Lower Palaeozoic brachiopod faunas from Baltoscandia, the south Urals and the United Kingdom

Introduction

Work on these projects is part of general research on a broad synthesis of present knowledge of Cambrian, Ordovician and Silurian lingulate and rhynchnelliformean brachiopod faunas, palaeobiogeography and brachiopod-based biostratigraphy across Baltoscandia, the South Urals and the United Kingdom. The main topics of this study are Early Ordovician (Billingenian) faunas of the East Baltic as the earliest examples of the Palaeozoic Evolutionary Fauna in Baltoscandia; taxonomical revision of various Cambrian to Silurian linguliformean faunas of Scandinavia, East Baltica and the United Kingdom. The early Ordovician rhynchonelliformian faunas of South Urals require revision because they represent an important link between the faunas of Gondwana and the Baltoscandian Basin. A considerable amount of work is also being done on the revision of some poorly known species and genera established in the nineteenth century.

(Click to enlarge)

Stratigraphical contact between the Upper Cambrian to Tremadocian Tosna Formation and the Middle Cambrian Sablinka Formation exposed on the east side of the Tosna river downstream of Gertovo waterfall (about 50km south-east of St Petersburg, Russia). deep cracks in unconsolidated sands of the Sablinka Formation represent probably ice vein casts suggesting freezing climate in the area at least sometime in the Late Cambrian. Note numerous Scolithos trace fossil in the overlying Tosna Formation.

This is the ongoing project dedicated to the taxonomical study of a number of the Cambrian - Silurian brachiopod faunas Baltoscandia, the south Urals and The United Kingdom. These studies confined not only to traditional palaeontological applications on the brachiopod taxonomy and biostratigraphy, but also focused on functional morphology (Bassettet al.2008), shell structure and composition (Streng et al . 2008), as well as various aspects of sedimentology. Study of rare earth elements in biogenic phosphates (mostly organophosphatic brachiopods and conodonts) proved useful for better understanding of palaeogeography and palaeoenvironments of the Baltoscandian basin in the Early Palaeozoic (Sturessonet al.2005).

References

Bassett, M.G., Popov, L.E. and Egerquist, E. 2008. Pedicle preservation in a Silurian rhynchonelliformean brachiopod from Herefordshire, England: soft-tissue or an artefact of interpretation? Earth and Environmental Science Transactions of the Royal Society of Edinburgh , 98 (for 2007), 303-308.

Streng, M., Holmer, L.E., Popov, L.E. and Budd, G.E. 2008. Columnar shell structures in early linguloid brachiopods – new data from the Middle Cambrian of Sweden. Earth and Environmental Science Transactions of the Royal Society of Edinburgh , 98 (for 2007), 221-232.

Sturesson, U., Popov, L. E., Holmer, L. E., Bassett, M.G., Felitsyn, S. and Belyatskyi, B. 2005. Neodymium isotopic composition of Cambrian-Ordovician biogenic apatite in the Baltoscandian Basin: implications for palaeogeographical evolution and patterns of biodiversity. Geological Magazine , 142, 419-439.