Upper Toarcian – Middle Aalenian (Jurassic) Erycitinae SPATH (Ammonitina) from the Gerecse Mts, Hungary

The Upper Toarcian–Middle Aalenian sequences of the Gerecse Mts belong to the Mediterranean region of the Mediterran–Caucasian Realm, bigger part of the Ammonoidea collected here are represented by the suborders Phylloceratina and Lytoceratina. In this paper the species belonging to the subfamily Erycitinae SPATH are documented as a contribution to the general taxonomic and biostratigraphic revision of the Ammonitina fauna. Considering the abundance and diversity of the subfamily, it was a dominant group in the Meneghinii to Opalinum Zones: during its acme Erycitinae formed 52% of the Ammonitina. Two genera, one subgenus and 15 species are represented by 117 determined specimens. Quantitative evaluation and problems of systematics are briefly discussed, genera and species are described. Introduction of two new taxa, Cagliceras enigmaticum n. sp. and Erycites gerecsensis n. sp. is designated

Csernye revisited: New ammonite finds and ostracods from the Lower Jurassic Pliensbachian/Toarcian boundary beds in Bakonycsernye, Transdanubian Hungary

Recently a new exposure near the classic outcrops at Bakonycsernye made possible to make a closer study on the Pliensbachian/Toarcian boundary beds. Careful sampling and the reinvestigation of formerly collected but unpublished material (ammonites and microfossils) evidenced that in the new section the hiatus between the Pliensbachian massive red limestone and the Toarcian claymarl is much shorter than suggested before, on the basis of previous exposures. The earliest Toarcian ammonite in the new section is Paltarpites cf. paltus of the Paltus Subzone, while the earliest Toarcian ammonites in the classic Csernye section indicated the Falciferum Zone. The ammonite fauna shows no abrupt change at the chronostratigraphic boundary: most of the represented morphological lineages are continuous across, while the ostracod fauna, having been represented by benthonic forms, reacted heavily to the limestone to claymarl facies change at the boundary: the former sublittoral elements are replaced by deper-water forms in the Toarcian. To document these circumstances and changes, the most important ammonites and ostracods from the new section and from the boundary beds of the classic Csernye section are figured and stratigraphically evaluated

Remarks on the Toarcian–Aalenian fossil assemblage of the Kis-Teke Hill, Gerecse Mts (Hungary)

The red, nodular marl beds of Toarcian-Aalenian age of the Kis-Teke Hill yielded a rich fossil assemblage consisting of gastropods, bivalves, ammonites, belemnites and brachiopods. The ammonite fauna proved to be especially abundant and diverse and the relatively high percentage of Ammonitina allowed a biostratigraphical subdivision of the section. Beside representatives of taxa characteristic of the peri-Mediterranean Jurassic some rare genera including Urkutites, Rarenodia, Praerycites and Staufenia have also been encountered. These and some other interesting forms are described

Ammonite stratigraphy of a Toarcian (Lower Jurassic) section on Nagy-Pisznice Hill (Gerecse Mts, Hungary)

Abstract In the Jurassic rocks exposed in a small abandoned quarry on the northwestern edge of Nagy-Pisznice Hill in the Gerecse Mts, fairly well preserved parts of a crocodile skeleton was found in 1996. The bed which yielded the skeletal remains is the uppermost layer of the Kisgerecse Marl Formation exposed here and was determined as belonging to the Upper Toarcian Grammoceras thouarsense Zone. The beds of the sequence above and below were carefully sampled in the late 1990s, and the encountered ammonites were evaluated biostratigraphically. As a result, the Lower Toarcian Harpoceras serpentinum Zone, the Middle Toarcian Hildoceras bifrons and Merlaites gradatus Zones, and the Upper Toarcian Grammoceras thouarsense and Geczyceras speciosum Zones were identified. Within most of these zones the subzones and even the faunal horizons were successfully recognized. The lowermost beds above the underlying Pliensbachian red limestone did not yield any fossils; thus the lowermost Toarcian Dactylioceras tenuicostatum Zone could not be documented. The highest Toarcian ammonite zones also remained unidentified, because the beds of the Tölgyhát Limestone above were not sampled all the way up. This paper presents the lithostratigraphic and biostratigraphic details of the sequence, and the paleontological descriptions of the most important ammonites