Setatella significans, a new name for mickwitziid stem group brachiopods from the lower Cambrian of Greenland and Labrador

Abstract

Setatella significans gen. et sp. nov. from the Lower Cambrian of North-East Greenland, originally described under the name ‘Mickwitzia cf. occidens’, is introduced as a probable stem group brachiopod. Newly collected specimens of Setatella significans from the Forteau Formation of southern Labrador exhibit new morphological details and provide a better understanding of its ontogeny. Setatella significans differs from species of Mickwitzia in having a ventral pseudointerarea and hemiperipheral growth in both valves. Setatella significans probably belongs to the derived stem group of the Linguliformea that can be differentiated from the more primitive Mickwitzia. The geographic range of Setatella is extended to southern Labrador.

Keywords:

• Brachiopoda
• Mickwitzia
• shell penetrating setae
• lower Cambrian
• Greenland
• Labrador

Acknowledgements

We are indebted to John S. Peel (Uppsala) for access to the collections of Lower Cambrian fossils from North-East Greenland and to Uwe Balthasar (Glasgow) and Douglas Boyce (St John's) for advice and practical assistance with field work in southern Labrador. Financial support from the Swedish Research Council (VR) to CBS, MS and LEH is gratefully acknowledged. Michal Mergl (Plzeň) and one anonymous reviewer are thanked for helpful suggestions that greatly improved the manuscript.