First record of a gladius-bearing coleoid Teudopsis bollensis Voltz (Cephalopoda, Coleoidea) in the Toarcian of the Western Carpathians (Slovakia)
ABSTRACT A fairly complete and relatively well-preserved gladius of the vampyropod coleoid cephalopod Teudopsis bollensis Voltz is recorded from the Lower Toarcian succession of the Kysuca Unit in the Pieniny Klippen Belt of Slovakia. These sediments are represented by dark-grey and black shales laid down in an oxygen-depleted environment during the Toarcian Oceanic Anoxic Event and potentially represent the first Jurassic ‘Konservat-Lagerstätte’ in the Western Carpathians. The first reliable record of the Early Jurassic genus Teudopsis from this area notably extends its palaeogeographic distribution to the northwestern continental margin of the Tethys Ocean. The systematics, palaeogeography and stratigraphy are briefly discussed in a European context.
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ABSTRACT: Until today, gladii of loligosepiid vampyropods have been difficult to distinguished owing to their fragmentary state of preservation. Re-study of a large set of loligosepiids from different Lower Jurassic localities has shown that the preservation of growth lines is sufficient to provide an unambiguous determination. Especially the course of growth lines within the hyperbolar zone is a highly characteristic feature. Members of the Loligosepiidae (Loligosepia, Jeletzkyteuthis) display a deeply concave (V-shaped) hyperbolar zone. Members of the Geopeltidae, on the other hand, show weakly concave (Parabelopeltis), or even straightened (Geopeltis) growth lines. Gladii of Loligosepia can be distinguished from Jeletzkyteuthis by the transition lateral field/hyperbolar zone. The genus Loligosepia is characterised by abrupt backwards bent growth lines forming an elongated spine-like projection, whereas the transition is more arcuated in Jeletzkyteuthis. According to the present results, Loligosepia aalensis, Loligosepia bucklandi, Jeletzkyteuthis coriaceus, Geopeltis simplex, and Parabelopeltis flexuosa are re-described. In the course of taxonomic treatment, a lectotype of Jeletzkyteuthis coriaceus is designated and the morphologic independence of Parabelopeltis flexuosa reaffirmed. As can be inferred from the course of growth lines, Parabelopeltis and Geopeltis, members of the Geopeltidae, seems to be phylogenetically closest to Recent Vampyroteuthis infernalis.Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 06/2008; 249(1):93-112. · 0.92 Impact Factor
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ABSTRACT: The Pliensbachian–Toarcian interval was marked by major environmental disturbances and by a second-order mass extinction. Here, we reappraise the taxonomic, spatiotemporal and selective dynamics of extinctions over the whole interval, by analysing a high-resolution dataset of 772 ammonite species from NW Tethyan and Arctic domains. On average, 40–65% of ammonite species disappeared during each subchronozone, but higher extinction pulses (reaching 70–90%) prevailed from the Margaritatus to the Dispansum Chronozone. The main extinctions, corresponding to the Gibbosus, Pliensbachian–Toarcian boundary, Semicelatum, Bifrons–Variabilis, and Dispansum events, differed in their dynamics, suggesting episodes of ecological stress related to climate change, regression, disturbance in the carbon cycle or anoxia. The multi-pulsed volcanic activity in the Karoo–Ferrar province could well have triggered these ecological changes. In addition, ammonites experienced a morphological bottleneck during the Gibbosus event, 1 Ma before the Early Toarcian diversity collapse. Typically, drops in richness were related both to high extinctions and to declines in origination rates. This feature could result from strengthened ecological stresses related to the temporal overlap of environmental disturbances. After the Early Toarcian crisis, the recovery of ammonites was rapid (2 Ma) and probably influenced by a coeval marine transgression.Journal of the Geological Society 01/2010; 167:21-33. · 2.58 Impact Factor
- Ferrantia. 01/2010;