AbstractSize sorting of shells and valves of transported death assemblages ofMytilus edulisis shown to have taken place, and greatly affected size‐frequency distributions of shell accumulations deposited in a beach environment. Selective transport and deposition of different size grades gives histograms which may be strongly skewed or multimodal, and include numerous small shells. The usually predicted bell‐shaped distributions for sorted assemblages are not always produced. Little evidence of growth and mortality rates can be deduced with confidence from the transported assembla