Annales Societatis Geologorum Poloniae (2015), vol. 85: 587–626. doi: http://dx.doi.org/10.14241/asgp.2015.037 HOW MANY UPPER TRIASSIC BONE-BEARING LEVELS ARE THERE IN UPPER SILESIA (SOUTHERN POLAND)? A CRITICAL OVERVIEW OF STRATIGRAPHY AND FACIES Joachim SZULC 1 , Grzegorz RACKI 2, 3 , Karol JEWU£A 1 & Jan ŒRODOÑ 2 1 Institute of Geological Sciences, Jagiellonian University, Oleandry 2a, 30-063 Kraków, Poland; e-mail: joachim.szulc@uj.edu.pl 2 Institute of Geological Sciences, Polish Academy of Sciences, Research Centre in Kraków, Senacka 1, Kraków, Poland; e-mail: ndsrodon@cyf-kr.edu.pl 3 Faculty of Earth Sciences, University of Silesia, Bêdziñska 60, 41-200 Sosnowiec, Poland; e-mail: grzegorz.racki@us.edu.pl Szulc, J., Racki, G., Jewu³a, K. & Œrodoñ, J., 2015. How many Upper Triassic bone-bearing levels are there in Upper Silesia (southern Poland)? A critical overview of stratigraphy and facies. Annales Societatis Geologorum Poloniae, 85: 587–626. Abstract: At least three widely separated bone-bearing intervals in the Upper Triassic succession of Upper Silesia, ranging in age from the Carnian to Rhaetian (i.e., in the interval of 25 Ma), are presented in papers by the Warsaw research group, led mainly by Jerzy Dzik and/or Grzegorz NiedŸwiedzki. The stratigraphic arguments are reviewed for the vertebrate localities studied so far, in particular for the well-known middle Keuper sites at Krasiejów and Lipie Œl¹skie, to show that the previously proposed age assignments are still inadequately documented and questionable. This unreliability is exemplified by the evolving stratigraphic correlation of the fragmentary Silesian sections (8–18 m thick) with informal subsurface units from central-western Poland and with the German standard succession, ultimately not corroborated by comparison with the composite reference succession of the Upper Silesian Keuper, including new profiles (ca. 260 m thick) from the WoŸniki K1 and Patoka 1 wells. Based on a multidisciplinary stratigraphic study covering consistent litho-, bio-, climato- and chemostratigraphic premises, focused on the regional reference section, two bone-bed levels only are recognized in the Patoka Marly Mudstone-Sandstone Member (= Steinmergelkeuper) of the Grabowa Formation, not very different in age (Classopollis meyeriana Palynozone; probably IVb Subzone): (1) the localized Krasiejów bone breccia level (early Norian in age) in the Opole region, and (2) the far more widely distributed Lisowice bone-bearing level (middle Norian) in a vast alluvial plain (braided to anastomosing river system) during the Eo-Cimmerian tectonic-pluvial episode. As a consequence of the principal uncertainties and controversies in Upper Triassic terrestrial stratigraphy, this is still a somewhat preliminary inference. Typical skeletal concentra- tions of a combined hydraulic/sedimentologic type, related to fluvial processes, are common in the Upper Silesian Fossil-Lagerstätten, although factors governing preservation are probably important, as well. Key words: Bone beds, lithostratigraphy, palynostratigraphy, chemostratigraphy, taphonomy, Grabowa Forma- tion, middle Keuper, Upper Silesia. Manuscript received 25 August 2015, accepted 9 December 2015 INTRODUCTION The Triassic, as the period between the two great extinc- tions, was characterized by the substantial reconstruction of continental tetrapod communities (Benton, 2004). After the discovery of very rich bone accumulations in southern Po- land at Krasiejów village, near the town of Ozimek, and at Lisowice village (Lipie Œl¹skie clay pit), near the town of Lubliniec (Dzik et al., 2000, 2008a, 2008b), a new and at- tractive scientific perspective surprisingly emerged for pre- viously abandoned studies of the Polish Keuper (Racki, 2010; compare Szulc, 2007c). The tetrapod localities have major cognitive importance for the evolution of many im- portant groups of amphibians and reptiles (Dzik et al., 2000, 2008a; Dzik and Sulej, 2007; Sulej and NiedŸwiedzki, 2010; NiedŸwiedzki, 2012; NiedŸwiedzki et al., 2014), and even mammals (Œwi³o et al., 2014). Accordingly, it seems hard to overestimate the importance of the Silesian ‘grave- yards’ with reference to the study of Late Triassic evolu- tionary patterns, exemplified by the still obscure dawn of di-