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Tescheniceras gen. nov. (Ammonoidea) and the definition of the Valanginian/Hauterivian boundary in Butkov Quarry (Central Western Carpathians, Slovakia)

Vašíček Zdeněk

Acta Geologica Polonica

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2020

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Vol. 70, no. 4

569--584

EN

Jurassic and Lower Cretaceous successions of the Manín Unit of the Central Western Carpathians are exposed in Butkov Quarry in the Middle Váh Region, Slovakia. A significant part of the macrofauna belonging to neocomitid ammonites, formerly classified under the genus Teschenites Thieuloy, 1971, occurs in deposits spanning the Valanginian/Hauterivian boundary. The original definition of Teschenites was accompanied by uncertainties in the taxonomic and stratigraphic position of its original type species, i.e., Hoplites neocomiensiformis Uhlig, 1902. The present contribution focuses on and provides a possible taxonomic solution by establishing the new genus Tescheniceras. In Butkov Quarry, the new genus includes five species. Tescheniceras flucticulum (Thieuloy, 1977), the type species, is the most abundant. Tescheniceras callidiscum (Thieuloy, 1971), the subzonal species for the uppermost Valanginian (Thieuloy 1971b), occurs only sporadically. Because Acanthodiscus radiatus (Bruguiére, 1789), the index species for the basal Hauterivian (radiatus Zone) in the international ammonite zonation, does not occur in the locality, the basal Hauterivian is indicated by the first appearance of the genus Spitidiscus Kilian, 1910.

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Towards a standard Tithonian to Valanginian calpionellid zonation of the Tethyan Realm

Lakova I., Petrova S.

Acta Geologica Polonica

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2013

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Vol. 63, no. 2

201--221

EN

A calpionellid zonal scheme is proposed for the Tithonian through Valanginian pelagic carbonates of the Western Balkan Unit, based on the vertical ranges of 57 chitinoidellid and calpionellid species recognized. This zonal scheme consists of calpionellid zones that are widely accepted in the Mediterranean Realm, such as the zones of Chitinoidella, Praetintinnopsella, Crassicollaria, Calpionella, Calpionellopsis, Calpionellites and Tintinnopsella. Subzonal divisions are comparable to those in the Carpathians. Direct correlations between ammonite and calpionellid ranges suggest that the base of the Upper Tithonian corresponds to the FO of Chitinoidella boneti; that of the Upper Berriasian to the FO of the genus Calpionellopsis; and the base and top of the Lower Valanginian to the FO and LO of the genus Calpionellites respectively. Correlations of the calpionellid zonation in the study area with zonations in other areas are discussed.

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Early Cretaceous ammonites from the Butkov Quarry (Manin Unit, Central Western Carpathians, Slovakia)

Vasicek Z.

Acta Geologica Polonica

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2010

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Vol. 60, no. 3

393-415

EN

The taxonomic and stratigraphic study of rich ammonite material from the Lower Cretaceous deposits of the Butkov Quarry, near Ladce (ManIn Unit, Slovak Central Carpathians) is presented. More than 55 ammonite species are recognised and twenty-one biostratigraphically significant ammonite species are described, with one species, Sarasinella subdensicostata, described as new. The recognised taxa document an interval from the Upper Valanginian through to the Lower Hauterivian. The ammonite assemblage represents the Mediterranean bioprovince, with only a single species, Dichotomites evolutus, from the Boreal bioprovince.a new ammonite zone, the Teschenites flucticulus Zone, is proposed for the basal Hauterivian in the Western Carpathians.