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Verschillen tussen "museumgeologen" en "vrije geologen" - Différences entre les "géologues de musée" et les "géologues libres"
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RBINS Staff Publications 2022
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Vertebral morphology and intracolumnar variation of the iconic African viperid snake Atheris (Serpentes, Viperidae)
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We here provide a detailed description of the vertebral morphology of the African arboreal viperid snakes of the genus Atheris. Vertebrae of three different species of the genus, i.e., Atheris desaixi, Atheris hispida, and Atheris katangensis, were investigated via the aid of μCT (micro‐computed tomography) scanning. We describe several vertebrae from different regions of the vertebral column for all three species, starting from the atlas‐axis complex to the caudal tip, in order to demonstrate important differences regarding the intracolumnar variation. Comparison of these three species shows an overall similar general morphology of the trunk vertebrae among the Atheris species. We extensively compare Atheris with other known viperids. As the sole arboreal genus of Viperinae the prehensile nature of the tail of Atheris is reflected in its caudal vertebral morphology, which is characterized by a high number of caudal vertebrae but also robust and anteroventrally oriented pleurapophyses as a skeletal adaptation, linked with the myology of the tail, to an arboreal lifestyle. We anticipate that the extensive figuring of these viperid specimens will also aid identifications in paleontology.
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RBINS Staff Publications 2024
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Vertebrate predation in the Late Devonian evidenced by bite traces and regurgitations: implications for an early tetrapod freshwater ecosystem
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The terrestrialization process by vertebrates occurred during the Devonian period, with fully land-dwelling tetrapods recorded in the Carboniferous. Thus, the Late Devonian is an important period for deciphering the ecological pressures that applied during the water-to-land transition. Higher predation pressures in the underwater environment have been suggested as an influential biotic evolutionary factor in this key habitat shift. Direct evidence of ancient predation on Palaeozoic vertebrates is seen in the form of rare traces preserved on fossils, and these range from trauma observed on the skeleton (such as attack marks) to ingested food remains (bromalites). The late Famennian freshwater ecosystem of Strud (Belgium) consists of a rich assemblage of many coeval gnathostomes or jawed fishes (placoderms, ‘acanthodians’, actinopterygians, and various sarcopterygian groups including tetrapods). Here we analyse the record of direct evidence for predation in the Strud vertebrate fossil assemblage. We recognize 12 regurgitalites and 13 bite traces, including a rare case of a tooth embedded in its original prey body target. Fossils from regurgitalites were imaged using scanning electron microscopy and chemically analysed to test for their possible ingestion signature by comparison with other isolated skeletal remains from the same locality. From this evidence, tristichopterid tetrapodomorphs are inferred to be the highest consumers of the trophic network, targeting small placoderms, and porolepiforms, and probably congeners. We observe two possible prey patterns in regurgitalites, for sarcopterygians and actinopterygians, both of which are associated with acanthodians. In Strud, no trophic position can be deduced for tetrapods from direct fossil evidence of predation.
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RBINS Staff Publications 2022
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Vertebrate predation in the Late Devonian evidenced by bite traces and regurgitations: implications for an early tetrapod freshwater ecosystem.
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The terrestrialization process by vertebrates occurred during the Devonian period, with fully land-dwelling tetrapods recorded in the Carboniferous. Thus, the Late Devonian is an important period for deciphering the ecological pressures that applied during the water-to-land transition. Higher predation pressures in the underwater environment have been suggested as an influential biotic evolutionary factor in this key habitat shift. Direct evidence of ancient predation on Palaeozoic vertebrates is seen in the form of rare traces preserved on fossils, and these range from trauma observed on the skeleton (such as attack marks) to ingested food remains (bromalites). The late Famennian freshwater ecosystem of Strud (Belgium) consists of a rich assemblage of many coeval gnathostomes or jawed fishes (placoderms, ‘acanthodians’, actinopterygians, and various sarcopterygian groups including tetrapods). Here we analyse the record of direct evidence for predation in the Strud vertebrate fossil assemblage. We recognize 12 regurgitalites and 13 bite traces, including a rare case of a tooth embedded in its original prey body target. Fossils from regurgitalites were imaged using scanning electron microscopy and chemically analysed to test for their possible ingestion signature by comparison with other isolated skeletal remains from the same locality. From this evidence, tristichopterid tetrapodomorphs are inferred to be the highest consumers of the trophic network, targeting small placoderms, and porolepiforms, and probably congeners. We observe two possible prey patterns in regurgitalites, for sarcopterygians and actinopterygians, both of which are associated with acanthodians. In Strud, no trophic position can be deduced for tetrapods from direct fossil evidence of predation.
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RBINS Staff Publications 2022
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Vertical and lateral distribution of Foraminifera and Ostracoda in the East Frisian Wadden Sea – developing a transfer func-tion for relative sea-level change.
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RBINS Staff Publications 2019
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Vertical distribution of termites in a Panamanian rainforest
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RBINS Staff Publications
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Vertical dynamics of suspended particulate matter and chlorophyll-a in a well-mixed coastal turbid system
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RBINS Staff Publications 2025 OA
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Vertical stratification of termites in a Panamanian rainforest
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RBINS Staff Publications
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Vertical stratification of the termite assemblage in a neotropical rainforest
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RBINS Staff Publications
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Vertical transmission of Cardinium bacteria in parthenogenetic non-marine ostracods (Crustacea)
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Bacterial endosymbionts are common in terrestrial arthropods, where they can manipulate host biology and reproduction, with Wolbachia and Cardinium as the best-known examples. Vertical transmission is a hallmark of such endosymbiosis. The high incidence of parthenogenesis makes non-marine ostracods (small, bivalved crustaceans) excellent models for exploring the potential effects of endosymbiosis on host reproduction in fully aquatic arthropods. Here, we complement DNA sequencing-based detection of Cardinium in non-marine ostracods with an imaging approach based on microdissection and fluorescence in situ hybridization (FISH). We use confocal microscopy to illustrate the location and spatial organization of Cardinium cells within female ovaries and eggs in natural, parthenogenetic populations of three species of ostracods with mixed reproduction. Our results provide evidence that these bacteria are stable endosymbionts and confirm vertical transmission of Cardinium in non-marine ostracods. The location of Cardinium in reproductive tissues of parthenogenetic females further indicates that these intracellular bacteria are potential reproductive manipulators in at least some non-marine ostracod species. Given that our knowledge on endosymbionts is still largely biased towards terrestrial arthropods with haplodiploidy, our results open the way to novel comparative studies of reproductive manipulation by endosymbionts in a much wider range of taxa.
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RBINS Staff Publications 2025
