Phylogeography of Ordovician–Silurian rhynchonelliformean brachiopods: tracking higher order distributional patterns, radiations and extinctions in 4D

Abstract

Based on a large data-set, spanning the Ordovician–Early Silurian (Telychian) interval, this study explores the phylogeographic distributional pattern for higher orders of rhynchonelliformean brachiopods through four time slices: Tremadocian, Dapingian–Darriwilian, Katian and Telychian. In addition, a palaeobathymetrical analysis has been conducted for the latter two time slices to assess the phylogenetic impact of the Late Ordovician mass extinctions at various palaeowater depths. Whereas the Tremadocian time slice exhibits phylogenetically simple regions characterized by orthide and porambonitoid taxa, these increase in complexity up through the Ordovician and become dominated by the strophomenides. By the Silurian this phylogentic composition shifted once more to atrypide- and pentameride-dominated faunas.

Keywords::

• phylogeography
• biodiversity
• species pumps
• Benthic Assemblage zones
• palaeobathymetry

Acknowledgements

Maria Liljeroth is thanked for compiling the data-set for the Tremadocian–Darriwilian interval. I further thank Trond Torsvik, Oslo, for providing the palaeogeographical projections, as well as, Rong Jia-yu, Nanjing, for providing me with his assessment of BA zones in the Chinese sections used for this study. Furthermore, Jisuo Jin and Peter Sheehan are thanked for very constructive reviews. Finally, I would like to thank the Danish Council for independent Research | Natural Sciences for financial support to this study. This paper is a contribution to IGCP project 591 – The Early to Middle Paleozoic Revolution.