Office National des Mines ONM

Tunis, Tunisia

Office National des Mines ONM

Tunis, Tunisia
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Ravel A.,Montpellier University | Adaci M.,Abou Bekr Belkaid University Tlemcen | Bensalah M.,Abou Bekr Belkaid University Tlemcen | Mahboubi M.,Oran University of Science and Technology - Mohamed Boudiaf | And 10 more authors.
Journal of Systematic Palaeontology | Year: 2015

Among the Afro-Arabian Palaeogene chiropterans, philisids were the most common and diversified members. The Philisidae are considered as an extinct primitive group of Vespertilionoidea, a well-diversified superfamily that today includes Natalidae, Molossidae and Vespertilionidae. However, the position of Philisidae within this superfamily has never been clearly established. These bats are characterized by a very distinctive dental morphology, and include some representatives that were among the largest bats to be known. Here we describe new dental remains attributable to philisids from the Early-Middle Eocene of Chambi, Tunisia and Gour Lazib area, Algeria. These fossils allow us to reconsider the dental morphology of the oldest philisids: Dizzya exsultans Sigé, 1991 and Witwatia sigei Ravel, 2012. We have undertaken a cladistic assessment of the dental evidence (47 dental and mandible characters) to clarify the phylogenetic relationships within Philisidae, and its position within Vespertilionoidea, in order to highlight the origin, historical biogeography and patterns of dispersion of the most diversified extant bat group. The specialized dental morphology of philisids implies particular occlusion seen in the three-dimensional reconstructions of teeth of Witwatia sigei and Dizzya exsultans. The peculiar morpho-functional anatomy of the teeth and the large size of these bats were well adapted to an opportunistic diet, and probably contributed to the early success of the family in North Africa. © 2014 The Trustees of the Natural History Museum, London.

Ravel A.,Montpellier University | Adaci M.,Abou Bekr Belkaid University Tlemcen | Bensalah M.,Abou Bekr Belkaid University Tlemcen | Charruault A.-L.,Montpellier University | And 9 more authors.
Geodiversitas | Year: 2016

This study focuses on new fossil faunas of bats discovered in North Africa following several field campaigns. The fossiliferous localities include those from the Early to Middle Eocene of Tunisia (Chambi) and Algeria (Glib Zegdou). Systematic and cladistic analyses carried out on the fossil material, primarily including isolated teeth, allow us to highlight the modalities of the radiation of the first modern microbats. These new faunas include eight well-identified new taxa belonging to five modern families: one Necromantidae (?Necromantis fragmentum Ravel, n. sp.), two Hipposideridae Miller, 1907 (?Palaeophyllophora tunisiensis Ravel, n. sp. and Hipposideros [Pseudorhinolophus] africanum Ravel, n. sp.), three Emballonuridae Gervais in de Castelnau, 1855 (Vespertiliavus kasserinensis Ravel, n. sp., ?Vespertiliavus aenigma Ravel, n. sp., and Pseudovespertiliavus parva Ravel n. gen., n. sp.), one Nycteridae (Khoufechia gunnelli Ravel n. gen., n. sp.) and an undetermined Vespertilionidae. Two other taxa are identified (Chambinycteris pusilli Ravel n. gen., n. sp. and Drakonycteris glibzegdouensis Ravel n. gen., n. sp.), but they show an original dental pattern which precludes a family attribution. Two cladistic analyses allow to clarify the phylogenetic position of the best documented taxa. The results highlight for Hipposideridae and Emballonuridae chiropterans a major dispersal axis from North Africa towards South Europe during the Middle Eocene. © Publications scientifiques du Muséum national d’Histoire naturelle, Paris.

Marivaux L.,Montpellier University | Ramdarshan A.,Montpellier University | Essid E.M.,Office National des Mines ONM | Marzougui W.,Office National des Mines ONM | And 6 more authors.
PLoS ONE | Year: 2013

Background: Molecular clock estimates of crown strepsirhine origins generally advocate an ancient antiquity for Malagasy lemuriforms and Afro-Asian lorisiforms, near the onset of the Tertiary but most often extending back to the Late Cretaceous. Despite their inferred early origin, the subsequent evolutionary histories of both groups (except for the Malagasy aye-aye lineage) exhibit a vacuum of lineage diversification during most part of the Eocene, followed by a relative acceleration in diversification from the late Middle Eocene. This early evolutionary stasis was tentatively explained by the possibility of unrecorded lineage extinctions during the early Tertiary. However, this prevailing molecular view regarding the ancient origin and early diversification of crown strepsirhines must be viewed with skepticism due to the new but still scarce paleontological evidence gathered in recent years. Methodological/Principal Findings: Here, we describe new fossils attributable to Djebelemur martinezi, a≈50 Ma primate from Tunisia (Djebel Chambi). This taxon was originally interpreted as a cercamoniine adapiform based on limited information from its lower dentition. The new fossils provide anatomical evidence demonstrating that Djebelemur was not an adapiform but clearly a distant relative of lemurs, lorises and galagos. Cranial, dental and postcranial remains indicate that this diminutive primate was likely nocturnal, predatory (primarily insectivorous), and engaged in a form of generalized arboreal quadrupedalism with frequent horizontal leaping. Djebelemur did not have an anterior lower dentition as specialized as that characterizing most crown strepsirhines (i.e., tooth-comb), but it clearly exhibited a transformed antemolar pattern representing an early stage of a crown strepsirhine-like adaptation ("pre-tooth-comb"). Conclusions/Significance: These new fossil data suggest that the differentiation of the tooth-comb must postdate the djebelemurid divergence, a view which hence constrains the timing of crown strepsirhine origins to the Middle Eocene, and then precludes the existence of unrecorded lineage extinctions of tooth-combed primates during the earliest Tertiary. © 2013 Marivaux et al.

Merzeraud G.,Montpellier University | Essid E.M.,Office National des Mines ONM | Marzougui W.,Office National des Mines ONM | Ammar H.K.,Office National des Mines ONM | And 4 more authors.
Bulletin de la Societe Geologique de France | Year: 2016

The Kasserine area, in central Tunisia, is for a long time considered by many authors as an emerged island (or islets), since the upper Cretaceous until the middle Miocene. In the eighties, continental deposits were described and dated Eocene. At that time, no marine deposit older than middle Miocene were thus known in central Tunisia, and the only Eocene marine strata, were located in periphery of the emerged zone, in phosphatic basins. It is in the area of Djebel el Kebar, which is situated at the eastern edge of the Kasserine region that a detailed study of the Eocene-middle Miocene deposits was carried out. In the studied series, four major unconformities are observed and correlated on the whole of the site. Between these surfaces, three successive sedimentary units are observed from base to top and are composed of limestone, glauconite and clay deposits (unit I), shell beds limestone (unit II), conglomerate, sandstone and silty-clay (unit III). Paleontological and biostratigraphic results. - An important fossils locality was discovered in Djebel el Kebar, in glauconitic marine deposits of the first sedimentary unit. Fauna, very rich, contains many marine (shark, ray, sirenian, etc.) and continental forms (rodent, hyracoid and primate). The new dating clearly indicates that the deposits of the lower part of the series are Bartonian in age. Sedimentological results. - Thirteen facies were identified and the exceptional conditions of outcrop in Djebel el Kebar have allowed us to map the lateral facies evolution. The sedimentary environments were reconstituted and their succession shows a very shallow water-depth carbonate platform (wave dominated and influenced by storms and tide), passing upward into a sandy fluvial and estuarine environment. Tectono-sedimentary and sequential evolution. - A sequence stratigraphie framework was proposed, in which, on both sides of unconformities primarily of tectonic origin, three very partially preserved sequences (> 3 Ma) are compatible with the second order of Vail et al. [1991]. In these sequences, the major part of the studied series is set up in transgressive system tracts and highstand system tracts. The fossil locality then seems to be associated with several episodes with condensation, formed during the transgressive part of the second order cycle. Conclusions. - The first, new and important result of this work, is the characterization and dating of marine deposits older than middle-Miocene in Djebel el Kebar, in central Tunisia. The studied area is thus not in the emerged part of the zone of Kasserine during the Eocene. Between Bartonian and lower-Miocene, marine facies, evolve within an environment of very shallow marine carbonated platform. A major event (flexure coupled with eustatic fall in Miocene) would cause a change of depositional profile, the arrival of coarse terrigenous material and the installation of a continental fluvial and estuarine sedimentary environment. Finally the whole of the series records large scale tectono-eustatic changes, responsible of several second order sequences, partially preserved.

Marivaux L.,Montpellier University | Essid E.M.,Office National des Mines ONM | Marzougui W.,Office National des Mines ONM | Khayati Ammar H.,Office National des Mines ONM | And 3 more authors.
Zoologica Scripta | Year: 2015

The Late Early-to-Early Middle Eocene Zegdoumyidae are the oldest representatives of the order Rodentia to be known in Africa thus far. Despite the fragmentary nature of their fossil record, these early African rodents have been central in discussions surrounding the early evolutionary history of the Anomaluroidea clade (the living forms of which are the 'scaly-tailed squirrels', i.e. Anomaluridae). Here, we describe new dental remains attributable to Zegdoumys sbeitlai, a zegdoumyid from Tunisia (Djebel Chambi, CBI-1) dated at ca 50-45 Ma. The original material referred to this taxon was limited to four teeth documenting few dental loci. The new gathered material comprises practically all dental loci (except P4), thereby allowing a better description and characterization of this taxon. This Tunisian species is clearly distinct from its roughly coeval Algerian counterpart (Z. lavocati) or from the younger species recorded from Namibia (Z. namibiensis). We investigated the phylogenetic positions of Z. sbeitlai and the Zegdoumyidae in a high-level rodent phylogeny with a cladistic assessment of the dental evidence. Our results show that zegdoumyids represent the earliest offshoots (pectinately arranged) of a large clade that also encompasses the more advanced Eocene anomaluroids (here named Nementchamyidae), the Miocene Nonanomaluridae, and the stem and crown Anomaluridae. In this phylogenetic context, the species of Zegdoumys are the basalmost members of this large Anomaluroidea clade. Zegdoumyid taxa are therefore the oldest stem anomaluroid candidates, a statement which strengthens support for the hypothesis of the great antiquity of the Anomaluroidea clade in Africa. From a historical biogeography perspective, this assumption suggests that anomaluroids invaded Asia from Afro-Arabia sometime during the Middle Eocene, a dispersal event which was likely concomitant but opposite to the dispersals envisaged for the hystricognathous rodents and anthropoid primates from Asia to Afro-Arabia. © 2015 Royal Swedish Academy of Sciences.

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