Hildoceras bifrons (Bruguière, 1789) is a cosmopolite ammonite species from the Lower Jurassic of Boreal and Mediterranean (Tethys) palaeogeographical provinces. Inter-demic phylogenetic variability are noticeable, also affecting most distinctive morphological trait: spiral groove along whorl flank. Since XIX century, however, number morphotypes assigned to (many which Apennines other Italian l...

An assemblage of large and robust pedunculate scalpellomorph cirripede barnacles from the Maastrichtian Kalaat Senan (Tunisia) is described, their stratigraphical position within Abiod El Haria formations noted. Four taxa are documented, three which confined to area, namely Pachyscalpellum heltzeli , Cretiscalpellum robaszynskii sp. nov. Diotascalpellum sp.; fourth, curvatum was previously reco...

In 2013, Andra (French National Radioactive Waste Management Agency) drilled boreholes to the south-east of Paris Basin, characterise Aptian and Albian clayey formations, including ‘Argiles à Plicatules’ Formation dated as early Aptian. One these intersected this formation with an excellent recovery allowing detailed biostratigraphy (ammonites), sedimentology, clay mineralogy, isotope geochemis...

Abstract The early Cenomanian crippsi Event comprises a 1–3-m-thick interval characterised by mass occurrences of the inoceramid Gnesioceramus , identified in uppermost Sharpeiceras schlueteri Subzone (lower lower Mantelliceras mantelli Zone), below an interregional sequence boundary (SB Ce 1). At Lüneburg, event is densely packed, very large, disc-like valves G . Taphonomy as well bio- and mic...