At the more local level, patterns of distribution of the non-diadromous species in the fauna relate to a long series of events that relate to New Zealand’s geological and climatic history: beginning with New Zealand’s substantial, some think complete, marine submergence in the Oligocene; deposition of fossils in Miocene lakes of Central Otago; the implications of the Alpine Fault, submergence of the southern North Island in the Pliocene; widespread Miocene to Recent volcanism; a series of localised river catchment changes in diverse river systems; Pleistocene glaciation; and the presence of species on the distant Chatham, Auckland and Campbell Islands to the east and south of mainland New Zealand. Speciation processes and distribution patterns were influenced by all of these processes and events.