Studies on Middle and Late Pleistocene hominin dietary adaptations have argued that aquatic foods played a key role during this evolutionary process. This chapter presents a summary account on the use and significance of marine resources, particularly shellfish, for early modern humans in southern Africa during oxygen isotope stages (OIS) 6–4. The methods used to identify, quantify, and compare archaeomalacological assemblages in South Africa and beyond, their drawbacks, as well as palaeoenvironmental, taphonomical and foraging considerations necessary to evaluate these data are discussed. The significance of diet broadening in the context of emerging modern humans about 160 ka and their exit out of Africa ~80–60 ka is reflected upon in the light of coastal adaptations by other early hominins groups elsewhere, such as Neanderthals in the Mediterranean Basin. The implications of longer residential permanence and higher population densities generally possible near productive shorelines are also examined.