-
Raman spectroscopy as a tool to characterize heterogenite (CoO·OH) (Katanga Province, Democratic Republic of Congo).
-
Natural heterogenite (CoO·OH) samples were studied by Raman microspectroscopy, electronic microprobe and Electronic BackScattered Diffraction (EBSD). Raw samples and polished sections were made from 10 mines covering the Katanga copperbelt (Katanga Province, Democratic Republic of Congo). Four typical Raman responses have been obtained leading to investigate the laser-induced dehydroxylation of heterogenite into a Co-spinel structure. The results are also compared with EBSD patterns from oven heated heterogenite samples. A close relationship was established between the chemical substitutions of Co by mainly Cu, Ni, Mn and Al and their impact on the mineral Raman response.
Located in
Library
/
RBINS Staff Publications
-
Biodiversity in mountain groundwater: the Mercantour National Park as a European hotspot
-
Abstract Mercantour National Park (France) is recognized as a highly heterogeneous region with extremely varied geology, geomorphology and climatology, resulting in an exceptional biodiversity. From a hydrogeological point of view, it is also an area organized of small and discontinuous aquifers, their obligate groundwater fauna remaining absolutely unknown. This work explores the species richness of groundwaters in Mercantour National Park, using a sampling design at the catchment (six major valleys) and aquifer scales (aquifers in consolidated rocks and unconsolidated sediments). A major finding of this study is the discovery of 44 species restricted to groundwater, from which 43 are new to the Park and 10 are new to Science. Although a relatively small number of sites were sampled (53), the area may be considered as a new hotspot of groundwater biodiversity at the European level. The particular structure of the groundwater network, the high environmental heterogeneity of the region, and its Mediterranean position may explain such a high biodiversity. Species rarefaction curve showed that many species have yet to be discovered in groundwater of the Mercantour National Park. With more than 78% of species collected in the hyporheic zone, this study also highlights the importance of porous aquifers in sustaining groundwater biodiversity of mountainous regions. Key words: groundwater invertebrates, stygobionts, biodiversity hotspot, Mercantour National Park, hyporheic zone, spring. Résumé Biodiversité dans les eaux souterraines de montagne. Le Parc National du Mercantour: un ‘hotspot’ européen. Le Parc National du Mercantour est une région physiquement très hétérogène, avec des faciès géologiques, géomorphologiques et climatologiques extrêmement variés, à l’origine d’une biodiversité exceptionnelle. D'un point de vue hydrogéologique, son réseau souterrain est organisé en aquifères discontinus et de petite taille, dont la faune aquatique (stygobie) est aujourd’hui inconnue. Ce travail explore la richesse spécifique des eaux souterraines du Parc National du Mercantour, après la mise en œuvre d'un plan d'échantillonnage prenant en compte l'hétérogénéité environnementale à l’échelle du bassin versant (six vallées majeures) et de l'aquifère (aquifère fissuré ou poreux). Le premier fait marquant est la récolte de 44 espèces stygobies, 43 étant nouvelles pour le parc et 10 nouvelles pour la Science. Sur la base d’un nombre relativement faible de sites (53), cette zone peut être considérée comme un nouveau ‘hotspot’ de biodiversité des eaux souterraines à l'échelle européenne. La structure particulière du réseau hydrogéologique, l'hétérogénéité environnementale élevée, et la position méditerranéenne de cette région, pourraient expliquer une telle biodiversité. La courbe de raréfaction des espèces montre que nos connaissances sur le Mercantour sont néanmoins loin d'être complètes et que de nombreuses espèces restent encore à découvrir. Avec plus de 78 % des espèces récoltées dans la zone hyporhéique, ce travail souligne également le rôle des aquifères poreux, dans le maintien de la biodiversité des eaux souterraines de montagne. Mots-clés: invertébrés souterrains, stygobies, ‘hotspot’ de biodiversité, Parc National du Mercantour, zone hyporhéique, source.
Located in
Library
/
RBINS Staff Publications
-
Leaf litter copepods from a cloud forest mountain top in Honduras (Copepoda: Cyclopidae, Canthocamptidae)
-
Located in
Library
/
RBINS Staff Publications
-
Biodiversity of Belgian groundwaters and characterization of their stygobiotic fauna from a historical and ecological perspective
-
Located in
Library
/
RBINS Staff Publications
-
Biodiversity of Belgian groundwater fauna in relation to environmental conditions
-
1. The Pleistocene glaciations during the Quaternary appear to have resulted in an impoverished groundwater fauna in northern Europe. Re-colonisation may have occurred either through long-distance dispersal from unglaciated southern areas or from local refugia. 2. The Belgian groundwater fauna was sampled at multiple sites, and its habitats characterised, to assess whether the composition of present-day stygobiotic assemblages can be attributed to either of these mechanisms. 3. A total of 202 sampling sites were selected in four hydrogeographic units of the Meuse River catchment. Sites were equally divided among the saturated and unsaturated zones of fractured aquifers (karst) and within the hyporheic and phreatic zones of porous aquifers. Seventeen environmental parameters were determined in parallel. 4. More than 140 species were recorded, including representatives of the Amphipoda, Cladocera, Copepoda, Hydrachnidia, Isopoda, Oligochaeta, Ostracoda, Mollusca, Syncarida and Nematoda. Thirty stygobiont specieswere identified, of which10 species were new to the Belgian fauna, raising the total number of stygobiotic species in Belgium to 41. 5. The frequency of occurrences of stygobiotic species was always low, with 37% of the sampled sites lacking stygobionts. A few species were exclusive to one hydrological zone, although no statistically significant differences were detected in species richness at any of the four hierarchial levels considered (Meuse catchment = region, hydrogeographic units, aquifer type and hydrological zone). 6. Overall, results suggest that the stygobiotic fauna of Belgium is species-poor and mostly comprises widely distributed species with broad ecological tolerances. This supports the view that eurytopic species re-colonised the area by long-distance dispersal from refugia in southern Europe. The virtual absence of endemic species further suggests that the scenario of an ancient fauna that survived in local refugia is of minor importance.
Located in
Library
/
RBINS Staff Publications
-
Polygyny and strong genetic structuring within an isolated population of the wood ant Formica rufa.
-
Located in
Library
/
RBINS Staff Publications
-
Focus stacking: Comparing commercial top-end set-ups with a semi-automatic low budget approach. A possible solution for mass digitization of type specimens
-
Located in
Library
/
RBINS Staff Publications
-
Early Eocene cambaytheres from Indo-Pakistan are the sister group of Perissodactyls
-
Cambaytherium, Nakusia, and Kalitherium are closely related early Eocene mammals from the Indo-Pakistan region that have been assigned to Perissodactyla (Laurasiatheria)or Anthracobunidae. The latter have been variously considered artiodactyls or perissodactyls, but more recently are usually placed at the base of the order Proboscidea or of the more inclusive Tethytheria (Afrotheria). We present new evidence from the dentition, skull, and postcranial skeleton of Cambaytherium, from Gujarat, India (ca. 54.5 Ma), that cambaytheres occupy a pivotal position as the sister taxon of Perissodactyla. Cambaytherium was more robust than basal perissodactyls such as ″Hyracotherium″ and Homogalax, and had a body mass of ~25-27 kg based on humeral, radial, and dental regressions. Perissodactyl synapomorphies include a transverse nasal-frontal suture, twinned molar metaconids, and an astragalus with deeply grooved trochlea and a saddleshaped navicular facet. Like perissodactyls, cambaytheres are mesaxonic and have hooflike unguals and a cursorially-adapted skeleton. Plesiomorphic traits compared to basal perissodactyls include bunodont molars with large conules and almost no hint of bilophodonty, unmolarized premolars, sacrum with four vertebrae, humerus with distally extensive pectoral crest and distal articulation lacking a capitular tail, distal radius without discrete scaphoid and lunate fossae, femur with low greater trochanter, calcaneus robust and wide with rounded ectal facet, astragalus wide with moderately long neck and vestigial astragalar foramen, navicular and cuboid short and wide, metapodials short and robust, and Mc I and Mt V present. In most or all of these traits cambaytheres are intermediate between phenacodontid condylarths and perissodactyls but closer to the latter. Our phylogenetic analyses place cambaytheres just outside perissodactyls, and place anthracobunids among primitive perissodactyls. However, similarities between cambaytheres and anthracobunids suggest that they are closely related, and future discovery of skeletal material of anthracobunids will provide a test of this hypothesis. Our results indicate that Anthracobunidae are not Proboscidea or tethytheres, and suggest that the origin of Perissodactyla may have taken place on the drifting Indian plate. How the progenitors of perissodactyls reached India is more problematic but might have involved land connections with Afro-Arabia during the Paleocene. Field work and research supported by the National Geographic Society.
Located in
Library
/
RBINS Staff Publications
-
Paleobiogeography of the lotus plant (Nelumbonaceae: Nelumbo) and its bearing on the paleoclimatic changes
-
The historical reconstruction of the origin and dispersal of plant taxa in space and time facilitates a better understanding of theirmodern distribution patterns. However,most studies of paleobiogeography have focused on terrestrial plants, and the distribution changes of aquatic plants are less well understood. Here we study the lotus plant Nelumbo (Nelumbonaceae), an aquatic perennial herb, with a disjunctive distribution across East, South and Southeast Asia-North Australia and North America. The reproductive organs of Nelumbo changchangensis He et Jin from the Eocene of Hainan, China are supplementarily described. Analysis of the spatial and temporal distributions of Nelumbo in the geologic past indicates that the genus first occurs in mid-latitude area of Laurasia in the Early Cretaceous, then becomeswidespread in North America and Eurasia and expands into SouthAmerica during the Late Cretaceous, and reaches its maximum northern limit during the Eocene. The genus persists and thrives in North America and Eurasia until the Pliocene. The Pleistocene ice age causes the extinction of Nelumbo in Europe and central Asia, and its populations in North American and Asia are also restricted to refuges of lower latitude. Like the terrestrial plants Metasequoia (Cupressaceae) and Nordenskioeldia (Trochodendraceae), the fluctuations of Nelumbo distribution ranges are also linked to climatic changes in the Cenozoic. The cooling climate and increasing seasonality in the Eocene of East Asia may favor the origin of tubers and the differentiating of the ecotypes in lotus, which allow the deciduous type to survive in cold winters.
Located in
Library
/
RBINS Staff Publications
-
A new kogaionid multituberculate mammal from the Maastrichtian of the Transylvanian Basin, Romania
-
Abstract: The Latest Cretaceous (Maastrichtian) terrestrial sedimentary sequences of the Hateg Basin in Transylvania are well known for the so-called “Hateg Island” vertebrate faunas, which evolved in endemic (insular?) conditions. In addition to frogs, lizards, turtles, crocodilians, birds and dinosaurs, peculiar multituberculate mammals have been recorded, all belonging to the family Kogaionidae. Here, a new species of the genus Barbatodon is reported from the Maastrichtian S¸ ard Formation in the Transylvanian Basin (Alba County, Romania). Barbatodon oardaensis n. sp. is characterized by M1 cusp formula 3:4:2 and is much smaller than the two other Maastrichtian kogaionids from Transylvania, Barbatodon transylvanicus and Kogaionon ungureanui. The origin and paleobiogeography of kogaionids are discussed. Résumé: Les séquences continentales du Crétacé terminal (Maastrichtien) du bassin de Hateg en Transylvanie sont réputées pour leurs faunes de vertébrés originaires de « l’île de Hateg », qui ont évolué dans des conditions endémiques (insulaires ?). Hormis des grenouilles, lézards, tortues, crocodiles, oiseaux et dinosaures, des mammifères multituberculés particuliers ont également été mentionnés, tous appartenant à la famille des Kogaionidae. Une nouvelle espèce du genre Barbatodon est décrite dans le Maastrichtien de la Formation de S¸ ard, dans le bassin de Transylvanie (district d’Alba, Roumanie). Barbatodon oardaensis n. sp. est caractérisée par une formule dentaire de M1 3:4:2 et est plus petite que les deux autres kogaionidés de Transylvanie, Barbatodon transylvanicus et Kogaionon ungureanui. L’origine et la paléobiogéographie des kogaionidés sont discutées.
Located in
Library
/
RBINS Staff Publications
