Taphonomic insights into fossil preservation and accumulation of Pleistocene Pongo ‐bearing assemblages from Tham Khao Phak Kut in Krabi, Peninsular Thailand

ABSTRACT This paper presents the first systematic taphonomic study of cave deposits from the newly discovered fossil site of Tham Khao Phak Kut cave (TKPK), Ao Luek District, Krabi Province in Peninsular Thailand. Two fossil‐bearing loci (TKPK 1 and TKPK 2) have yielded moderate accumulations of isolated teeth and bone fragments from small to large‐sized animals, preserved in sedimentary remnants on cave walls and ceilings. The two diverse Pleistocene vertebrate assemblages include chiropterans, primates, rodents, carnivorans, proboscideans, perissodactyls, artiodactyls, and birds, mostly analogous to extant rainforest‐associated faunas of Peninsular Thailand, except for three locally extinct taxa: Pongo sp., Hystrix indica , and Naemorhedus goral . The large mammal faunas of both loci suggest a Middle to Late Pleistocene age, as compared with those from other dated sites. At least two primary taphonomic pathways are inferred: a prime‐aged dominated macrofauna component initially produced by natural accumulation but subsequently gnawed by porcupines, scavenged by carrion beetles and transported to the cave by low‐energy water action over a short distance, and a microfauna component likely accumulated by small carnivores, both ultimately buried by colluvial flow. This study represents the first record of orangutan fossils in Peninsular Thailand and offers key insights for future chronological and palaeoenvironmental studies of Pleistocene Pongo ‐associated faunas in mainland Southeast Asia.