S15-8

The Taphonomy of Small Mammals from Callao Cave (ca. 67 ky BP to 3.6 ky cal. BP): Methods and Preliminary Assessment

Patricia Cabrera1, Juan C. Rofes1, Janine Ochoa2, Lawrence R. Heaney3, Armand Salvador B. Mijares1

1Archaeological Studies Program, University of the Philippines, Philippines

2Department of Anthropology, University of the Philippines, Philippines

3Field Museum of Natural History, U.S.A.

Evidence for early humans from the Late Pleistocene (~67 ky BP and ~28 ky cal. BP) until the Holocene (~3.6 ky cal. BP) have been identified in Callao Cave in northern Luzon, Philippines. This includes the extinct Homo luzonensis from the Late Pleistocene along with some of the earliest known fossils of extinct endemic Philippine murids (Batomys cagayanensis, Carpomys dakal, and Crateromys ballik), highlighting the potential of the site for understanding human evolution and past biodiversity. A prerequisite for such an investigation is the study of site formation processes. The excavation of Callao Cave in 2020 sought to examine the depositional history of the cave, and this ongoing research on small mammals serves as an important proxy to reconstruct site formation processes at work in the cave. Small mammals are recognised as excellent indicators of human activities and past environments. However, because of their diminutive size, specific methods must be used to ascertain that their taphonomic histories securely place them in the contexts researchers are most interested in. In this presentation, the methods that will be used to investigate small mammal taphonomy at Callao Cave will be discussed. More than 74,000 small vertebrate remains were recovered from throughout the Holocene and Late Pleistocene archaeological sequences using an intensive recovery method designed for small vertebrates. Approximately 20% (N=14,829) of the remains have been sorted taxonomically, and within this sub-sample, around 52% (N=7,723) have been identified as mammals. Three main variables will be examined to account for differences in accumulating processes and agents: surface modifications, anatomical representation, and breakage patterns. The taphonomic pathways of the assemblage, combined with the geomorphological attributes of the cave, will then be used to identify and evaluate taphonomic impacts on the small mammal assemblages.