Taxonomical revision of the perisphinctid ammonites of the Upper Jurassic (Plicatilis to Planula zones) described by Józef Siemiradzki (1891) from the Kraków Upland

Abstract

This systematic account contains descriptions of ammonite species of the superfamily Perisphinctoidea from the collection of the Physiographic Commission of the 19th century Academy of Arts and Sciences in Kraków. The emphasis is on the description of 11 species introduced by Siemiradzki (1891), e.g. Subdiscosphinctes kreutzi, S. mindowe, S. jelskii, S. dunikowskii, S. ? cracoviensis, S. ? dybowskii, Perisphinctes (Perisphinctes) vajdelota, Perisphinctes (Dichotomosphinctes) crotalinus, P. (Dichotomoceras) alpinus, and Perisphinctes damesi recognised to be nomen dubium, as well as a single species from the Bimammatum Zone – Ringsteadia teisseyrei. Most of the species mentioned are re-described and illustrated for the first time in this paper. In addition, the descriptions of 18 nominal species as well as another 32 species left in open nomenclature, are provided. The species are assigned to 8 genera (Subdiscosphinctes, Perisphinctes, Neumannia, Passendorferia, Idoceras, Orthosphinctes and Ringsteadia) in 3 families (Perisphinctidae, Ataxioceratidae and Aulacostephanidae). In the family Perisphinctidae two new informal species groups have been distinguished: Perisphinctes (Dichotomosphinctes) elisabethae group and the Subdiscosphinctes ? dybowskii group. The Subdiscosphinctes ? cracoviensis group as distinguished by Brochwicz-Lewi�ski, has been re-described and some new forms included in it. The species indicate the Plicatilis and Transversarium zones of the Middle Oxfordian, and the Bifurcatus, Bimammatum and Planula zones hitherto as a whole assigned to the Submediterranean Upper Oxfordian, but in fact correlating with the Upper Oxfordian (Bifurcatus Zone and the lower part of the Bimammatum Zone) and the lowermost Kimmeridgian (upper part of the Bimammatum Zone and Planula Zone) of the Subboreal primary standard for the Oxfordian/Kimmeridgian boundary. The erroneous opinion presented by Siemiradzki (1891) concerning the alleged discordant occurrence of Kimmeridgian deposits of the so called Oppelia tenuilobata Zone in the area studied has been corrected and explained. The paper is provided with some useful species inexes