Diplocynodon is an enigmatic extinct genus that is generally considered to be part of the Alligatoroidea, Crocodylia. While Alligatoroidea potentially originated in North America, Diplocynodon only has a fossil record in Europe, dating from the middle Eocene to middle Miocene (c. 45-15 Ma). The study of Diplocynodon remains curated in palaeontological collections could aid research on the morphology, phylogeny, evolution and biogeography of this large and widespread genus. We describe the Diplocynodon material in the historical Filhol collection of KU Leuven, collected at Saint-G & eacute;rand-le-Puy (early Miocene) and Ronzon (early Oligocene), from central France in the late 19th century. The aim was to identify which remains reside in the Filhol collection and to deduce the systematics behind these remains, making the collection more accessible to future research. A total of 781 skeletal elements were catalogued, including both cranial and postcranial bones. The most complete and anatomically representative specimens were photographed. Based on characteristic features, the remains from Saint-G & eacute;rand-le-Puy were confirmed as D. ratelii, a taxon that has previously been described from that locality. The remains from Ronzon could not be confidently determined in the present study.
The latest Famennian (Strunian) trilobite faunas of the Avesnois area (northern France) document the final phase of diversification of Phacopidae in shallow inner shelf environments prior to the latest Devonian-Carboniferous Hangenberg extinction preceding the Devonian-Carboniferous boundary. This study revisits historical material from the & Eacute;tr oe ungt Formation assigned to Omegops bergicus, together with a newly collected specimen from the abandoned Parcq Quarry, here described as Omegops paucilenticulatus sp. nov. The new species documents localized morphological diversification within Omegops in the Dinant Synclinorium (Belgium, France) and supports the taxonomic validity of O. bergicus. This work highlights the importance of detailed morphological characters, especially those related to eye structure and cephalic morphology. Such features are shown to be essential for reliable species-level identification among occulated phacopids of the uppermost Famennian.
In the loess stratotype of Belgium, in Romont quarry (Bassenge), minerals of a volcanic ash-fall deposit are dispersed in large quantities as a cryptotephra within a fossil humic horizon dating back to the end of the Weichselian Early Glacial. Chemical analysis of pyroxenes and amphiboles indicates that those minerals belong to the Rocourt Tephra as described in another four reference localities. The stratotype of this tephra is thus maintained in this quarry, as it is the only site of high chronostratigraphic value where it is still accessible.
The merit of the low-field magnetic susceptibility as proxy parameter is concisely reviewed. In many geological samples it is a composite consisting of a diamagnetic, paramagnetic, and ferromagnetic (sensu lato) contribution that varies with rock type. For weakly magnetic samples, the diamagnetic and paramagnetic contributions are an appreciable portion of the measured susceptibility. In such materials equating the measured susceptibility with the ferromagnetic susceptibility is not warranted. Before a susceptibility record is geologically interpreted, the underlying drivers of its variation must be understood. This is achieved by integrating susceptibility data with an extended magnetic property analysis, geochemical information, and a paleomagnetic assessment of the timing of the acquisition of the natural remanent magnetization as the magnetic minerals may post-date the sedimentation age. Measuring the susceptibility at several frequencies and in varying low applied fields provides important information on the grain-size distribution in the ultrafine grain end and, to a lesser extent, on the magnetic mineralogy. Examples discussed include research into loess/paleosol records and high-resolution time scale development. Variable surficial oxidation of magnetite particles and potential remagnetization complicate the interpretation of a susceptibility record in terms of paleoclimate.
Three tests of the holasteroid echinoid Hemipneustes striatoradiatus from the Belgian-Dutch type area of the Maastrichtian Stage preserving evidence of vertebrate-invertebrate interactions are documented and analysed. One specimen exhibits adoral pentagonal puncture marks and a large aboral scar from a mosasaur attack, with Mosasaurus hoffmannii as the presumed predator. A second test preserves evidence of two separate attacks, the first by a mosasaur, presumably Plioplatecarpus marshi, leaving both a pentagonal adoral scar and a large aboral one, and the second by a shark, leaving nonpenetrating small, deep triangular pits with tapering tails. A similar pitting is seen on the third test, arranged in clusters and here interpreted as a shark bite from above followed by a second bite subsequent to a 90 degrees rotation of the echinoid. These finds provide the first unambiguous evidence of mosasaur predation on Hemipneustes and add to the sparse record of shark-echinoid interactions, suggesting that predation on large holasteroids by vertebrates was more frequent than previously recognised. All three tests also exhibit syn vivo and postmortem invertebrate interactions, including also an undescribed serpulid.
