Splash-like marine biodiversity additions after the Cambrian

Abstract

Some Phanerozoic biotic radiations in the marine realm led to marine biodiversity additions, i.e., increases in the global number of genera to unprecedented levels. Each of the two alternative biodiversity curves implies five post-Cambrian events of this kind, which coincided with parts of the biotic radiations. However, differences between these curves do not allow to find coherent marine biodiversity additions with the only exception of those occurred at the interval of the Great Ordovician Biodiversification. The attempted interpretations indicate that the marine biodiversity additions increased the number of marine genera by 10-30 % (from the previous unprecedented level to that new). All additions were relatively brief and occurred as splashes throughout the Phanerozoic. Peculiar intrinsic and extrinsic factors, as well as the speed of diversification should be considered when triggers of these events are looked for. Undoubtedly, splash-like marine biodiversity additions played an important role in the evolution of life in the sea, but a lot of research is required in order to understand their true nature.