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A new non-marine ostracod fauna from the Paleogene “hamadian deposits” outcropping west of Bechar (southwestern Algeria) has been recovered from lacustrine to fluvial deposits of the Oued Meridja section and fluvial deposits on the southern edge of the Hamada de Meridja section. Recently, these sections have been dated as late Thanetian – early Ypresian (latest Paleocene to earliest Eocene) and Ypresian – earliest Lutetian (early to earliest middle Eocene), respectively, based on charophytes. The associated ostracod fauna recovered consists of relatively mostly moderately to badly preserved specimens and comprises 14 taxa, none of which could be identified to species level in view of its poor state of preservation; we have nevertheless been able to identify and describe the following taxa: Herpetocypris sp., Cyprinotus? sp., Heterocypris? sp. 1 and sp. 2, Cypris? sp., Ilyocypris sp., Cytheroidea indet. sp. 1 and sp. 2, Limnocytheridae indet. sp. 1, Cypridoidea indet. sp. 1, Cyprididae indet. sp. 1, and Ostracoda indet. sp. 1, 2 and 3. Only Heterocypris sp. 1 occurs in both sections. Although the fauna can as yet not be related to the few other contemporaneous faunas reported from the wider palaeogeographic area, it adds important new information to our poor knowledge on Eocene non-marine ostracods in North Africa and southern Europe. The Meridja sections and area are promising regarding the discovery of more, better preserved material and further studies, and one main limitation to the correlation of the fauna is the hitherto insufficient taxonomic knowledge on many faunal elements of Eocene non-marine ostracods to which our section contributes considerably.

We here report the oldest remains (teeth) of the African tigerfish (Hydrocynus) from the Oued Méridja and Garet Dermchane sections, Hamada of Méridja deposits, in southwestern Algeria. The tigerfish, a large carnivorous fish today represented by several species in the freshwaters of Africa, was previously found in upper middle to upper Eocene deposits in Egypt and Libya. The remains described here are several million years older, being early to middle Eocene in age, and are associated with other fish elements including lungfish, polypterid, amiiform, possible cichlid, and Alestes and Brycinus material, along with several fish elements that cannot be associated with a specific taxon and some fragmentary amphibian bones. This represents the first detailed description of a freshwater fish assemblage from the Eocene of Algeria, although a short list of fish taxa from Eocene Algerian deposits was previously reported. Furthermore, these new Algerian fossils allow us to assess the hypothesized existence of an east–west or west–east hydrological connection between eastern and western parts of northern Africa. We suggest that the shared presence of tigerfish in the Eocene deposits of Algeria, Libya, and Egypt does not necessarily indicate a permanent (i.e., nonseasonal) connection east–west or west–east among these areas. Rather, the observed faunal similarities could have been the result of seasonal flooding that caused the dispersal of Hydrocynus and associated taxa across coastal flood plains.

The continental deposits of Oued Meridja area (west of Bechar, southwestern Algeria) have been assigned by previous authors to the early Eocene on the basis of lacustrine gastropod fauna (Pseudoceratodes). This study reports new paleontological and biostratigraphic data from the Oued Meridja section. Recent field investigations resulted in the discovery of an important charophyte assemblage, composed of five species belonging to four genera: Maedleriella cristellata, Maedleriella aff. cristellata, Harrisichara aff. leptocera, Peckichara disermas and? Gyrogona sp. This association allows to suggest a late Thanetian to early Ypresian age for this locality.

International audience; Terrestrial gastropods occur in many North African localities in Eocene continental deposits. Here we analyse the faunal assemblage from the Hamada de Méridja Formation in southwestern Algeria, dated as Early to Middle Eocene on the basis of charophytes. The assemblage consists of three closely related species that to date have been classified either in the extant Madagascan genus Leucotaenius v. Martens, 1860, or in the SW European Eocene genera Romanella Jodot, 1957 and Vicentinia Jodot, 1957. This is rejected for shell morphological and phylogeographical reasons, and a new classification as Maghrebiola gen. nov. is proposed. Maghrebiola is tentatively placed in the South American family Strophocheilidae, as species from the Early Eocene Itaboraí Basin of Brazil, currently placed in the genus Eoborus Klappenbach and Olazarri, 1970 in the family Strophocheilidae, superfamily Acavoidea, have a very similar shell habitus. This record possibly extends the known geographical range of the Strophocheilidae into the African continent during the Eocene. Immigration of this stock into North Africa during the Cretaceous via a still existing plate connection is assumed. An attribution of Maghrebiola to the African family Achatinidae is unlikely for shell morphological reasons despite certain habitus similarities, although the Priabonian genera Arabicolaria and Pacaudiella from Oman most likely belong into this family, and not to the Vidaliellidae as originally proposed. Possible causes for the very low diversity of the assemblage are mainly unfavourable living conditions, i.e. a relatively dry climate resulting in sparse vegetation and only occasional presence of water bodies, which may have had increased salinities, accounting for the lack of freshwater mollusks. The absence of any competing large gastropods may possibly have facilitated high intraspecific variability leading to sympatric occurrence of three closely related species, due to the animals occupying a wide range of available ecological niches. As the species discussed here have also been attributed to the genera Romanella and Vicentinia in the Vidaliellidae, we provide an appendix with annotated characterisations of most genera of the Vidaliellidae and list the nominal species assigned to them. This family is tentatively placed in the South American superfamily Orthalicoidea; its stock would have similarly immigrated from South America, but have successfully colonized mainly SW Europe, with only one Eocene species [Romanella kantarensis (Jodot, 1936)] recognized in Algeria.

2 PREMISE OF THE STUDY: The Paleogene deposits of the Hamada of Meridja, southwestern Algeria, are currently dated as lower-to-middle Eocene in age based on fossil gastropods and charophytes. Here we report the presence of fruits that can be assigned to the Boraginaceae s.str., apparently representing the fifossil record for this family in Africa, shedding new light on the historical biogeography of this group. METHODS: Microscopic studies of the fossil nutlets were carried out and compared to extant Boraginaceae nutlets, and to types reported in the literature for this family. KEY RESULTS: The fossils are strikingly similar in general size and morphology, particularly in the fi ner details of the attachment scar and ornamentation, to nutlets of extant representatives of the Boraginaceae tribe Echiochileae, and especially the genus Ogastemma . We believe that these nutlets represent an extinct member of this lineage. CONCLUSIONS: The Ogastemma -like fossils indicate that the Echiochileae, which are most diverse in northern Africa and southwestern Asia, have a long history in this region, dating back to the Eocene. This tribe corresponds to the basal-most clade in Boraginaceae s.str., and the fossils described here agree well with an assumed African origin of the family and the Boraginales I, providing an important additional calibration point for dating the phylogenies of this clade.

L’analyse du potentiel géologique de trois sites différents dans les Monts des Traras (Algérie) a permis d’étudier trois catégories de substances minérales non métalliques et qui sont le calcaire, le sable et l’argile. L’état actuel et les perspectives d’exploitation des trois sites, objet du présent travail, montre que les ressources disponibles sont importantes et plaide pour une exploitation à long terme optimale et économiquement rentable. L’analyse de laboratoire effectuée sur les substances montre leur grande utilité pour le marché local en matière d’argile, de sable et de granulats. Néanmoins, des lacunes en matière d'environnement ont été relevées. Mots-clés : Monts des Traras, Algérie, Calcaire, Sable, Argile, Exploitation, Ressources, Environnement. ABSTRACT The analysis of the geological potential of three different sites in the Traras Mountains (Algeria) permitted to study three categories of nonmetallic minerals, which are limestone, sand and clay. The current state and prospects of the three operating sites, object of the present work shows that the available resources are important and calls for long-term operating optimally and economically viable. The laboratory analysis of substances shows their great benefit to the local market in terms of clay, sand and aggregates. However, lacks in environmental matters were noted. Key-words : Traras Mountains, Algeria, Limestone, Sand, Clay, Operations, Resources, Environment. ملخص المتاحة لھا أھمیتھا، وتدعو إلى عملیة استغلال طویلة الأمد و الأمثل اقتصادیا. التحلیل المخبري للمواد تظھر فائدتھا الكبیرة للسوق المحلیة من حیث الطین، الرمل والحصى. مع ذلك، سجلت ثغرات تتعلق بالبیئة و المحیط في ھذا البحث. ساعد تحلیل إمكانیات الجیولوجیة من ثلاثة مواقع مختلفة في جبال " الترارة " لتحدید ثلاث فئات من المعادن اللافلزیة، والتي ھي : الحجر الجیري (الركام)، الرمل و الطین. الوضع الراھن وآفاق الاستغلال في المواقع الثلاثة التي یغطیھا ھذا العمل یدل على أن الموارد الكلمات الرئیسیة : جبال " الترارة "، الجزائر ، الحجر الجیري، الرمل، الطین، الاستغلال، الموارد، البیئة.