2; CO, Cooper).

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sites showed this result to be due to the difference between Cooper and Bonfire Shelter (P = 0.02), but no combination of sites was significant when using the Bonferroni correction (Sokal and Rohlf 1995) for multiple tests (α = 0.017). This result underscores a size gradient among the three localities. Results indicate that a north-to-south size cline existed during the early Holocene on the Southern Plains. Significantly smaller bison were present at the southern edge of the Southern Plains, while increasingly larger bison were present farther north. Current research is expanding on these results to look at ancient bison of both sexes at several Southern Plains localities using a variety of measurements. Thanks are due to the VP Lab of the Texas Memorial Museum (Austin) for the loan of Lubbock Lake stratum 2 bison metacarpals recovered during the Evans and Meade explorations in the late 1940s to early 1950s and access to the bison remains from Bonfire Shelter. The additional Lubbock Lake stratum 2 bison metacarpals were collected under TAC permit #36 to the Museum of Texas Tech University (Lubbock). They are housed at the Museum of Texas Tech University and held-in-trust for the people of the State of Texas. The Cooper material is housed at the Oklahoma Archeological Survey (Norman). Research was funded by the Museum of Texas Tech University as part of the ongoing Lubbock Lake Landmark regional research program into late Quaternary climate and paleoecology of the Southern Plains.

References Cited Bement, L. C. 1997 The Cooper Site: A Stratified Folsom Kill in Oklahoma. In Southern Plains Bison Procurement and Utilization from Paleoindian to Historic, edited by L. C. Bement and K. J. Buehler. Plains Anthropologist 42(159):85–100 Dibble, D. S., and D. Lorrain 1968 Bonfire Shelter: A Stratified Bison Kill Site, Val Verde County, Texas. Texas Memorial Museum (Austin), Miscellaneous Papers, 1–138. Johnson, E. 1987 Lubbock Lake. Late Quaternary Studies on the Southern High Plains. Texas A&M Press, College Station, TX. Lewis, P. J., E. Johnson, B. Buchanan, L. Bement, and L. Gruss 2002 Size Variation in Southern Plains Bison antiquus from Lubbock Lake and Cooper. Current Research in the Pleistocene 20:108–10. Lewis, P. J., B. Buchanan, and E. Johnson 2005 A New Multivariate Approach to Sexing Bison Metapodials. Plains Anthropologist 50(194):159–72. McDonald, J. N. 1981 North American Bison. Their Classification and Evolution. University of California Press, Berkeley, CA. Sokal, R. R., and F. J. Rohlf

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Biometrics. W. H. Freeman and Company, New York, NY.

van Zyll de Jong, C. G. 1986 A Systematic Study of the Recent Bison, with Particular Consideration of the Wood Bison (Bison bison athabascae Rhoades, 1898). National Museum of Canada, Publications in Natural Sciences, 6:1–69. Wilson, M. V. 1974 The Casper Local Fauna and its Fossil Bison. In The Casper Site. A Hell Gap Bison Kill on the High Plains edited by G.C. Frison, pp. 125–71. Academic Press, New York, NY.