Upper Cambrian Rehbachiella and the Phylogeny of Brachiopoda and Crustacea

Dieter Walossek is the author of Upper Cambrian Rehbachiella and the Phylogeny of Brachiopoda and Crustacea, published by Wiley.

• Introduction 3 Stratigraphy and taphonomy 3Palaeoecology and environmental conditions 3Size and developmental stages 5Systematic status of orsten arthropods 6Material and methods 6Material 6Methods 7Processing and measurements 7Two larval series 8Terminology 8Systematic palaeontology 10Rehbachiella kinnekullensis Müller, 1983 10Postembryonic development 13General remarks 13Development of series A 13Naupliar phase 13Post-naupliar phase 20Development of series B 30Naupliar phase 30Post-naupliar phaev31Unassigned specimens and further instars 39Life history 41Ontogenetic stages 41Two larval series 41Growth 42Morphogenesis 44Intraspecific variation 50Functional morphology and life habits 50Early Larvae 50Remarks 50Locomotion and feeding of the nauplii 51Advanced stages 54Functional ontogenetic changes 54Function of the advanced apparatus 56Mode of life and habitat 61Discussion 61Affinities of Rehbachiella 61Position within Crustacea s. str. (= crown-group Crustacea 61Exclusion of closer relationships with non-branchiopods 64General features and systematic status of Branchiopoda 67Relationships within Branchiopoda and possible taxonomic position of Rehbachiella 70Characters of the two branchiopod lineages 73Anostraca 73Phyllopoda 77Comparative ontogeny 80Remarks 80Development of Rehbachiella as a comparative reference series 82Comparisons 83Results 83Conclusions 90Comparisons of locomotory and feeding apparatuses 95General remarks 95The bipartite locomotory and feeding apparatus 99Comparisons 100The branchiopod model of the limb apparatus of Rehbachiella 105Significance of morphological details 107Neck organ 108Cephalic shields and carapaces 110Structures in the head region 114Appendages 115Ventrocaudal processes 120Segmental organs 120Tagmosis 120Concluding remarks 121Acknowledgements 124References 125Addendum 133Plates 134List of abbreviations 202List of Figures