A5030613963- Paleontology and Evolutionary Biology
- Evolution and Paleontology Studies
- Ichthyology and Marine Biology
- Advanced X-ray Imaging Techniques
- dental development and anomalies
- Paleontology and Stratigraphy of Fossils
- Developmental Biology and Gene Regulation
- Amphibian and Reptile Biology
- Geological Studies and Exploration
- Fish Biology and Ecology Studies
- Optical measurement and interference techniques
- Morphological variations and asymmetry
- Traumatic Brain Injury and Neurovascular Disturbances
- Cerebrovascular and Carotid Artery Diseases
- Cellular Mechanics and Interactions
- Geological and Geochemical Analysis
- Cephalopods and Marine Biology
- Pleistocene-Era Hominins and Archaeology
- Turtle Biology and Conservation
- Advanced MRI Techniques and Applications
- Bone Metabolism and Diseases
- Oral and Maxillofacial Pathology
- Hydrocarbon exploration and reservoir analysis
- Zebrafish Biomedical Research Applications
- Craniofacial Disorders and Treatments
European Synchrotron Radiation Facility
2015-2024
Uppsala University
2015-2024
University of Wisconsin–Madison
2023-2024
Université Nantes Angers Le Mans
2024
Laboratoire de Planétologie et Géosciences
2021-2024
Centre National de la Recherche Scientifique
2004-2024
Sorbonne Université
2004-2024
Nantes Université
2024
Le Mans Université
2024
Universidad de La Frontera
2023
Abstract The recent developments of phase-contrast synchrotron imaging techniques have been great interest for paleontologists, providing three-dimensional (3D) tomographic images anatomical structures, thereby leading to new paleobiological insights and the discovery species. However, until now, it has not used on features smaller than 5–7 μm voxel size in fossil bones. Because much information is contained within 3D histological architecture bone, including an ontogenetic record, crucial...
The Cretaceous-Palaeogene mass extinction around 66 million years ago was triggered by the Chicxulub asteroid impact on present-day Yucatán Peninsula1,2. This event caused highly selective that eliminated about 76% of species3,4, including all non-avian dinosaurs, pterosaurs, ammonites, rudists and most marine reptiles. timing its aftermath have been studied mainly millennial timescales, leaving season unconstrained. Here, studying fishes died day Mesozoic era ended, we demonstrate took...
Significance Some lineages of organisms have undergone major evolutionary radiations, while others not. Establishing why is a central goal research. Whole-genome duplication (WGD) often proposed as having caused the spectacular radiation teleost fishes. However, due to absence genetic data for fossil species, it has been impossible pinpoint precisely when WGD occurred during history. We use three-dimensional measurements fossilized bone cell spaces estimate genome sizes in extinct observing...
Abstract Here we study the occurrence of torsion‐resisting morphological and histological features (thin bone walls, circular shaft cross‐section, oblique collagen fibers, laminar tissue arrangement) in a sample 168 long bones from wings legs 22 bird species. These structural parameters were measured mid diaphyseal undemineralized cross‐sections analyzed using uni‐, bi‐, multivariate (principal components analysis) data analysis techniques. We found that four variables are significantly...
Firm attachments binding muscles to skeleton are crucial mechanical components of the vertebrate body. These (entheses) complex three-dimensional structures, containing distinctive arrangements cells and fibre systems embedded in bone, which can be modified during ontogeny. Until recently it has only been possible obtain 2D surface thin section images entheses, leaving their 3D histology largely unstudied except by extrapolation from data. Entheses frequently preserved fossil bones, but...
The transition from jawless to jawed vertebrates (gnathostomes) resulted in the reconfiguration of muscles and skeleton head, including creation a separate shoulder girdle with distinct neck muscles. We describe here only known examples preserved musculature placoderms (extinct armored fishes), phylogenetically most basal vertebrates. Placoderms possess regionalized muscular anatomy that differs radically extant sharks, which is often viewed as primitive for gnathostomes. placoderm data...
Evolutionary stasis (long-term stability of morphology in an evolving lineage) is a pattern for which explanations are usually elusive. The Triassic tetrapod Gerrothorax pulcherrimus, gill-bearing temnospondyl, survived 35 million years the Germanic Basin Central Europe persisting throughout dinosaur-dominated Late period. This evolutionary coincides with occurrence this species wide range habitats and environmental conditions. By combination palaeoecological palaeohistological analyses, we...
Archaeopteryx is an iconic fossil taxon with feathered wings from the Late Jurassic of Germany that occupies a crucial position for understanding early evolution avian flight. After over 150 years study, its mosaic anatomy unifying characters both non-flying dinosaurs and flying birds has remained challenging to interpret in locomotory context. Here, we compare new data three specimens obtained through phase-contrast synchrotron microtomography representative sample archosaurs employing...
Growth plate and articular cartilage constitute a single anatomical entity early in development but later separate into two distinct structures by the secondary ossification center (SOC). The reason for such separation remains unknown. We found that evolutionarily SOC appears animals conquering land - amniotes. Analysis of pattern mammals with specialized extremities (whales, bats, jerboa) revealed correlates extent mechanical loads. Mathematical modeling reduces stress within growth plate....
The origin and early diversification of jawed vertebrates involved major changes to skeletal soft anatomy. Skeletal transformations can be examined directly by studying fossil stem gnathostomes; however, preservation anatomy is rare. We describe the only known example a three-dimensionally mineralized heart, thick-walled stomach, bilobed liver from arthrodire placoderms, gnathostomes Late Devonian Gogo Formation in Western Australia. application synchrotron neutron microtomography this...
Cerebrovascular and neurological diseases exhibit sex-specific patterns in prevalence, severity, regional specificity, some of which are associated with altered cerebral blood flow (CBF). Females often higher resting CBF, but understanding the impact sex per se on CBF is hampered by study variability age, comorbidities, medications, control for menstrual cycle or hormone therapies. A majority studies report whole brain without differentiating between grey white matter, assessing CBF. Thus,...
Abstract The locomotion of early tetrapods has long been a subject great interest in the evolutionary history vertebrates. However, we still do not have precise understanding radiation their locomotory strategies. We present here first palaeohistological study based on theoretical biomechanical considerations among highly diversified group tetrapods, temnospondyls. Based quantification microanatomical and histological parameters humerus femur nine genera, this multivariate analysis provides...
SUMMARY Apateon , a key genus among Branchiosauridae from the Carboniferous—Permian of Europe, is often considered closely related to salamanders on basis developmental similarities, anatomical features, and life history. The current work deals with recognition heterochronies three “time‐averaged populations” based inference histological features already studied in extant urodeles. Our study performed long bones 22 specimens pedestris caducus . Histological observations show that diaphyseal...
Because of its close relationship to tetrapods, Eusthenopteron is an important taxon for understanding the establishment tetrapod body plan. Notably, it one earliest sarcopterygians in which humerus pectoral fin skeleton preserved. The microanatomical and histological organization this provides data evolutionary steps that built up distinctive architecture limb bones. Previous studies showed Eusthenopteron's long-bone was established through typical ossification modalities. Based on a...
The amniotes generally lay eggs on land and are thereby differentiated from lissamphibians (salamanders, frogs caecilians) by their developmental pattern. Although a number of 330–300-Myr old fossils regarded as early tetrapods placed close to the basis anatomical data, we still do not know whether pattern was more similar those or amniotes. Here report palaeohistological skeletochronological evidence supporting salamander-like development in seymouriamorph Discosauriscus . Its long-bone...
Growth and patterning of craniofacial sutures is subjected to the effects mechanical stress. Mechanotransduction processes occurring at margins are not precisely understood. Here, we propose a simple theoretical model based on orientation collagen fibres within suture in response local We demonstrate that fibre alignment generates an instability leading emergence interdigitations. confirm appearance this both analytically numerically. To support our model, use histology synchrotron X-ray...
Abstract Fossils of juvenile Mesozoic birds provide insight into the early evolution avian development, however such fossils are rare. The analysis ossification sequence in these early-branching has potential to address important questions about their comparative developmental biology and help understand morphological ecological differentiation. Here we report on an enantiornithine specimen from Early Cretaceous Europe, which sheds new light osteogenesis this most species-rich clade birds....
Detailed histological analyses are desirable for zebrafish mutants that models human skeletal diseases, but traditional techniques limited to two-dimensional thin sections with orientations highly dependent on careful sample preparation. On the other hand, provide three-dimensional (3D) datasets including µCT scanning typically visualizing bony skeleton and lack resolution. We combined diffusible iodine-based contrast enhancement (DICE) propagation phase-contrast synchrotron radiation...
The debate about the origin of vertebrate dentition has been given fresh fuel by new fossil discoveries and developmental studies extant animals. Odontodes (teeth or tooth-like structures) can be found in two distinct regions, 'internal' oropharyngeal cavity 'external' skin. A recent hypothesis argues that regularly patterned odontodes is a specific feature, whereas external skeleton lack this organization. However, argument relies on skeletal system modern chondrichthyans (sharks their...
ABSTRACT We used propagation phase contrast X‐ray synchrotron microtomography to study the three‐dimensional (3D) histology of scales two osteostracans, Tremataspis and Oeselaspis , members a jawless vertebrate group often cited as sister jawed vertebrates. 3D‐models canal systems other internal structures are assembled based on virtual thin section datasets compared with previous models real sections. The primary homology framework in taxa is revised new histological details revealed...
Placoderms are considered as the first jawed vertebrates and constitute a paraphyletic group in stem-gnathostome grade. The acanthothoracid placoderms among phylogenetically most basal morphologically primitive gnathostomes, but their neurocranial anatomy is poorly understood. Here we present near-complete three-dimensional skull of Romundina stellina, small Early Devonian from Canadian Arctic Archipelago, scanned with propagation phase contrast microtomography at 7.46 μm isotropic voxel...