Palaeontological heritage in the XIXth century and the Physiographic Commission of the Polish Academy of Arts and Sciences in Kraków: museum exhibits or scientific value?

The stratigraphical study of the Upper Jurassic of the Krakow region was already underway in the XIXth century. The results of the first detailed mapping of the area were published by Zaręczny (1894) who collected many of the ammonites which were part of the ammonite collection of the XIXth century Physiographic Commission of the Academy of Arts and Sciences in Krakow. This collection was described by Siemiradzki in 1891. It is now in the Museum of Institute of Geological Sciences of the Polish Academy of Sciences in Krakow. It comprises around 360 specimens representing various ammonite groups: perisphinctids (Perisphinctidae, Ataxioceratidae and Aulacostephanidae - around 70%), Oppeliidae (about 26%), Cardioceratidae (3.4%) and rare phylloceratids (0.5%). Some of specimens were misinterpreted by Siemiradzki (1891, 1899) as Kimmeridgian taxa, resulting in a long lasting controversy about the occurrence of Kimmeridgian deposits in the Krakow region. The major part of the collection, however, represent Oxfordian perisphinctids, including the type specimens of several species described by Siemiradzki (1891 - e.g. Subdiscosphinctes kreutzi, S. mindowe, S. jelskii, "Perisphinctes" cracoviensis, Perisphinctes (Dichotomosphinctes) crotalinus and some others). They constitute a homogenous assemblage of the Middle and Upper Oxfordian, Transversarium and Bifurcatus zones and come mainly from Rudno and/or Brodła n. Krakow. Some of the specimens in the collection, however, are not precisely localized and the origin of some others, in particular those presented by private collectors, may be disputable (cf. Zaręczny 1894): such specimens must be treated with caution for detailed stratigraphical studies. Nevertheless, the collection provides valuable material for the palaeontological studies, and it is essential for the stratigraphical interpretation of exposures which are no longer available, for instance due to abandonment or infill (for instance the former quarries of Krakow Town and Rudno).