The relationship of weathering cracks to split‐line orientation in bone

Abstract The essential identity of weathering cracks and split‐lines is demonstrated experimentally. Innominate bones, left in the open to weather, developed cracks similar to the split‐line orientation typically observed in the same region. These bones were decalcified and intermittent split‐lines prepared along their course. The orientation of the split‐lines always corresponds to the weathering splits. The same results were obtained with bird and mammal bones collected in the field and showing weathering cracks. The same also applies to cracks in bones of a gorilla which had been partly defleshed and salted down for preservation. Apparently any process which shrinks bone will produce cracks with the same orientation as split‐lines. Possibilities for split‐line analysis of fossil and archeological bone are opened up by these experiments.