Acknowledgments and References OSTEOLOGY AND GEOLOGY OF AN ICE AGE FOSSIL FROM IDAHO: THE BELLOWS-FRUITLAND MAMMOTH COX, Tami, Anthropology, Boise State University, 1910 University Drive, Boise, ID, 83725, and HILL, Christopher L., Anthropology and Environmental Studies, Boise State University, 1910 University Drive, Boise, ID 83725, chill2@boisestate.edu Introduction Fossil Assemblage Other bones in the fossil assemblage include the right and front forfeet, a partial pelvis, 11 vertabrae, ribs, and a stylohoid . The sediments at the gravel pit are at the same elevation as the Wilder terrace which may correlate with the Sunrise terrace or be intermediate between the Gowen and Sunrise terraces in the eastern Boise Valley. If these correlations are valid, the mammoth fossils may be middle Pleistocene in age. The Sunrise terrace is correlated with OIS 8, while the Gowen terrace is correlated with OIS 12 and 14 (Othberg et al. 1996). In 2008, a set of fossil bones were found in a gravel pit near Fruitland, in southwestern Idaho. Here we summarize the results of osteological studies of the bones and the geologic context in which they were discovered. Mammoth fossils can provide information about a specific, individual animal as well as contribute to a greater understanding of anatomical variability in extinct populations. Geologic studies of the deposits containing the fossils can be used to infer local Pleistocene environmental conditions and taphonomic processes. The fossil assemblage consists of two molars and parts of the mandible, tusk fragments, and post-cranial elements. The dentition is indicates the specimen can be taxonomically identified as a Columbian mammoth (Mammuthus columbi). The 6 tusk fragments range in length from 20.0 to 110.5 cm. Based on the criteria developed by Laws (1966) and Jachmann (1988) the molars provide an estimated age of between 18-39 years. Long bones include: left and right humeri; left and right ulnae/radiae; right femur; right tibia; and right fibula. From: Othberg et al. 1996 The locality is east of the Snake River. The gravel pit is situated in the Nyssa 7.5 minute quadrangle at an elevation of about 725 m a.s.l., in an upland area between Ashlock Gulch (also called Big Whitney Gulch) to the south and Hurd Gulch to the north. Summary The Bellows-Fruitland Mammoth was recovered from fluvial deposits that may date to the middle Pleistocne (~250-575 ka). The fossil assemblage (shown in blue below) could be the remains of a young adult female mammoth. Geologic Context The stratigraphic exposure where the fossils were discovered is an 8-m-thick sequence of fluvial sands and gravels. The sediments enclosing the bones were indurated and consist mostly of cross-bedded medium sands with coarse sand and gravel, and low amounts of finer clastics. Glacier Peak Based on the length of the humerus, the height at the shoulder can be calculated (Harrington et al. 1974). Since the length of the humerus is 88 cm, the height of the mammoth at the shoulder is estimated to be between 280-300 cm, suggesting the possibility that the animal may have been a small female. Ribs embedded in well sorted sands. View of the gravel pit containing mammoth fossils, looking south. General view of sedimentary deposits at the gravel pit. Meter scale (circled in yellow) is on the surface where the fossils were found. Acknowledgments and References 88 cm We are especially grateful to Duane Bellows for permission to study the fossils and their geologic context. Stephanie Bellows and Duane Bellows collected most of the fossils. Their wishes to use the discovery for educational purposes have made this study possible. Harrington, C.R., Tipper, H.W. and Mott, R.J. 1974. Mammoth from Babine Lake, British Columbia. Canadian Journal of Earth Sciences 11(2): 285-303. Jachman, H. 1988. Estimating the age in African elephants: a revision of Laws’ molar evaluation technique. African Journal of Ecology 26: 51-56. Laws, R.M. 1966. Age criteria for the Africam elephant, Loxodonta, a. Africa, East African Wildlife Journal 4: 1-37. Othberg, K.L., O’Connor, J.E. and McDaniel, P.A. 1996. Field Guide to the Geology of the Boise Valley. Idaho Geological Survey Staff Report 96-1, Moscow. Tusk embedded in gravels.