The Neoproterozoic assembly of Gondwana and its relationship to the Ediacaran–Cambrian radiation

Abstract

The assembly of the Gondwana supercontinent during the waning stages of the Proterozoic provides a tectonic backdrop for the myriad biological, climatological, tectonic and geochemical changes leading up to, and including, the Cambrian radiation. A polyphase assembly of Gondwana during the East Africa, Brasiliano, Kuungan and Damaran orogenies resulted in an extensive mountain chain which delivered nutrients into a shifting oceanic realm. An analysis of key evolutionary events during this time period reveals the following (a) several fauna show well established endemism that may be rooted in a cryptic evolutionary pulse (c). 580 Ma (b) the margins of the Mirovian and Mawson Oceans formed the locus of radiation for the Ediacaran fauna (c) the margins of the Iapetan and Mirovian oceans form the olenellid trilobite realm (d) the margins of the Mawson and Paleo-Asian oceans are the birthplace of the so-called Gondwana Province fauna (e) evolutionary events associated with the Cambrian radiation were likely driven by internal (biological) changes, but radiation was enhanced and ecosystems became more complex because of the geochemical, ecological and tectonic changes occurring during Ediacaran–Cambrian periods.