Based on material from the uppermost Tithonian La Caja Formation at Puerto Piñones, northeastern Mexico, the complete ontogenetic development (protoconch to adult) of the ammonite Salinites grossicostatum is outlined by a detailed morphometrical shell analysis. The embryonic stage, consisting of a small ellipsoid protoconch and ammonitella, ends at about 0.6 mm. Four major morphological changes...

The present study is a contribution to the lithostratigraphy of Middle Jurassic strata in area Zimevitsa Plateau (West Balkan Mts, West Bulgaria). Based on its lithological and regional properties, Dobravitsa Member distinguished from surrounding rocks Etropole Formation. new member consists alternating shales, siltstones fine-grained sandstones. It also contains abundant siderite calcite concr...

The uppermost Albian and lowermost Cenomanian succession at Abouda Plage, north of Agadir, in the Agadir Basin, western Morocco, is described detail, ammonites, microcrinoids planktonic foraminifera are recorded illustrated. lower part Ait Lamine Formation yields ammonites indicative the  Pervinquieria (Subschloenbachia) rostrata P. ( S. ) perinflata ammonite zones, Thalmanninella appenninica f...