The tropical to temperate continental margin of Western Australia (WA), where recent CSIRO collections (100- 1000 m) revealed over 800 nominal species of decapod crustaceans, thirty per cent of which are thought to be new to science. Squat lobsters of the family Galatheidae, one of the most numerous and diverse groups of crustaceans commonly encountered on seamounts, continental margins and shelf habitats at all depths. Galathean species exhibit high morphological diversity, believed to be the result of a relatively old radiation event. Yet, their origins, phylogenetic and phylogeographic relationships are not entirely clear. Squat lobsters constitute an exceptional model system for evaluating historical processes responsible for at the present observed distribution patterns of the Western Australian fauna