Bone Preservation, Specimen Identifiability, and Outcrop Shape – A Preliminary Investigation of Early Pleistocene Taphonomy at Koobi Fora, Kenya

Summary

Fossil bone surface assemblages include differential specimen preservation (weathering stage, cortical surface exfoliation, polish, roundedness, fracture type) and identifiability (taxonomic or anatomical precision). Three 1x1 meter inventory squares placed on steep, moderate, and minimally sloping areas of a fossiliferous outcrop test whether outcrop shape is a megabias that influences assemblage attributes. A digital elevation model created from drone-captured aerial imagery describes outcrop slope, erosional potential, and pooling potential for each inventory square. In general, erosional potential increases with outcrop slope and pooling potential increases in flatter areas, but these attributes do not covary perfectly in our squares. We analyzed all (between 21 and 40) specimens per square, and observed that median specimen size, the distribution of specimen weathering stage, fracture type, roundedness, and precise anatomical identifiability were not related to outcrop slope. The flattest square was overrepresented in abraded and taxonomically identifiable specimens (superfamily or finer). The steepest square was overrepresented in exfoliated specimens. The moderately sloping square was underrepresented in exfoliated, abraded, and precisely identified taxonomic specimens. These results suggest that outcrop shape is not a megabias that uniformly impacts assemblage formation, and that the complex relationship underlying fossil preservation, specimen identifiability, and outcrop shape warrants further attention.

This Resource is Part of the Following Collections

• Society for American Archaeology 83rd Annual Meeting, Washington, DC (2018)

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Record Identifiers

Abstract Id(s): 22566