Productacean brachiopod assemblages are described from 10 taphocoenoses from various facies of the Upper Permian Kapp Starostin Formation in Spitsbergen. Time and space relationships among the investigated phena are based upon a previously established chronostratigraphic correlation of the strata. 15 productacean species are distinguished, based upon analysis of their morphology and ecology. Their paleontological descriptions take into account the ranges of their ecophenotypic variation. Shells adapted to three modes of life are recognized among the considered Productacea: (1) forms stabilizing within loose bottom sediments, (2) forms floating at the surface of soft substrates, and (3) forms living just below the surface of quaggy substrates. Distribution of the productacean assemblages in the Kapp Starostin Formation is analyzed within the framework of a reconstruction of the history of the Permian sea in this area. The main ecological controls upon this distribution include stratification of the water, substrate suitability for settlement, and coastal influences on the marine environment. Because of their spatially limited distribution and unrecognized evolution within the considered time interval, the investigated brachiopods cannot be employed for biochronostratigraphy.
Stable isotopes 18O and 13C record of the Kapp Starostin Formation (Late Permian) is presented. The interdependence of δ18O nad δ13C isotope time series is applied for calculating paleotemperatures in the depositional basin of the Kapp Starostin Formation. The obtained results indicate overall cooling from c. 25°—10°C, and confirm some paleogeographical and paleoclimatical inferrences.
A rich collection of exceptionally preserved Lower Triassic fossil fish remains obtained during the Polish Spitsbergen Expedition of 2005 includes many isolated teeth believed to belong to a saurichthyid actinopterygian. Stable isotope analysis ( d 13 C and d 18 O) of putative Saurichthys teeth from the Hornsund area (South Spitsbergen) acting as a paleoenvironmental proxy has permitted trophic−level reconstruction and comparison with other Lower Triassic fish teeth from the same location. The broader range of d 13 C values obtained for durophagous teeth of the hybodont selachian, Lissodus , probably reflects its migratory behaviour and perhaps a greater feeding diversity. X−ray microcomputed tomography (XMT), a non−destructive technique, is used for the first time in order to elucidate de − tails of tooth histology, the results of which suggest that the method has considerable potential as a future analytical tool.