The Makapansgat Limeworks grey breccia: hominids, hyaenas, hystricids or hillwash?
Maguire, J. M.
Collett, M. H.
Bernard Price Institute for Palaeontological Research
The question of the origin of the Makapansgat Limeworks grey breccia is here considered from two viewpoints: (a) the accumulation of bones within a catchment area; and (b) the possible concentration of the bones in their final resting place. The potential role of hyaenas and porcupines as bone-accumulating agents is investigated. Nine categories of hyaena damage to bone surfaces could be distinguished on collections of bone taken from a series of recent hyaena breeding dens. All nine categories can be demonstrated in identical form on fossil bones from the grey breccia. It is concluded that carnivores have played a more substantial role as accumulators of the bones in this breccia than has previously been acknowledged. Porcupines are excluded as major contributors to the grey breccia bone assemblage on the basis of the low percentage of porcupine-gnawed bones present compared with recent porcupine accumulations. Furthermore, the pattern of damage observed on porcupine-collected skeletal elements does not resemble that documented for the grey breccia. A 3-dimensional computer plot of the topography of the Limeworks travertine floor shows the presence of two larger and two smaller basins separated from each other by floor "highs". A floor "high" around the grey breccia is demonstrated and may have been a significant factor in bone concentration. Sedimentation within separate basins need -not necessarily have been synchronous or equivalent, and the practice of equating Members from one part of the cavern to another is questioned. Stereographic projections of the dip and strike orientations of the long axes of a number of in situ grey breccia bones in two separate areas indicate orientation patterns and imbrication. The results of the projections suggest that a combination of water current action and gravity may have been responsible for the present configuration of the bones.
Makapansgat; Limeworks; breccia; hominids; hyaena; hystricid; hillwash