Abstract

Pannotia is a hypothetical supercontinent that may have existed briefly during the Proterozoic–Cambrian transition. Various lines of evidence used to argue for its existence include global orogenesis in Ediacaran–Cambrian time, the development of Cambrian passive margins and some (but not all) tectonic reconstructions. Indirect measures used to infer Pannotia's veracity include patterns of biological diversity, palaeoclimate, sea level, magmatism and other palaeoenvironmental proxies. It is shown herein that neither the direct records nor the indirect proxies provide compelling support for Pannotia. If that ephemeral contiguous landmass existed at all, its effects on the broader Earth system are inextricably tied to the more fundamental processes of Gondwanaland assembly. This perspective emphasizes the remarkable consolidation of Gondwanaland as a semi-supercontinent within the early stages of the Pangaea cycle. Gondwanaland's size combined with its c. 300 myr longevity might have greater significance for mantle dynamics than the larger, but shorter-lived, Pangaea landmass.