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Abstract
The End Ordovician Extinction Event (EOEE) had little impact on supra-specific diversity and disparity within the order Conulariida (Scyphozoa, Cnidaria). With two possible exceptions (Exoconularia and Glyptoconularia), all eight genera currently known from strata of middle or late Katian age survived the crisis, and nearly all of the discontinuous gross morphological features present in Ordovician and older genera are present in at least one of the surviving genera. A cladistic parsimony analysis of 17 genera, 12 of which occur in Ordovician strata, produced 3 major subclades and 7 less inclusive subclades within Conulariida. With one possible exception, the clade Anaconularia+Baccaconularia, all other monophyletic groups within Conulariida survived the EOEE. Moreover, additional, ghost lineages in the clade Climacoconus+Holoconularia+Notoconularia+Paraconularia+Reticulaconularia must have crossed the Ordovician–Silurian boundary. The minor impact of the EOEE on diversity and disparity within Conulariida probably reflects the eurytopic character and simple but efficient metabolism (possibly glycolysis-based) of this group.
Acknowledgements
The senior author thanks the organizers of the Third Annual Meeting of the International Geoscience Programme Project 591 for inviting him to participate in this conference. Permission to examine deposited museum specimens was granted by S. Albright (NJSM), the late T. H. Bolton (GSC), J. Darrell (NHM), N. Eldredge (AMNH), R. Eng (MCZ), A. D. Kollar (CM), J. Liston (GLAHM) and J. Waddington (ROM). ACM is associated with the Research Center of Marine Biodiversity of the University of São Paulo and is supported by CAPES, CNPq and FAPESP. Finally, the authors thank Christian Rasmussen and Ian Percival for their constructive comments on an earlier version of this paper.