Paläobiogeographische Analyse der tertiären Fischfauna von Neuseeland und Süd-Australien

Faunistic movements of bony fishes are investigated during the Tertiary of the Australian/New Zealandian region and are interpreted in respect to the disconnection of Australia and Antarctica and the initiation and development of the circumantarctic current. In early Eocene the New Zealandian fauna (tethyal origin) is principally different from the South Australian one (? southern Atlantic origin). In uppermost Eocene a break through of the Tasman Passage allows a first invasion of New Zealandian sublittoral fishes into the Great Australian Bight. Since Middle Oligocene these New Zealandian/ Indopacific sublittoral elements almost completely replace the original South Australian fauna and initiate an endemic evolution in this area. Faunistic exchange of deep sea fishes can be observed with some time delay since at least Middle Oligocene following the eastwards directed circumantarctic current. At the same time we realize a first invasion of mesopelagic fishes of northern Atlantic affinities to New Zealand. Simultaneously, a climax is evident for the development of the endemic sublittoral New Zealandian fauna. All these facts, mainly observed in south-east New Zealand, lead to the postulation of a colder current side branching from the circumantarctic current and running northwards along the south-eastern coast of New Zealand. The evolution of the relatively uniform Southern Ocean meso- and bathypelagic fauna is discussed as a function of the developement of the southern temperate climatic zone and the initiation of the circumantarctic current. Faunistic elements of these affinities are recognizeable since at least Lower Miocene. A number of selected ichthyological data, recent and fossil, are presented on biogeographic maps.