Search publications of the members of the Royal Belgian institute of natural Sciences
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A scientific name for Pacific oysters
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Bushmeat for sale in Brussels
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Identifying Invasive Alien Species by DNA-barcoding: possibilities, gaps and pitfalls
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Identifying mosquitoes (Diptera: Culicidae) from foreign deployment sites of the Belgian armed forces
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DNA-barcoding: an efficient tool for rapid identification of native and exotic mosquito species (Diptera: Culicidae) intercepted in Belgium
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The Devonian–Carboniferous boundary in Belgium and surrounding areas
- The Devonian–Carboniferous boundary is associated with a major extinction event of the Phanerozoic. It was also a time marked by a rapid but short-lasting change in deposition called Hangenberg Event. In the Namur–Dinant Basin the uppermost Devonian (‘Strunian’) deposits recorded a third-order transgression that produced a progressive switch from coastal siliciclastic to proximal mixed deposits with an increase of the carbonate production on the ramp. Hence, the Comblain-au-Pont and lower Hastière formations are considered as the transgressive system tract, whereas the middle member of the Hastière Formation is interpreted as the highstand system tract, capped by an erosion surface corresponding to the third-order sequence boundary. Superimposed on these third-order sequences are well-marked orbitally forced precession cycles (wet–dry climate alternations) of c. 18.6 ka, appearing as irregular c. 30–80-cm-thick couplets of limestone and calcareous shale beds. The Hangenberg Black Shale Event is locally present as dark shales that likely spread over the shelf, marking the maximum flooding surface of the sequence. Before and after this event, carbonate facies rich in benthic macrofauna and microfauna continued to develop. The Hangenberg Sandstone Event, appearing as a sandstone bed in pelagic sections, is variously recorded at the base of the Hastière Formation, either as a sandy siltstone bed in proximal sections or as a horizon with limestone clasts and reworked fossils in more distal settings. The Hangenberg Sandstone Event beds occur sharply in the stratigraphic record and do not correspond to the long sea level fall of a third-order sequence boundary, but most probably to a short out-of-sequence event. The revision of the stratigraphic distribution of major fossil groups pleads for a continuous biostratigraphic succession with no obvious hiatus. The variable development of some micropalaeontological zones at the end of the Devonian is the result of complex ecobiostratigraphic interactions with the environment rather than the reflection of true hiatuses. It is marked by extinctions of Devonian taxa, concomitantly with the end of the reworking produced by the Hangenberg Sandstone Event, most probably immediately below the entry of the conodont Protognathodus kockeli. It is also coincident with the boundary between the foraminiferal zones DFZ7–MFZ1, rugose coral zones RC0–RC1 and between the palynozones LE–VI. After the short-lasting regressive phase of the Hangenberg Sandstone Event, normal depositional settings returned with the deposition of the Hastière Formation. Hence, the end of the Hangenberg Sandstone Event is proposed as the most natural proxy to pinpoint the Devonian– Carboniferous boundary.
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A new basal ornithopod dinosaur from the Lower Cretaceous of China
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CHEMICAL PRESERVATION OF TAIL FEATHERS FROM ANCHIORNIS HUXLEYI, A THEROPOD DINOSAUR FROM THE TIAOJISHAN FORMATION (UPPER JURASSIC, CHINA)
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A new phylogeny of cerapodan dinosaurs
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A new titanosaur (Dinosauria: Sauropoda) from the Upper Cretaceous of Velaux-La-Bastide Neuve (southern France)
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Feather evolution in Pennaraptora
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Integumentary Structures in Kulindadromeus zabaikalicus, a Basal Neornithischian Dinosaur from the Jurassic of Siberia
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Data of feather recovering performance of birds and micro structure of pigeons’ feathers
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First annotated draft genomes of nonmarine ostracods (Ostracoda, Crustacea) with different reproductive modes
- Ostracods are one of the oldest crustacean groups with an excellent fossil record and high importance for phylogenetic analyses but genome resources for this class are still lacking. We have successfully assembled and annotated the first reference genomes for three species of nonmarine ostracods; two with obligate sexual reproduction (Cyprideis torosa and Notodromas monacha) and the putative ancient asexual Darwinula stevensoni. This kind of genomic research has so far been impeded by the small size of most ostracods and the absence of genetic resources such as linkage maps or BAC libraries that were available for other crustaceans. For genome assembly, we used an Illumina-based sequencing technology, resulting in assemblies of similar sizes for the three species (335–382 Mb) and with scaffold numbers and their N50 (19–56 kb) in the same orders of magnitude. Gene annotations were guided by transcriptome data from each species. The three assemblies are relatively complete with BUSCO scores of 92–96. The number of predicted genes (13,771–17,776) is in the same range as Branchiopoda genomes but lower than in most malacostracan genomes. These three reference genomes from nonmarine ostracods provide the urgently needed basis to further develop ostracods as models for evolutionary and ecological research.
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Effects of hydrocarbon extraction on freshwaters
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On the first Belgian record of the Eifelian (Middle Devonian) ammonoid cephalopod Subanarcestes (Suborder Anarcestina)
- Ammonoid cephalopods are extremely rare in the Lower and Middle Devonian sedimentary rocks of Belgium, which contrasts with the neighboring sedimentary basins. However, searches in old collections and recent collecting efforts show that ammonoids do occur in these beds in Belgium, which allows to enlarge our knowledge of Lower and Middle Devonian ammonoid occurrences. Here, a record of the Eifelian (Middle Devonian) anarcestid ammonoid genus Subanarcestes is described for the first time from Belgium based on a specimen from the Jemelle Formation (Chavées Member). This specimen was collected more than a century ago by Eugène Maillieux at Trou Bodet near Couvin. It laid unrecognized as an ammonoid cephalopod for many decades in the collections of the Royal Belgian Institute of Natural Sciences, while being previously identified as Cryptoceras or ‘Nautilus’ fossil, which if correct, constituted Belgium’s oldest Nautilida fossil. Micro-CT imaging greatly helped in the taxonomic assignment of the specimen.
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A Santonian record of the nautilid cephalopod Angulithes westphalicus (Schlüter, 1872) from the subsurface of the Campine, north-east Belgium, with comments on regional lithostratigraphic problems
- Newly recognised material of the Late Cretaceous nautilid Angulithes westphalicus is described from the subsurface of the eastern part of the Campine in north-east Belgium. This constitutes the first formal documentation of this genus and species from the Cretaceous of Belgium, having been identified amongst a large suite of fossils collected from the Voort Shafts I & II of the Zolder colliery during the first half of the twentieth century. The specimens originate from an interval of marine calcareous sand with a marly glauconiferous base, dated as late middle Santonian (Gonioteuthis westfalicagranulata belemnite Zone) and for which a deepening of the depositional environment is documented. Lithostratigraphically, the specimens occur within the Vaals Formation, within the upper part of the Asdonk Member or alternatively within the lower part of the Sonnisheide Member. The early Campanian age of the Asdonk Member suggested previously is refuted, the age of the Sonnisheide Member needs further study. The position of the siphuncle in A. westphalicus is illustrated for the first time; it is positioned closer to the venter than the dorsum, which confirms the close evolutionary relationship with Angulithes galea, which ranges from the upper Turonian to middle Coniacian in central Europe.
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The fossil bivalve Angulus benedeni benedeni: a potential seasonally resolved stable isotope-based climate archive to investigate Pliocene temperatures in the southern North Sea basin
- Bivalves record seasonal environmental changes in their shells, making them excellent climate archives. However, not every bivalve can be used for this end. The shells have to grow fast enough so that micrometre- to millimetre-sampling can resolve sub-annual changes. Here, we investigate whether the bivalve Angulus benedeni benedeni is suitable as a climate archive. For this, we use ca. 3-million-year-old specimens from the Piacenzian collected from a temporary outcrop in the Port of Antwerp area (Belgium). The subspecies is common in Pliocene North Sea basin deposits, but its lineage dates back to the late Oligocene and has therefore great potential as a high-resolution archive. A detailed assessment of the preservation of the shell material by micro-X-ray fluorescence, X-ray diffraction, and electron backscatter diffraction reveals that it is pristine and not affected by diagenetic processes. Oxygen isotope analysis and microscopy indicate that the species had a longevity of up to a decade or more and, importantly, that it grew fast and large enough so that seasonally resolved records across multiple years were obtainable from it. Clumped isotope analysis revealed a mean annual temperature of 13.5 ± 3.8 ∘C. The subspecies likely experienced slower growth during winter and thus may not have recorded temperatures year-round. This reconstructed mean annual temperature is 3.5 ∘C warmer than the pre-industrial North Sea and in line with proxy and modelling data for this stratigraphic interval, further solidifying A. benedeni benedeni's use as a climate recorder. Our exploratory study thus reveals that Angulus benedeni benedeni fossils are indeed excellent climate archives, holding the potential to provide insight into the seasonality of several major climate events of the past ∼ 25 million years in northwestern Europe.
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New data on the Devonian and Carboniferous Graptolithina (Dendroidea) from Belgium with notes on possible occurrences of Rhabdopleuridae in the Belgian Carboniferous
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The LASUGEO project:monitoring LAnd SUbsidence caused by Groundwater exploitation through gEOdetic measurements.
- In the last decades, rapid urbanization, global climate change and uncontrolled anthropogenic transformations of the territory caused a relevant increase in geo-hazards events with huge economic and social consequences. The dramatic increase of these events with environmental degradation highlights the importance of improving ground monitoring and natural resources management with a continuous exchange of knowledge between the scientific community and authorities in charge of environmental risk management. Since the late 1990s, SAR (Synthetic Aperture Radar) data allow measuring slow-moving ground deformations. In the last decades, the use of spaceborne InSAR (Interferometric SAR) has increased significantly thanks to the availability of large-area coverage, millimetre precision, high spatial/temporal data resolution and good cost-benefit. For the last 3 decades, the development of Multi-Temporal Interferometric SAR techniques (MT-InSAR), commonly grouped into PSI-like (Persistent Scatterers Interferometry) and SBAS-like (Small BAseline Subset) algorithms, has changed the way radar images can be exploited for geohazard monitoring (natural gas extraction, mining activities, groundwater overexploitation, karst or landslides processes, etc.). Most of the subsidence bowls mapped by the PSI technique in Belgium have been related to strong fluctuations of an aquifer implying at the surface ground deformations (Declercq et al., 2017; 2021). Besides, the recent dry years are related to ground stability problems in large areas of Flanders. Land subsidence poses significant problems. The most affected regions lie on compressible loose sediments. Any change in the piezometric heads modifies the pore pressure, which may induce consolidation if the geological formations are compressible. Geomechanical aspects are fully coupled to groundwater flow equations. If groundwater levels and pressures are restored, a partial rebound (uplift) corresponding to the elastic part of the geological formations is observed. Consolidation and elastic rebound processes occur in confined and unconfined conditions. The most sensitive parts of the concerned aquifers contain clay, loam or peat lenses but consolidation may occur mostly in the underlying and overlying layers that are often less permeable and more compressible than the aquifer itself. In this case, it is largely a delayed process occurring as far as the pore pressure variation slowly propagates in the low permeability (aquitard) layers. We propose to confront the results of the PSinSAR technique data with hydrogeological groundwater models and two other geodetic techniques: GNSS and gravimetry. LASUGEO Geologica Belgica Meeting 2021, September 15-18, Tervuren, Belgium – Abstract Book, p. 75 focusses on ground deformations in different areas in Belgium: the deep aquifer system of western Flanders, the Tertiary aquifer system in Central Flanders, the Antwerp area, the Leuven area and the Brussels Region. The possible groundwater overexploitation needs to be established through a transient hydrogeological model considering all the stress factors applied to the aquifers. The estimated compaction in the subsiding bowls will be compared with 1D geomechanical model results. The latter will be performed using geotechnical effective stresses as deduced from the pore pressure distribution from the hydrogeological model (Dassargues et al., 1989). These different steps will be done by the partners of the LASUGEO project that are involved in the different case study areas.
