The taphonomic record of Upper Siwalik (Pinjor stage) landscapes in the Pabbi Hills, northern Pakistan, with consideration regarding the preservation of hominin remains

The Pabbi Hills contain a Late Pliocene and Early Pleistocene sequence that was extensively surveyed for fossil remains. Ca. 40,000 specimens from an estimated 1000 individual animals were collected from three types of fossil occurrences (N=445). Twenty fossil accumulations produced ca. 50% of all fossils found, and over half of all fossil occurrences contained <25 specimens. The largest fossil concentrations were found in silts and fine sands in abandoned and shallow stream channels, and the main agents of fossil accumulation were large predators and streams. The fauna was dominated by herbivores (particularly bovids) >100 kg adult body size. Although buried fossils were generally well preserved, much information was lost after re-exposure by fragmentation and sub-aerial weathering. Comparisons with Miocene Siwalik faunas and environments indicate considerable loss of habitat diversity, fewer types of herbivores, increased herbivore body size and an increased role of predators (notably Pachycrocuta) as accumulating agents. The absence of hominin remains can be attributed to biases towards the preservation of larger animals, the effects of fragmentation and the absence or rarity of stone suitable for making stone tools.