Search publications of the members of the Royal Belgian institute of natural Sciences
-
A survey of perciform otoliths and their interest for phylogenetic analysis, with an iconographical synopsis of the Percoidei
-
Fish otoliths from the Matthews Landing Marl Member (Porters Creek Formation), Paleocene of Alabama
-
Fish otoliths as paleobathymetric indicators
-
Fish otoliths from the Late Oligocene (Eger and Kiscell Formations) in the Eger area (northeastern Hungary)
-
First record of fossil Merlangius (Pisces, gadiformes) from Alaska and chronostratigraphic implications
-
First virtual endocasts of the Paleocene arctocyonids Arctocyon and Chriacus: Insight into the behavior of early placental mammals after the end-Cretaceous mass extinction
- The vacant niches left by the non-avian dinosaurs and other vertebrates after the end-Cretaceous mass extinction, provided a crucial opportunity for placental mammal diversification. The general neurosensory organization exhibited by extant mammals has been maintained since the Late Triassic-Early Jurassic. Much later during the Eocene, fossils of early members of extant placentals display neurosensory innovations, such as a proportionally larger neocortex and a higher encephalization quotient (EQ), compared to their Mesozoic ancestors. However, few studies have focused on the brain of the oldest placentals that lived during the Paleocene. We analysed the neurosensory system of two species of arctocyonid ‘condylarths’, a likely nonmonophyletic group, including some species potentially implicated in the origins of extant ungulates. ‘Arctocyonids’ were of small-to-medium size, omnivorous and mainly terrestrial. We obtained cranial and bony labyrinth endocasts for Arctocyon and two species of Chriacus using high-resolution computed tomography. Both species exhibit plesiomorphic features shared with other early Paleocene mammals such as a relatively small lissencephalic brain with an EQ range of 0.07-0.31 using Eisenberg’s equation. The olfactory bulbs and the petrosal lobules represent 7% and less than 1% of the total endocranial volume, respectively. The neocortical height represents ~25% of the total endocranial height. Based on the cochlea, these species had hearing capabilities similar to extant wild boars. Agility scores between 2 and 3, show that these taxa were similar to the American badger and the crab-eating raccoon, suggesting that Arctocyon and Chriacus were moderately agile. These results support the growing evidence that early placentals had low EQs and less expanded neocortices compared to Eocene and later taxa, potentially indicating that complex neurosensory organization was not key to the placental radiation after the end-Cretaceous mass extinction. This research has been funded by Marie Sklodowska-Curie Actions: Individual Fellowship, European Research Council Starting Grant, National Science Foundation, and Belgian Science Policy Office.
-
An early Eocene mammal assemblage from Bayan Ulan (Inner Mongolia, China) and reassessment of the Arshantan Land Mammal Age
- Paleogene mammal localities are particularly well represented in the area of Erlianhot, Inner Mongolia. Among them, the locality of Bayan Ulan is most famous for its late Paleocene Gashatan fauna. The Arshantan fauna of the site is not well known, since no extensive study has been done so far. Here we present a mammal assemblage based on dental and tarsal material from a new Arshantan collection resulting from excavations done by a Belgian-Chinese expedition in Inner Mongolia in 1995 – retrieved from the red beds of the late early to early middle Eocene Arshanto Formation at Bayan Ulan. It consists of at least six different taxa: the primitive lagomorph Dawsonolagus antiquus, the large pantodont Pantolambdodon sp., the lophialetid tapiroid Schlosseria magister, the rhinocerotoid Hyrachyus crista, and a new smaller rhinocerotoid. The latter is closely related to the genera Yimengia and Rhodopagus. The species exhibits transverse Hunter-Schreger bands, no reduction of the lower premolars, m3 has no hypoconulid, and P4 bears a continuous “V”-shaped protolophmetaloph loop. The Arshantan assemblage at Bayan Ulan is dominated by small perissodactyls, represented by extensive lower and upper dentition as well as foot bones. Also, for the first time, p4-m1 of Dawsonolagus antiquus, tarsal material from Pantolambdodon, and lower dentition of Hyrachyus crista are illustrated. Unlike other described Arshantan faunas, the Bayan Ulan Arshantan mammal assemblage has been collected exclusively from a single locality, which allows it to be used in the reassessment of the Arshantan Land Mammal Age. This research has been funded by project MO/36/011 and bilateral cooperation project BL/36/C12 of the Belgian Federal Science Policy Office.
-
The Paris Basin Sparnacian: Revision of the lithostratigraphic nomenclature thanks to new sedimentary, mineralogical, chemo- and bio-stratigraphic data
- In the Paris Basin, marine deposits of the Vesles and Montagne de Laon Groups bracket terrestrial to littoral litho-units of the Mont Bernon Group. Since 2007, we study those Sparnacian facies, as they record the effects of a climate crisis linked to a massive release of greenhouse gases into the atmosphere. This hyperthermal event, the Paleocene Eocene Thermal Maximum (PETM), occurred 55.8 Ma ago, was brief (170 ka) and intense (+ 5 to 8°C vs. baseline). Studied as an analogue to the current global warming, it is marked by a negative isotopic excursion of 2 to 6 ‰ of the δ13C and coincides with environmental perturbations. About thirty reference successions have been studied, to which well-described information is incorporated, providing a comprehensive and detailed set of geological data. The aim is to 1) revise the lithostratigraphic nomenclature by integrating new δ13Corg and biostratigraphic data, 2) establish well-calibrated correlations in these series prone to hiatuses and lateral facies changes, 3) build a robust framework to reconstitute and discuss the evolution of landscapes, flora and fauna. We show a prominent record of the PETM over 15-25 m, marked by a strong increase in the sedimentation rate. Steps identified in the δ13Corg curves enable fine correlation, 1) especially at the beginning of the event in fluvial and more rarely lagoonal to lacustrine environments, 2) then in alluvial plains, with development of calcretes and variegated paleosols, 3) and in swamps, lakes and lagoons, formed in a context of rising waterlevel. We further observe faunal and floral turnovers, eutrophication of aquatic environments, extreme acme of Apectodinium and few other dinoflagellate cyst groups as well as the occurrence of new dinoflagellate species. Lateral facies variations are anchored and paleogeographic maps drawn. It appears that some lithounits previously considered as unique in the Paris Basin (e.g. lignite, plastic clay, fluvial sand, lacustrine limestone and lagoonal sediments) are not synchronous and cannot be regarded as stratigraphic markers for a unique event. This work has been funded by the Regolith and RGF programs of the BRGM, the French Research and Higher Education Ministry and the Belgian AFICI 08-1911 and BR/121/A3/PALEURAFRICA projects.
-
Eocene fossil dermochelyid provides insights into why leatherback turtles “want to become” marine mammals
- Leatherbacks constitute a bizarre clade of marine turtles today represented by a single species, Dermochelys coriacea. A series of peculiar physiological adaptations and behaviors make this species particularly reminiscent to some marine mammals. These include particularly advanced skeleton adaptations for swimming, the largest body size among living reptiles, highly elevated growth and metabolic rates, and coldwater tolerance, which enable D. coriacea to lead a truly pelagic, highly migratory, cosmopolitan lifestyle. It is one of the deepest diving animal today, which aids searching for its almost exclusive prey of jellyfishes. Due to their pelagic lifestyle and reduced skeleton, however, the fossil record of leatherbacks is very poor. Here we evaluate the skeletal anatomy of Eosphargis gigas from the Ypresian of Belgium, represented by one of the earliest and most completely preserved fossil dermochelyid. E. gigas already shows several of the anatomical specializations of the extant leatherback but it is primitive in retaining a more ossified shell. The autapomorphic rugose surface decoration of the dermal skull indicates high degree of vascularization, which in turn likely aided regulation of acid–base balance relating to hypercapnia (excess blood carbon dioxide) and/or lactate acidosis based on modern and fossil analogies. Both type of acidosis typically occurs during diving and thus E. gigas likely had deep diving capabilities, which is consistent with its postcranial skeleton. The jaw apparatus also shares many specializations with D. coriacea that may represent adaptation for preying on jellyfish. The emerging hypothesis is that the skeletal and physiological adaptations of leatherbacks are all related to feeding specializations and associated deep diving. Many of these evolved early in the lineage under greenhouse climatic conditions with the likely associated deeper placement of the gelatinous plankton zone compared to icehouse conditions. This study was supported by the SYNTHESYS program (grants AT-TAF 1441, FR-TAF 4290, GB-TAF 1882, BE-TAF 5292); Train2Move-Marie Curie Fellowship awarded to M.R.
-
A new basal raoellid artiodactyl (Mammalia) from the middle Eocene Subathu Group of Rajouri District, Jammu and Kashmir, northwest Himalaya, India
- A new artiodactyl of moderate size is described on the basis of several dentaries and maxillae from the middle Eocene Subathu Group of the Kalakot area, Rajouri District, Jammu and Kashmir, India. Despite its general resemblance with the family Dichobunidae this taxon shares with Raoellidae two unambiguous characters: the presence of a hypoconulid on p4, and an asymmetrical P4. The position of the new taxon within the Cetacea / Raoellidae clade is strongly supported by eight non ambiguous synapomorphies, among which a cristid obliqua on lower molars anteriorly pointing towards the postectoprotocristid, and a P3 with only two roots. The new taxon is characterised by the following characters: a long symphysis; p3 and p4 with small parastylid and metastylid but no metaconid; lower molars with metaconid as the highest cusp, voluminous hypoconid, and absence of ‘hypolophid’; m1 and m2 with small paraconid, basally fused with metaconid, and small bifid tubercle-like hypoconulid; m3 with a crestiform paraconid; P3 and P4 with small protocone and shelf-like cingulae; upper molars with small paraconule and large metaconule (pseudohypocone); M1 and M2 with conical brachydont cusps; M3 with bunodont bulbous cusps; cristae and cingulae distinct and thick, presence of an ectoloph. The presence of a new primitive raoellid in the middle Eocene Subathu Group sheds new light on the phylogeny and paleobiogeography of basal raoellid artiodactyls. This work is partly funded by project BR/121/A3/PALEURAFRICA from the Belgian Science Policy Office.
-
ICES Viewpoint background document: Impact from exhaust gas cleaning systems (scrubbers) on the marine environment (Ad hoc).
- New global standards on sulphur content in marine fuels have led to an increasing number of ships installing exhaust gas cleaning systems, also known as scrubbers, to reduce air emissions of sulphur oxides. Ships equipped with a scrubber can continue to use heavy fuel oil, resulting in significant discharge of acidified water containing several contaminants, such as heavy metals, persistent organic pollutants (POPs; mainly polycyclic aromatic hydrocarbons), and nitrogen compounds.The simplest and most common type of scrubber system, the open-loop scrubber, directly discharges the contaminated water in to the sea. The use of scrubber systems by ships is an emerging global problem and an additional pressure on the marine environment. The substances found in scrubber discharge water can cause acute effects on marine biota and may have further impacts, through bioaccumulation, acidification, and eutrophication, on the structure and functioning of marine ecosystems.The number of ships with installed scrubber systems is increasing, but legislation on scrubber discharge is lagging, inconsistent between countries, and often insufficient to protect the environment. ICES recommends the use of cleaner low-sulphur fuels, such as marine gas oil, to eliminate scrubber use and associated impacts on the marine environment.Until this is possible, ICES proposes a set of measures to mitigate scrubber impacts.
-
ICES VIEWPOINT: Scrubber discharge water from ships – risks to the marine environment and recom-mendations to reduce impacts
- New global standards on sulphur content in marine fuels have led to an increasing number of ships installing exhaust gas cleaning systems, also known as scrubbers, to reduce air emissions of sulphur oxides. Ships equipped with a scrubber can continue to use heavy fuel oil, resulting in significant discharge of acidified water containing several contaminants, such as heavy metals, persistent organic pollutants (POPs; mainly polycyclic aromatic hydrocarbons), and nitrogen compounds.The simplest and most common type of scrubber system, the open-loop scrubber, directly discharges the contaminated water in to the sea. The use of scrubber systems by ships is an emerging global problem and an additional pressure on the marine environment. The substances found in scrubber discharge water can cause acute effects on marine biota and may have further impacts, through bioaccumulation, acidification, and eutrophication, on the structure and functioning of marine ecosystems.The number of ships with installed scrubber systems is increasing, but legislation on scrubber discharge is lagging, inconsistent between countries, and often insufficient to protect the environment. ICES recommends the use of cleaner low-sulphur fuels, such as marine gas oil, to eliminate scrubber use and associated impacts on the marine environment.Until this is possible, ICES proposes a set of measures to mitigate scrubber impacts
-
X-ploring new tools for paleontologists: the RBINS-RMCA micro-CT lab at your service!
- X-ray computed tomography (CT-) scanning is revolutionizing the study of extinct organisms. Its non-invasive and non-destructive character makes it currently by far the most potent method to allow fossils to be studied in three dimensions and with unprecedented detail. More importantly, and differing from other 3D techniques, CT-scanning looks through and inside objects, revealing hidden structures and characters. Recent innovations in the field of CT-scanning allow obtaining details up to a few micrometers in resolution, and higher quality images of relatively dense materials, like fossils, even when wholly encased in hard sediment (Keklikoglou et al., 2019). In 2016, the Royal Belgian Institute of Natural Sciences (RBINS) acquired two high-end X-ray CT machines: the micro-CT RX EasyTom and the nano-CT XRE-Tescan UniTom. Both scanners are currently nearly full time in use to help accomplishing the gigantic task of the digitization of the RBINS and Royal Museum for Central Africa (RMCA) type collections, the aim of two multi-year Belspo funded projects, DiSSCo-Fed (2018-2023) and DIGIT-4 (2019-2024). With about 300.000 types and 48.000.000 general specimens, 46.000 and 3.000.000 respectively in their paleontology collections, the results of nearly two centuries of intensive collecting and research, these two Belgian Federal Scientific Institutions (FSI’s) are major players in the European framework of scientific research infrastructures for natural history. Digitizing this large number of types, spread across almost the entire Tree of Life, and exhibiting an entire array of differing taphonomies, results in a steadily growing expertise of the RBINS-RMCA micro-CT lab (Brecko et al., 2018). While the newly acquired infrastructure and ongoing digitization projects are primarily oriented towards the digitization of type and figured specimens, these also offer great opportunities for researchers and teachers in various disciplines of paleontology. Targeting on researchers interested in incorporating micro-CT as a technique in their research projects, the current digitization workflow of the RBINS-RMCA micro-CT lab will be presented. While micro-CT offers many advantages, there are also pitfalls and limitations that need to be considered. Based on our expertise, and illustrated by some of our scanning results, important constraints that may block the pathway between your expectations and perfect micro-CT-imaging results that can be fully incorporated into research projects will be presented. Possible effects of some of the most important parameters that may influence the quality of the output, and thus can increase the signal to noise ratio (SNR) will be reviewed, such as the size and shape of the specimen to be scanned, the density of its matrix the specimen is made of or encased in, the presence of certain minerals (e.g. pyrite) and how these may be distributed inside the specimen (e.g. finely disseminated, dense masses or crystals), the best possible resolution in relation to the specimen and preferred output, the time needed to scan a specimen, the choice between machines to be used and their limits and different possible scan settings (e.g. beam power, filters…). Post-processing parameters to be considered are the size of the image stack output (will the computer be able to handle the amount of Gigabytes?), the time needed to render and segment regions of interest and optimize 3D-models, and which format suits best to visualize and export the data (renderings, meshes, videos, virtual sections…). While segmentation may be a time-consuming task, new developments like the incorporation of artificial intelligence (e.g. the Deep Learning function in Dragonfly ORS) offer great potential to reduce the workload in complex segmentation. Many researchers are also teachers. The reason why they may also be particularly interested in the 3D models of the already digitized types that are available on the Virtual Collections platforms of the RBINS (http://virtualcollections.naturalsciences.be/) and RMCA (https://virtualcol.africamuseum.be/). While 3D models are not intended to replace physical specimens, they may become significant teaching aids in both the physical and virtual classroom. In addition, the presence of a steadily growing number of 3D-models and animations of extant animals that are also added to these Virtual Collections, would allow teachers to connect fossils (in general incomplete) with extant (more complete) relatives. Last but not least, while the focus of this communication is largely on micro-CT, some of the many other new techniques that are being tested, used and improved will be highlighted (see e.g. Brecko & Mathys, 2020; Brecko et al., 2014, 2016, 2018; Mathys et al., 2013, 2019 for some examples). Interested in our work, expertise, techniques, equipment, or scans-on-demand? Please do not hesitate to reach out! References Brecko, J., Lefevre, U., Locatelli, C., Van de Gehuchte, E., Van Noten, K., Mathys, A., De Ceukelaire, M., Dekoninck, W., Folie, A., Pauwels, O., Samyn, Y., Meirte, D., Vandenspiegel, D. & Semal, P. 2018. Rediscovering the museum’s treasures: μCT digitisation of the type collection. Poster presented at 6th annual Tomography for Scientific Advancement (ToScA) symposium, Warwick, England, 10-12 Sept 2018. Brecko, J. & Mathys, A., 2020. Handbook of best practice and standards for 2D+ and 3D imaging of natural history collections. European Journal of Taxonomy, 623, 1-115. Brecko, J., Mathys, A., Dekoninck, W., De Ceukelaire, M., VandenSpiegel, D. & Semal, P., 2016. Revealing Invisible Beauty, Ultra Detailed: The Influence of Low-Cost UV Exposure on Natural History Specimens in 2D+ Digitization. PLoS One 11(8):e0161572. Brecko, J., Mathys, A., Dekoninck, W., Leponce, M., Vanden Spiegel, D. & Semal, P., 2014. Focus stacking: Comparing commercial top-end set-ups with a semi-automatic low budget approach. A possible solution for mass digitization of type specimens. Zookeys, 464, 1-23. Keklikoglou, K., Faulwetter, S., Chatzinikolaou, E., Wils, P., Brecko, J., Kvaček, J., Metscher, B. & Arvanitidis, C. 2019. Micro-computed tomography for natural history specimens: a handbook of best practice protocols. European Journal of Taxonomy, 522, 1-55. Mathys, A., Semal, P., Brecko, J. & Van den Spiegel, D., 2019. Improving 3D photogrammetry models through spectral imaging: Tooth enamel as a case study. PLoS One, 14(8): e0220949. Mathys, A., Brecko, J., Di Modica, K., Abrams, G., Bonjean, D. & Semal, P., 2013. Agora 3D. Low cost 3D imaging: a first look for field archaeology. Notae Praehistoricae, 33/2013, 33-42.
-
Organic matter processing in a [simulated] offshore wind farm ecosystem in current and future climate and aquaculture scenarios
- The rapid development of blue economy and human use of offshore space triggered the concept of co-location of ma- rine activities and is causing diverse local pressures on the environment. These pressures add to, and interact with, global challenges such as ocean acidification and warming. This study investigates the combined pressures of climate change and the planned co-location of offshore wind farm (OWF) and aquaculture zones on the carbon flow through epifaunal communities inhabiting wind turbines in the North Sea. A 13 C-labelled phytoplankton pulse-chase experi- ment was performed in mesocosms (4 m 3 ) holding undisturbed hard-substrate (HS) communities, natural sediment with infauna, and mobile invertebrate predators. Carbon assimilation was quantified under current and predicted future-climate conditions (+3 °C and −0.3 pH units), as well as a future-climate co-use scenario with blue mussel (Mytilus edulis) aquaculture. Climate change induced an increase in macrofaunal carbon assimilation as well as an organic enrichment of underlying sediments. Dynamic (non-)trophic links between M. edulis and other HS epifauna resulted in shifts among the species contributing most to the phytoplankton-derived carbon flow across climate scenar- ios. Increased inter- and intraspecific resource competition in the presence of M. edulis aquaculture prevented a large increase in the total assimilation of phytoplankton by HS fauna. Lower individual carbon assimilation rates by both mussels and other epifauna suggest that if filter capacity by HS epifauna would approach renewal by advection/ mixing, M. edulis individuals would likely grow to a smaller-than-desired commercial size. In the same scenario, ben- thic organic carbon mineralisation was significantly boosted due to increased organic matter deposition by the aqua- culture set-up. Combining these results with in situ OWF abundance data confirmed M. edulis as the most impactful OWF AHS species in terms of (total) carbon assimilation as well as the described stress responses due to climate change and the addition of bivalve aquaculture.
-
The discovery of a Balaenomorpha (Persufflatius renefraaijeni n. gen., n. sp.) from the upper Miocene of the Netherlands sheds new light on the cranial anatomy of archaic rorqual relatives
-
Ieper - De Meersen. Deel 1. Een kerk, kerkhof en abdij in de Ieperse binnenstad. Studie van de begravingen
-
Fysisch antropologisch onderzoek van 500 skeletten
-
Taxonomic and phylogenetic study of the late Oligocene heterodont odontocete Eosqualodon langewieschei provides clues about the emergence of modern toothed whales
-
Revision of the lanternfly genus Limois Stål, 1863 (Hemiptera: Fulgoromorpha: Fulgoridae) with description of a new species from China
-
Atlas Natuursteen in Limburgse gebouwen: een frisse kijk op geologie, beschrijving, herkomst en gebruik
