Search results

This contribution reports on six holothuroids that have recently been collected on the Mediterranean continental slope. One species, Pseudothyone serrifera (Oestergren, 1898) (Holothuroidea, Dendrochirotida), is a new record for the Mediterranean Sea (Capraia Island, Italy). This uncommon species was hitherto only known from the North Atlantic (Scandinavia, the Faroe Islands and the Bay of Biscay). We provide a re-description of P. serrifera.

This contribution provides an overview of the scientific career of the late Dr Claude Massin (1948–2021), listing his scientific activities (academic career, participation to and organization of expeditions and scientific conferences, publications) as well as the taxa he described as new to science and the eponyms that were dedicated to him. The scientific career of Claude Massin is briefly sketched against the background of the personal family-life.

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.

Multituberculates are an extinct rodent-like order that lived between Late Jurassic and late Eocene, on almost every continent. Due to their extraordinary longevity, their evolutive history is important to understand. One of the most numerous and best-preserved groups is the superfamily Djadochtatherioidea from the Late Cretaceous of the Gobi Desert. All djadochtatherioid genera are monospecific, except Kryptobaatar. The large number of K. dashzevegi fossils come from Outer Mongolia, while the only two specimens found in Bayan Mandahu, Inner Mongolia, China belong to K. mandahuensis. However, a new particularly well-preserved specimen (IMM 99BM-IV/5) found in Bayan Mandahu during the 1990s Sino-Belgian expeditions seems at first sight very close to K. dashzevegi. IMM 99BM-IV/5 consists of a skull associated with cervical and thoracic vertebrae, ribs, shoulder girdle, broken right humerus and an almost complete left forelimb. It is the first specimen for which the hand is described in detail. Based on micro-CT scan and comparison, it appears that IMM 99BM-IV/5 presents morphological characters of both species of Kryptobaatar, as well as new characters of its own. Phylogenetic analysis suggests that IMM 99BM-IV/5 has an intermediate position between K. dashzevegi and K. mandahuensis and could therefore belong to a new species. However, Kryptobaatar is paraphyletic in the resulting tree, which raises again questions about intraspecific variability in multituberculates. Since only 13 specimens of Kryptobaatar out of the hundreds found have been studied, it is impossible to reliably know if IMM 99BM-IV/5 is included in the variability of K. dashzevegi or not. However, it is crucial to know this variability to define whether the genus is monospecific or not. By comparing K. mandahuensis with published specimens, we concluded that it is a valid species. This work also highlighted the lack of knowledge of the variability of the type species K. dashzevegi, without which it is impossible to clearly assign IMM 99BM-IV/5. Finally, endemism alone is not the cause of this variability, but the role of paleoenvironment or age is currently unknown.

The Crocodylia include all modern crocodiles, alligators, caimans and gharials, and their extinct relatives. They are an ancient lineage that originated around 70 million years ago. Recently, the field of crocodylian paleontology has experienced a rise in attention from researchers, however, much is still unknown about the early evolution of this group. Our research describes newly discovered fossil material comprised of a small crocodylian skull and associated partial lower jaw of early Paleocene age. It was discovered during a Belgian-Chinese expedition in Qianshan Basin, Anhui Province, China, as part of a bilateral cooperation project between the Royal Belgian Institute of Natural Sciences and the Institute of Botany of the Chinese Academy of Sciences. In the present study, the fossil material is formally described for the first time. Micro-CT scans are made to visualize internal anatomical structures, as well as characters hidden by the sediment. A comprehensive morphological study is executed, revealing that the specimen is a juvenile. It likely constitutes a new species and genus, as it differs from other crocodyloids by several autapomorphies. A phylogenetic analysis based on morphological characteristics reveal that this specimen is the most basal taxon among Crocodyloidea, a group that comprises all species more closely related to modern crocodiles than to modern alligators, caimans, or gharials. Although it is not the oldest crocodyloid ever reported, it is the earliest crocodyloid in Asia. Moreover, its basal phylogenetic position implies that it is part of an ancient ghost lineage of crocodyloids that had already been around in Asia for a longer time. The presence of crocodyloid remains in the Late Cretaceous of North America and the late Paleocene of Europe suggests that crocodyloids may have migrated there from Asia early on in their evolutionary history.

La compréhension progressive des différents réchauffements climatiques intenses du Paléogène inférieur (PETM, ETM-2, EECO…) a créé un intérêt évident pour une stratigraphie de plus en plus fine des bassins sédimentaires qui ont enregistrés ces événements. Ces derniers, identifiés sur base géochimique, demandent à être corrélés avec les événements biologiques qui en découlent et qui ont été, eux aussi, enregistrés dans ces bassins. Dans ce cadre, les bassins parisien, de Londres et de Belgique, formant le sud du Bassin de la Mer du Nord, représentent des modèles de choix pour la communauté géoscientifique de par leur reconnaissance historique et les étages internationaux Lutétien, Yprésien et Thanétien qu’ils ont respectivement permis de définir. Si les connaissances sur les dépôts marins ont fait d’énormes progrès notamment grâce aux études micropaléontologiques détaillées, qu’en est-il aujourd’hui des dépôts continentaux souvent délaissés par leur complexité à être interprétés? Vingt-cinq ans d’expertise en biochronologie mammalienne de notre équipe bruxelloise et de ses collaborateurs sont ici survolés, mettant en exergue l’utilité des mammifères en stratigraphie et paléogéographie. L’exposé porte tant sur des taxons marqueurs que des faunes entières issues de sites historiques ou nouveaux du Bassin parisien et de son complémentaire le bassin belge (Hainin, Maret, Rivecourt, Dormaal, Erquelinnes, Meudon, Sotteville-sur-Mer, Egem, Oosterzele…). Ainsi, des niveaux de référence de l’échelle biochronologique européenne des mammifères du Paléogène (MP) sont précisés, de nouveaux âges à mammifères européens sont identifiés et la stratigraphie tant à l’échelle locale que nord-ouest européenne est affinée. Malgré tout le travail accompli, les questions sont nombreuses et beaucoup reste à faire tant l’étude des faunes de mammifères est incomplète!

The paleobotanist Philippe Gerrienne was internationally renowned for his work on early land plants. His research career was however not limited to the study of Devonian floras. He also actively contributed to the progress of Belgian Wealdian (Early Cretaceous), early Paleogene and Quaternary research. In this framework, Philippe’s interest for Paleogene plants already appeared when he helped to sort Stockmans’ paleobotanical collections of the Royal Belgian institute of Natural Sciences (RBINS) during a civil service he did between 1987 and 1989. In the old conservatoires, he discovered hundreds of silicified trunks and branches from the “upper Landenian” (early Eocene) of Belgium, which were collected in 1970 in the area of Hoegaarden during the construction of the Brussels-Liège highway (E40-A3). From 1994, the RBINS developed new research activities in early Paleogene Belgian sites. At this occasion, fossil plants discovered next to vertebrates from the warm earliest Eocene at Dormaal were studied in collaboration with the Royal Museum for Central Africa, which owns an excellent xylotheque of tropical woods (Doutrelepont et al., 1997). This first step allowed in 1999, after several preliminary works, to start a partnership with the University of Liège (ULiège) and the University of Mons (UMons) through a F.R.F.C.-I.C. (FNRS) project, leaded by Muriel Fairon-Demaret (ULg), on the "Reconstruction of the terrestrial ecosystems in Belgium during the Palaeocene-Eocene transition, 50-60 million years ago". During three years (1999-2002), numerous fieldworks in Belgium and research activities in labs were realized, including a first database of more than 600 hundreds fossil wood specimens. In this overview, I summarize the main accomplishments that have been done in the field. At Péruwelz, we found a silicified trunk fragment of a new arborescent Ericaceae in the marine Thanetian (Upper Paleocene), which was named Agaristoxylon garennicum (Gerrienne et al., 1999). The paleoenvironment of Dormaal was reconstructed based on fruits and seeds from the Paleocene Eocene Thermal Maximum (Fairon-Demaret & Smith, 2002). The most successful work was probably the study of the in situ monospecific Glyptostroboxylon forest of Overlaar at Hoegaarden (Fairon-Demaret et al., 2003). This warm Everglades-like paleoenvironment attracted the Belgian media and finally led to the construction of the geopark of Hoegaarden. In 2004, Philippe described the Givetian (middle Devonian) seed precursor Runcaria heinzelinii Stockmans, 1968 from Ronquières, Belgium (Gerrienne et al., 2004). The rediscovery of the 385-million-year-old basal seed plant and, the same year, the retirement of his close colleague Muriel Fairon-Demaret focused definitively his interest on the Paleozoic. References Doutrelepont, H., Smith, T., Damblon, F., Smith, R. & Beeckman, H., 1997. Un bois silicifié de peuplier de la transition Paléocène-Eocène de Dormaal, Belgique. Bulletin de l'Institut royal des Sciences naturelles de Belgique, 67, 183-188. Fairon-Demaret, M. & Smith, T., 2002. Fruits and seeds from the Tienen Formation at Dormaal, Paleocene-Eocene transition in eastern Belgium. Review of Palaeobotany and Palynology, 122, 47-62. Fairon-Demaret, M., Steurbaut, E., Damblon, F., Dupuis, C., Smith, T. & Gerrienne, P., 2003. The in situ Glyptostroboxylon forest of Hoegaarden (Belgium) at the Initial Eocene Thermal Maximum (55 Ma). Review of Palaeobotany and Palynology, 126, 103-129. Gerrienne, P., Beeckman, H., Damblon, F., Doutrelepont, H., Fairon-Demaret, M. & Smith, T., 1999. Agaristoxylon garennicum Gerrienne et al., gen. et sp. nov., an arborescent Ericaceae from the Belgian Upper Paleocene: palaeoenvironmental implications. Review of Palaeobotany and Palynology, 104, 299-307. Gerrienne, P., Meyer-Berthaud, B., Fairon-Demaret, M., Streel, M. & Steemans, P., 2004. Runcaria, a Middle Devonian Seed Plant Precursor. Science, 306, 856-858.

Avec plus d’un an de retard suite à la crise COVID (Anthropocène supérieur), nous présentons ici un squelette partiel d’un hibou fossile de grande taille qui entretemps a déjà été publié (Mayr et al., 2020). Ce retard n’est toutefois pas réellement préjudiciable étant donné que le spécimen a été découvert il y a déjà plus de 30 ans dans les couches du Wasatchien moyen (Wa-3) de la Formation de Willwood à McCullough Peaks, au Wyoming (USA), permettant ainsi de le dater entre 54,5 et 55,0 Ma (début de l’Eocène inférieur). Le spécimen inclut la majorité des os postcraniens d’un des strigiformes fossiles les plus complets du Paléogène. Primoptynx poliotaurus mesurait environ 50 centimètres de long, taille comparable à Hedwig, le harfang des neiges de Harry Potter, et appartient à un groupe de hiboux proche de la famille éteinte des Protostrigidae, bien que ne partageant pas avec ces derniers la morphologie dérivée du tibiotarse. Les pattes de Primoptynx sont différentes de celles des strigidés actuels (hiboux et chouettes). Les hiboux ont aujourd'hui quatre doigts avec des griffes de même taille pour attraper des proies relativement petites, et les tuer avec le bec. Primoptynx a les premier et second doigts plus longs, comme on le voit chez les éperviers, buses, aigles et autres membres de la famille des Accipitridae. Ces deux doigts plus développés sont utilisés pour épingler les proies, qui sont dès lors percées par les serres. Primoptynx était donc un hibou qui chassait comme un aigle, des mammifères de taille moyenne. Ce fossile montre, avec d’autres découvertes, que durant l’Eocène inférieur il y avait déjà une certaine diversité de strigiformes, de différentes tailles, qui occupaient diverses niches écologiques. Le succès des hiboux allait de pair avec celui des mammifères, devenus très diversifiés à l’Eocène inférieur. L'extinction ultérieure de Primoptynx et d'autres proto-hiboux pourrait être due à l'émergence d'oiseaux de proie diurnes à l'Éocène supérieur. Financements Cette étude a été menée dans le cadre du projet BR/121/A3/PalEurAfrica, financé par la Politique Scientifique Fédérale Belge. Références Mayr G., Gingerich P.D. & Smith T., 2020. Skeleton of a new owl from the early Eocene of North America (Aves, Strigiformes) with an accipitrid-like foot morphology. Journal of Vertebrate Paleontology, 40(2):e1769116. https://doi.org/10.1080/02724634.2020.1769116.