|mhorn||Дата: Saturday, 09.02.2013, 22:24 | Сообщение # 1|
|Meister C., Lafaurie G., Marshal A. (2012) Les ammonites du Sinémurien supérieur et du Pliensbachien basal dans les Causses (Lot, Aveyron, Lozère), France // Revue de Paléobiologie, Vol.31. no.2. P. 347-423 |
New ammonite collects, more than 80 specimens, allow a detailed analysis of the Sinemurian - Pliensbachian boundary in the Causses basin. The originality of this fauna bases on the presence of rare or little known taxa such as Epideroceras gr. steinmanni, Paltechioceras aureolum, P.cf. meisteri, P.cf. elicitum for the Sinemurian and as Apoderoceras dunrobinense, Tetraspidoceras gr. quadrarmatum (Dumortier) and Carixiceras aff.involutum for the Pliensbachian. The biostratigraphic framework is completed by six new biohorizons which become integrated perfectly into the sequence of the biohorizons which cover the Late Sinemurian, Pliensbachian and Toarcian of the Causses basin. These biostratigraphic units are also correlated to the Standard Zonation of the NW Europe. During the Late Sinemurian and the Early Pliensbachian, the provincialism is strong and with the exception of some Paltechioceras such as P.gr. tardecrescens and P. oosteri which are species with very wide geographical distribution, most part of the other species show strong paleogeographic affinities with the Euroboreal Domain and the North Tethyan Margin.
Middle Jurassic - Lower Cretaceous ammonites & aptychi