Abstract In this paper we present nine reconstructions for the Mesozoic and Cenozoic, based on previously published sea-floor spreading isochrons ∗ ∗ Larson et al. (1985). . The purpose of this study was 1. (1) to determine if the isochrons could be refitted to produce accurate plate tectonic reconstructions 2. (2) to identify areas of apparent mismatch between magnetic isochrons as a focus for further investigations, and 3. (3) to test the capabilities and accuracy of interactive computer graphic methods of plate tectonic reconstruction. In general, Tertiary and Late Cretaceous isochrons could be refitted with little overlap and few gaps; however, closure errors were apparent in the vicinity of the Bouvet and Macquarie triple junctions. It was not possible to produce Early Cretaceous reconstructions that were consistent with the previously published isochrons. In this paper we also propose that the Late Cretaceous and Early Tertiary plate reorganizations observed in the Indian Ocean were the result of the progressive subduction of an intra-Tethyan rift system.