The study of septal patterns in ammonoids has been centered on functional and/or constructional issues. Complexly fluted septa have been considered as complementary structures that reinforce the ammonite shell, their frilled sutures possibly manifesting the demand for strength. Ammonitic sutures display features that denote typical fractal behavior, since they can present very long perimeters r...

This paper discusses the phyletic interpretation of the genus Phricodoceras and its taxonomic classification at the subfamily, family, and superfamily levels from an historical and critical perspective. First a review of the latest findings on this taxon is presented and the grounds for the attribution of Phricodoceras to the Schlotheimiidae (Psiloceratoidea) are summarized and illustrated. Thi...

The Lower Pliensbachian series (Ibex Chronozone) of Southern Vendée (France) contains a unique mix ammonites, with several Polymorphitidae, Uptonia atlantica [Fauré and Bohain, 2017], Dayiceras dayiceroides [Mouterde, 1951], whose distribution till date seemed restricted to the Lusitanian Basin. As in Portugal, these taxa extend linear evolutionary sequence this family during Masseanum Valdani ...

Diatoms are one of the most important eukaryotic primary producers in lower ecosystem; understanding their evolutionary history is therefore also important. Throughout Cenozoic hydrosphere, diatoms have flourished. However, as a result progressive diagenesis and dissolution opaline silica that forms frustules, early evolution during Cretaceous unclear, so fossil record incomplete. Largely becau...

The stratigraphic framework of the uppermost Jurassic Lower Cretaceous interval of the Gulf area is revised using both historical and recently acquired paleontological (ammonites, calpionellids, foraminifers, 'calcareous' algae), sedimentological and sequential information. The Kahmah regional Series ranging in age from Late Tithonian to Gargasian (= middle Aptian) times is subdivided into regi...

The newly recognized Konservat-Lagerstätte of Ettling (Bavaria), field site of the Jura-Museum Eichstätt (JME), is unique among Late Jurassic plattenkalk basins (Solnhofen region) in its abundant, extremely well preserved fossil vertebrates, almost exclusively fishes. We report actinopterygians (ginglymodins, pycnodontiforms, halecomorphs, aspidorynchiforms, "pholidophoriforms," teleosts); turt...