Bruno Cahuzac

Crocodilian faunal renewal in the Upper Oligocene of Western Europe

The presence of Tomistomine Crocodilians (Tomistoma sp.) is first recorded in the Upper Oligocene of Western Europe (Chattian, Saint-Geours-de-Maremne, Aquitaine basin). Immigration, probably of Asiatic origin, occurred ca. 26 Ma, prior to the previously earliest records for Lowermost Miocene. Tomistoma points to warm, at least subtropical environments, in agreement with data on invertebrates and fish fauna. Immigrations to Western Europe of Tomistoma (and of Gavialis, in Miocene times) during Upper Oligocene and Lower-Middle Miocene seem related to climatic warming and eustatic rise events. There was a renewal of the European Crocodilian fauna, much impoverished in Late Eocene and reduced to Diplocynodon.

Heterostegina matteuccii sp. nov. (Foraminiferida: Nummulitidae) from the lower Oligocene of Sicily and Aquitaine: a possible transatlantic immigrant

The systematics and phylogenetic relations of the Oligocene species of Heterostegina (Nummulitidae) are poorly known compared to those of Eocene and Miocene species. The new species Heterostegina matteuccii sp. nov., characterized by the combination of an advanced nepionic stage (i.e. very few operculine chambers) and a relatively small proloculus, is here described from the lower Oligocene Caltavuturo Formation of Portella Colla (Madonie Mts, Sicily, Italy). The same species is recorded also in the ‘Calcaire à astéries’ Formation of Illats (Northern Aquitaine, near Bordeaux, France). Biometrically, H. matteuccii sp. nov. does not fit within any known Neo-Tethyan lineage of Heterostegina from the Eocene to the Miocene, and hence is considered to be a member of a distinct phyletic lineage. The advanced nepionic stage of H. matteuccii sp. nov., however, calls for the existence of predecessors. The Priabonian (and possibly also earliest Oligocene) H. ocalana Cushman, 1921 from the American-Caribbean realm is here interpreted as the most probable ancestral form for the H. matteuccii lineage. Thus, an early Oligocene eastward transatlantic migration of this lineage may be inferred. New results of strontium isotope stratigraphy from both sides of the Atlantic Ocean are consistent with this hypothesis. http://zoobank.org/urn:lsid:zoobank.org:pub:CC54DB64-091D-4CDE-A6AB-6DC620F0FC23