The trace fossil chondrites in uppermost Jurassic-lower cretaceous deep cavity fills from the Western Carpathians (Czech Republic)

The common marine trace fossil Chondrites occurs in thin layers in laminated micrites which fill deep submarine cavities in peri-reefal biocalcarenites and calcirudites of the Tithonian-Berriasian Stramberg Limestone. The cavity fills display several generations which originated during long periods of time. Periodic colonization of this very stressful environment by the Chondrites trace maker was possible probably owing to episodic deposition of more oxygenated and more nutritious sediment at a certain stage of development of the cavities related to increased tectonic activity during the Berriasian. In more bioturbated laminae ?Palaeophycus also occurs. The occurrence of Chondrites in fillings of deep cavities represents new evidence for adaptation of its trace maker to stressful environments

Carbon cycle history through the Jurassic–Cretaceous boundary: A new global δ13C stack

publisher: Elsevier articletitle: Carbon cycle history through the Jurassic–Cretaceous boundary: A new global δ13C stack journaltitle: Palaeogeography, Palaeoclimatology, Palaeoecology articlelink: http://dx.doi.org/10.1016/j.palaeo.2016.03.016 content_type: article copyright: Copyright © 2016 Published by Elsevier B.V

Early Cretaceous ribbed aptychi – a proposal for a new systematic classification

The older system for classification of ribbed calcareous Early Cretaceous aptychi consisted of two genera: Punctaptychus and Lamellaptychus. Later, I. Turculet divided Lamellaptychus into several subgenera. Within the framework of both the genera, species and subspecies were distinguished, which resulted in binominal and trinominal nomenclature. With regard to the richness of newly described species and subspecies in recent years, is not possible to continue using the original system. It is the basic ribbing that plays the decisive role in the generic and subgeneric classification of ribbed aptychi. In the case of subspecies systematics, all details on the valve surface are used with the exception of the sigmoidal bend (fractocostatus) and radial lines (radiatus). The ribbed aptychi are newly divided into the following families: Punctaptychidae fam. nov. and Lamellaptychidae fam. nov. Within the family Punctaptychidae we are able to distinguish two genera: Punctaptychus Trauth, 1927 and Cinctpunctaptychus gen. nov. The family Lamellaptychidae includes five genera differing in the basic arrangement of the ribs: Lamellaptychus Trauth, 1927, Beyrichilamellaptychus Turculet, 1994, Mortilletilamellaptychus gen. nov., Thorolamellaptychus Turculet, 1994 and Didayilamellaptychus Turculet, 1994. Eight species and one subspecies are established as new: Cinctpunctaptychus undulatus, Beyrichilamellaptychus pseudostuderi, Mortilletilamellaptychus mortilletioides, M. submortilleti noricus, M. stanislavi, Didayilamellaptychus hennigi, D. andrusovi and D. renzi