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The Dababiya Corehole, Upper Nile Valley, Egypt: Preliminary results.
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The Dababiya corehole was drilled in the Dababiya Quarry (Upper Nile Valley, Egypt), adjacent to the GSSP for the Paleocene/ Eocene boundary, to a total depth of 140 m and bottomed in the lower Maastrichtian Globotruncana aegyptiaca Zone of the Dakhla Shale Formation. Preliminary integrated studies on calcareous plankton (foraminifera, nannoplankton), benthic foraminifera, dinoflagellates, ammonites, geochemistry, clay mineralogy and geophysical logging indicate that: 1) The K/P boundary lies between 80.4 and 80.2 m, the Danian/Selandian boundary between ~ 41 and 43 m, the Selandian/Thanetian boundary at ~ 30 m (within the mid-part of the Tarawan Chalk) and the Paleocene/Eocene boundary at 11.75 m (base [planktonic foraminifera] Zone E1 and [calcareous nannoplankton] Zone NP9b); 2) the Dababiya Quarry Member (=Paleocene/Eocene Thermal Maximum interval) extends from 11.75 to 9.5 m, which is ~1 m less than in the adjacent GSSP outcrop.; 3) the Late Cretaceous (Maastrichtian) depositional environment was nearshore, tropical-sub tropical and nutrient rich; the latest Maastrichtian somewhat more restricted (coastal); and the early Danian cooler, low(er) salinity with increasing warmth and depth of water (i.e., more open water); 4) the Paleocene is further characterized by outer shelf (~ 200 m), warm water environments as supported by foraminifera P/B ratios > 85% (~79-28 m), whereas benthic foraminifera dominate (>70%) from ~27-12 m (Tarawan Chalk and Hanadi Member) due, perhaps, in part to increased dissolution (as observed in nearby outcrop samples over this interval); 5) during the PETM, enhanced hydrodynamic conditions are inferred to have occurred on the sea-floor with increased river discharge (in agreement with sedimentologic evidence), itself a likely cause for very high enhanced biological productivity on the epicontinental shelf of Egypt; 6) correlation of in situ measured geophysical logs of Natural Gamma Ray (GR), Single-Point Resistance (PR), Self-Potential (SP), magnetic susceptibility(MS), and Resistivity, and Short Normal (SN) and Long Normal (LN) showed correspondence to the lithologic units. The Dababiya Quarry Member, in particular, is characterized by very high Gamma Ray and Resistivity Short Normal values.
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RBINS Staff Publications
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The Dababiya Quarry section: lithostratigraphy, clay mineralogy, geochemistry and paleontology.
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RBINS Staff Publications
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The DeepMIP contribution to PMIP4: methodologies for selection, compilation and analysis of latest Paleocene and early Eocene climate proxy data, incorporating version 0.1 of the DeepMIP database.
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RBINS Staff Publications 2019
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The delusion of stripes: A century-old mystery of five-lined sun skinks (Reptilia: Scincidae: Eutropis) of Peninsular India elucidated
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We re-evaluate the taxonomic identities of five-lined skinks of the genus Eutropis (E. trivittata, E. beddomei, E. nagarjunensis, and E. bibronii) inhabiting the Indian subcontinent. Previously it has been considered that E. trivittata is distributed in the western India and E. dissimilis in the northern India (from north-eastern India up to Pakistan). Based on our analysis, we revealed that the illustration (iconotype) of the untraceable type specimen of E. trivittata depicted by Hardwicke in Gray (1834) from “Dumdum” near Kolkata, West Bengal matches the typical E. dissimilis, also described from “Bengal”. The senior synonym, E. trivittata is a morphologically unique species, which is also supported by divergence in the mitochondrial 12S and 16S regions. E. trivittata is clearly separated with divergences of 5–7% from E. beddomei, E. vertebralis and E. nagarjunensis for 16S rRNA. After placing E. dissimilis with the synonymy of E. trivittata, the taxonomic status of the western Indian ‘E. trivittata’ required to be clarified. Therefore, we resurrect Mabuia vertebralis Boulenger, 1887, a junior synonym of western Indian E. trivittata, and redescribe its holotype collected from “Belgaum”, Karnataka. Although, morphologically closest to E. beddomei, Eutropis vertebralis comb. nov. is sister to E. nagarjunensis with divergence of 4% in the same mitochondrial regions. Based on our update of the currently confirmed localities for E. vertebralis comb. nov. and E. trivittata, we conducted Species Distribution Modelling (SDM) using the Maximum Entropy algorithm to predict its distribution range, and we discuss its conservation status.
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RBINS Staff Publications 2021
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The dercetid fishes (Teleostei, Aulopiformes) from the Maastrichtian (Late Cretaceous) of Belgium and The Netherlands
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Several partial skeletons from the marine Maastrichtian deposits of Belgium and the Netherlands allow to recognize four species of Dercetidae, two of which are new: Dercetis triqueter, Ophidercetis italiensis, Cyranichthys jagti sp. nov. and Apuliadercetis indeherbergei sp. nov. This newly studied material greatly enlarges the stratigraphic and paleogeographic ranges of the four concerned dercetid genera.
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RBINS Staff Publications
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The Devonian–Carboniferous boundary in Belgium and surrounding areas
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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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RBINS Staff Publications 2020
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The Diest Formation: a review of insights from the last decades
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RBINS Staff Publications 2020
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The dilemma of valuing geodiversity: geoconservation versus geotourism
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RBINS Staff Publications 2024
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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
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RBINS Staff Publications 2022
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The dispersal of domestic cats from North Africa to Europe around 2000 years ago
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The domestic cat (Felis catus) descends from the African wildcat Felis lybica lybica. Its global distribution alongside humans testifies to its successful adaptation to anthropogenic environments. Uncertainty remains regarding whether domestic cats originated in the Levant, Egypt, or elsewhere in the natural range of African wildcats. The timing and circumstances of their dispersal into Europe are also unknown. In this study, the analysis of 87 ancient and modern cat genomes suggests that domestic cats did not spread to Europe with Neolithic farmers. Conversely, they were introduced to Europe around 2000 years ago, probably from North Africa. In addition, a separate earlier introduction (first millennium before the common era) of wildcats from Northwest Africa may have been responsible for the present-day wild population in Sardinia. Tracing the origins of domestic cats (Felis catus) has been limited by a lack of ancient DNA for these animals, as well by their morphological similarity to the African wildcat (F. lybica lybica) and European wildcat (F. sylvestris). De Martino et al. generated low- to medium-coverage genomes for 87 ancient, museum, and modern cats (see the Perspective by Losos). They found that domestic cats are most genetically similar to African wildcats, although there has been widespread gene flow between wild and domestic populations. European samples that cluster with domestic cats only appear in the 1st century CE, suggesting a later dispersal of domestic cats than previously thought. Although broader sampling is needed, this study shows the complexity of population dynamics that is often revealed when looking beyond mitochondrial DNA.
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RBINS Staff Publications 2025
