Searching for ancestral areas and artifactual centers of origin in biogeography: with comment on east-west patterns across Southern Australia.

Cover Illustration: The cover pictures an Eocene Atlantogean landscape showing vertebrate groups shared only by South America and northern Africa during the Tertiary. The basis is a palaeoprovince proposed by Ezcurra and Agnolin (this issue) that included South America, continental Africa, Europe, Antarctica and Australia. The fi rst plane of the fi gure shows a phororhacoid bird (cf. Lavocatavis africana) preying upon a caviomorph rodent (cf. Gaudeamus lavocati) and, close to the shore of a slow freshwater river, a polypterid polypteriform (left), a cichlid perciform (center) and lepidosireniform dipnoan (right). Artwork drawn by Emilio Lopez-Rolandi. SPECIAL ESSAY