The foraminiferal limestones from the Middle Eocene Central Istrian region illustrate progressive deepening of depositional gradients. Shifting of Lower Cuisian to Upper Lutetian microfacies can be described in terms of a ramp model. The Orthophragminae-bearing parts of the foraminiferal limestones are interpreted in terms of larger foraminiferal faunal associations, planktonic foraminiferal relative abundance, limitations of algal endosymbionts, foraminiferal lamellar thickness and flattening of test shapes. Microfacies I contains the most diverse larger foraminiferal association with a predominance of large, thick nummulitids, assilinids, and asterocyclinids. Microfacies II is characterized by a gradual increase of Orthophragminae diversity and abundance. Nummulitids, equally abundant, are dominated by lenticular and subspherical specimens. The reduction in number of nummulitid specimens with characteristic biconical radiate morphologies, and relative abundance of flattened orthophragminids, characterizes Microfacies III. Scattered biodestructed orthophragminid tests and planktonic foraminifera constitute Microfacies IV, indicating the end of a long-lasting, shallow-marine Adriatic Carbonate Platform regime.

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The Shallow Benthic Zonation is one of the most important achievements of biostratigraphy in the last twenty years. Here we summarize the state of the art in the field of Larger Benthic Foraminifera (LBF) and sketch the main lines of research that are improving the precision and usefulness of this scale. The goal of updating the zonation requires a wealth of data coming not only from biostratigraphic investigations but also from paleoenvironmental analyses, biological knowledge, rigorous taxonomic determination, and understanding of paleobiogeography. The papers collected for this special issue are contributions to this broad research program

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Paleobiogeographic distribution within the larger, trematophore miliolids was evaluated using presence/absence (Parsimony Analysis) patterns and distributional extension of 7 genera and 47 species from the Coniacian to the Oligocene. The oldest group of larger miliolids (from late Cretaceous), represented by four parallel genera (Periloculina, Lacazina, Pseudolacazina, Idalina) from the southern Pyrenean province exhibits an endemic character. Later periods of the Senonian with uniform distribution of miliolids over the shallow-marine carbonate environments in the western and central Neotethys are characterized by reduction in generic diversity and in abundance of individuals. The morphological analysis indicated four major biogeographic regions for the Eocene larger Miliolids: 1) the Caribbean, 2) the "European" Neotethys (western, central and eastern), 3) the North African Neotethys (southern) and 4) the Indo-Pacific. The morphological biogeographic pattern corresponds to the circum-global Eocene current ocean system and the prevailing temperature sea surface gradient along tropical-subtropical paleolatitudes. A tendency to endemism can be observed for Fabulariids in the Caribbean during the Middle and Upper Eocene, and for Lacazinella during the Middle and late Eocene to Oligocene in the New Guinea and Molucca regions.Résumé. -La distribution paléogéographique des grands, trématophore miliolidés a été évaluée en utilisant les schémas présence/absence (analyse parcimonieuse) et la répartition géographique de 7 genres et 47 espèces du Coniacien à l'Oligocène. Le groupe le plus ancien des grands miliolidés du Crétacé supérieur, représenté par 4 phylums parallèles (Periloculina, Lacazina, Pseudolacazina, Idalina) dans la province sud pyrénéenne montre un caractère endémique. Les périodes suivantes du Sénonien à distribution uniforme des miliolidés dans les environnements carbonatés marins peu profonds sont caractérisées par une réduction de la diversité générique et l'abondance des individus. L'analyse morphologique indique 4 provinces biogéographiques principales pour les grands miliolidés de l'Eocène: 1) Les Caraïbes, 2) la Neotéthys "européenne", 3) la Neotéthys nord-africaine et 4) l'Indo-Pacifique. Le schéma biogéographique morphologique correspond au système de courant océanique circum-global éocène et au gradient dominant des températures de surface des mers aux paléolatitudes tropicales-subtropicales. La tendance à l'endémisme peut être observée chez les Fabulariias des Caraïbes à l'Eocène moyen et supérieur, chez les Lacazinella à l'Eocène moyen et terminal jusqu'à l'Oligocène, en Nouvelle-Guinée et dans la province des Moluques.

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