Percorrer por autor "Key, Alastair"
A mostrar 1 - 3 de 3
Resultados por página
Opções de ordenação
- Hominin glacial-stage occupation 712,000 to 424,000 years ago at Fordwich Pit, Old Park (Canterbury, UK)Publication . Key, Alastair; Clark, James; Lauer, Tobias; Bates, Jennifer; Sier, Mark-Jan; Nichols, Claire; Martín-Ramos, Carmen; Cebeiro, Adela; Williams, Eleanor; Kim, Sunghui; Stileman, Finn; Mika, Anna; Pope, Matthew; Bridgland, David; Redhouse, David; Leonardi, Michela; Smith, Geoff M.; Proffitt, TomosFew high-latitude archaeological contexts are older than marine isotope stage (MIS) 15 and even fewer provide evidence of early human occupation during a glacial period. New discoveries at Old Park, Canterbury (UK), provide evidence of both the oldest accessible artefact-bearing sediment in northern Europe and cold-stage adaptation. Radiometric and palaeomagnetic dating places the earliest suggested occupation of this site between 773 thousand years ago (ka) and 607 ka, with hominin presence inferred during MIS 17–16. Two additional artefact-bearing stratigraphic units, dated to around 542 ka and 437 ka, strongly align with the MIS 14 and 12 cold stages, respectively. The latter unit contains convincing evidence of glacial-stage occupation by Acheulean hominins; fresh, unabraded flakes (including biface-thinning) between clearly defined glacial-aged sediments displaying mixed grassland palaeoenvironmental evidence. An historically collected assemblage of more than 330 handaxes is argued to be derived from both the MIS 17–16 and MIS 12 sediments, providing evidence of the earliest known Acheulean bifaces in northern Europe, and re-occupation by Acheulean populations 200,000 years later. Together, Old Park provides evidence for Lower Palaeolithic hominins reoccupying a location over several mid-Pleistocene MIS cycles, early human presence above 51° latitude during a glacial stage and handaxe production in northern Europe from MIS 17 to 16.
- Identifying accurate artefact morphological ranges using optimal linear estimation: method validation, case studies, and codePublication . Key, Alastair; Eren, Metin I.; Bebber, Michelle R.; Buchanan, Briggs; Cortell-Nicolau, Alfredo; Martín-Ramos, Carmen; Peña, Paloma de la; Petrie, Cameron A.; Proffitt, Tomos; Robb, John; Michelaki, Konstantina-Eleni; Jarić, IvanA fundamental goal of archaeologists is to infer the behaviour of past humans from the attributes of the artefacts they left behind. The archaeological record is, however, fragmented and often provides a partial record of the total artefacts produced by a given population. In turn, there is potential for population-level morphometric data, and therefore behavioural inferences, to be biased relative to the trends realised in the past. This includes morphological range data which are important for identifying similarities and differences between artefact groups, and for contextualising artefacts relative to external variables such as human anatomy, ecology, climate and chronology. Here, we investigate whether optimal linear estimation (OLE) modelling can be used to accurately identify the upper and lower limits of artefact morphological ranges (including those represented by sparse datasets). First, we test whether OLE reliably identifies morphological ranges using randomly sampled subsets of ‘known and complete’ replica artefact assemblages. Using morphometric data from lithic, ceramic, and metal archaeological case studies, we then identify how much further the upper and lower form limits of these artefact types would have been in the past, relative to the ranges evidenced by excavated (i.e., known partial) records. Validation tests demonstrate OLE to be capable of providing broadly accurate estimates for the true morpho logical range of artefact assemblages. Estimate accuracy increases relative to the percentage of the total assemblage used and the method is shown to function well using as few as five records (k) from an assemblage. The case studies reveal how OLE can overhaul or reinforce our understanding of artefact morphological ranges. In some instances, it is clear that the archaeological record provides a highly accurate representation of artefact morphological ranges and the overlap between artefact groups. For others, it is demonstrated that our understanding of the extreme artefact forms produced by past people is likely inaccurate
- Revising the oldest oldowan: updated optimal linear estimation models and the impact of Nyayanga (Kenya)Publication . Key, Alastair; Proffitt, TomosThe Oldowan lithic industry represents the earliest known evidence of efficiently and expeditiously produced flake stone tools (Toth, 1985; Braun et al., 2019; Reti, 2016; Stout et al., 2019). Complex technological strategies were employed to produce these artefacts compared to earlier hominin stone tools, and potential organic tool-use behaviors inferred via parsimony with non-human primates (Braun et al., 2019; Boesch et al., 2020; Delagnes and Roche, 2005; Gürbüz and Lycett, 2021; Harmand et al., 2015; Lombard et al., 2018; Plummer et al., 2023; Proffitt et al., 2023a, 2023b; Stout et al., 2010; Toth and Schick, 2009). Consequently, the emergence of the Oldowan can still (cf. Leakey, 1971) be argued to reflect a behavioral and evolutionary shift within the hominin lineage, although the nature and species-associations of any changes have become less clear in recent years (Bobe and Wood, 2021; Braun et al., 2019; Hovers, 2012; Lewis and Harmand, 2016; Plummer et al., 2023). Nyayanga, located in the Homa Peninsula of Kenya, has recently emerged as an important archaeological and paleontological site yielding evidence of Oldowan stone tools and butchered fauna dating to between 2.595 and 3.032 Ma (Plummer et al., 2023). These findings not only represent the earliest currently known occurrences of the Oldowan but also greatly expand our understanding of its early geographic distribution. Further, some lithics at Nyayanga were found alongside Paranthropus molars, challenging prevailing assumptions regarding Oldowan species-associations and providing a rare instance of Early Stone Age (ESA) hominin fossil and lithic remains in close association. The co-occurrence of cut marked fauna and flakes, including those excavated in direct contact with hippopotamid remains, further distin guishes Nyayanga as an exceptional ESA occurrence extending hominin dietary and technological behaviors “similar to other Oldowan assem blages” into the Pliocene (Plummer et al., 2023: 563).