New Oldowan locality Sare-Abururu (ca. 1.7 Ma) provides evidence of diverse hominin behaviors on the Homa Peninsula, Kenya.

The Homa Peninsula, in southwestern Kenya, continues to yield insights into Oldowan hominin landscape behaviors. The Late Pliocene locality of Nyayanga (∼3-2.6 Ma) preserves some of the oldest Oldowan tools. At the Early Pleistocene locality of Kanjera South (∼2 Ma) toolmakers procured a diversity of raw materials from over 10 km away and strategically reduced them in a grassland-dominated ecosystem. Here, we report findings from Sare-Abururu, a younger (∼1.7 Ma) Oldowan locality approximately 12 km southeast of Kanjera South and 18 km east of Nyayanga. Sare-Abururu has yielded 1754 artifacts in relatively undisturbed low-energy silts and sands. Stable isotopic analysis of pedogenic carbonates suggests that hominin activities were carried out in a grassland-dominated setting with similar vegetation structure as documented at Kanjera South. The composition of a nearby paleo-conglomerate indicates that high-quality stone raw materials were locally abundant. Toolmakers at Sare-Abururu produced angular fragments from quartz pebbles, representing a considerable contrast to the strategies used to reduce high quality raw materials at Kanjera South. Although lithic reduction at Sare-Abururu was technologically simple, toolmakers proficiently produced cutting edges, made few mistakes and exhibited a mastery of platform management, demonstrating that expedient technical strategies do not necessarily indicate a lack of skill or suitable raw materials. Lithic procurement and reduction patterns on the Homa Peninsula appear to reflect variation in local resource contexts rather than large-scale evolutionary changes in mobility, energy budget, or toolmaker cognition.

Searching for the earliest archaeological record: insights from chimpanzee material landscapes.

The origin of tool use is a central question in human evolutionary studies. Plio-Pleistocene core and flake technologies represent the earliest evidence of tool use in the human lineage. Some suggest this form of tool use is probably pre-dated by a phase of percussive tool use. However, there is currently no evidence for such a record. The archaeological signature of solely percussive behaviours is not as well understood as that associated with cores and flakes. The durable nature of primate percussive stone tools and their by-products provide an opportunity to investigate what such a record looks like. Here, we present a landscape-scale study of the chimpanzee (Pan troglodytes verus) material culture from the Djouroutou Chimpanzee Project, Taï Forest, Cote d'Ivoire. This study explores the interplay between behavioural and environmental factors in shaping the stone record of nut cracking. Through a survey of nut-cracking sites, the available nut species, and raw materials, we show how resource availability influences the resulting material signature of nut cracking. These results also reveal the diversity of material signatures associated with a purely percussive material record. We gain insight into the range of signatures that may be associated with a pre-core and flake archaeological record, providing new expectations for an earlier record of tool use.