scholarly journals ENAMEL THICKNESS MEASUREMENTS ON 3D RECONSTRUCTIONS OF TEETH FOR PALEONTOLOGICAL APPLICATIONS

2021 ◽  
Vol XLIV-2/W1-2021 ◽  
pp. 61-65
Author(s):  
A. V. Gaboutchian ◽  
V. A. Knyaz ◽  
E. N. Maschenko ◽  
D. V. Korost ◽  
A. A. Kudaev
Keyword(s):  
Morphological Analysis ◽  
Upper Palaeolithic ◽  
Micro Computed Tomography ◽  
Enamel Thickness ◽  
Dietary Preferences ◽  
Computed Tomography Scanning ◽  
Measurement Methodology ◽  
Middle And Late Pleistocene ◽  
Thickness Measurements ◽  
Tomography Scanning

Abstract. Findings of teeth play a significant role in palaeoanthropology. And excavations in Vietnamese LangTrank cave serve as a vivid example and evidence of this statement. Teeth constitute the majority of the paleontological material dated to Middle and Late Pleistocene periods. This is to some extent the result of dietary preferences of porcupines as these rodents include in their diets bones of animals however avoiding extremely hard coronal parts of teeth. Under such circumstances teeth serve a key to taxonomic differentiation of findings as genetic analysis is often hindered by a lack of preserved DNA at such dating of material. However morphological analysis is difficult in some cases either, as teeth can be worn out or broken. In that case enamel thickness measurements become an effective study instrument as this feature varies between species. In the current study two teeth with clear signs of expressed dental wear, presumably upper fourth premolars of wild boar required more detailed analysis. Thus they were reconstructed after micro-computed tomography scanning similarly to other upper teeth picked for comparison: orang-utan tooth from the same location and two teeth from the Upper Palaeolithic Sunghir (they have been scanned earlier). This study required new approaches to image processing and measurement methodology due to marked attrition of the samples. The workflow and results of enamel thickness assessments which facilitated taxonomical differentiation of the findings are presented in the article.

scholarly journals Exposure to the RXR agonist SR11237 in early life causes disturbed skeletal morphogenesis in a rat model

2019 ◽  
Author(s):  
Holly Dupuis ◽  
Michael Andrew Pest ◽  
Ermina Hadzic ◽  
Thin Xuan Vo ◽  
Daniel B. Hardy ◽  
...  
Keyword(s):  
Growth Plate ◽  
Bone Growth ◽  
Long Bone ◽  
Tunel Staining ◽  
Long Bones ◽  
Micro Computed Tomography ◽  
Computed Tomography Scanning ◽  
Calcified Tissue ◽  
Trap Staining ◽  
Tomography Scanning

AbstractLongitudinal bone growth occurs through endochondral ossification (EO), controlled by various signaling molecules. Retinoid X Receptor (RXR) is a nuclear receptor with important roles in cell death, development, and metabolism. However, little is known about its role in EO. In this study, the agonist SR11237 was used to evaluate RXR activation on EO.Rats given SR11237 from post-natal day 5 to 15 were harvested for micro-computed tomography scanning and histology. In parallel, newborn CD1 mouse tibiae were cultured with increasing concentrations of SR11237 for histological and whole mount evaluation.RXR agonist-treated rats were smaller than controls, and developed dysmorphia of the growth plate. Cells invading the calcified and dysmorphic growth plate appeared pre-hypertrophic in size and shape corresponding with P57 immunostaining. Additionally, SOX9 positive cells were found surrounding the calcified tissue. The epiphysis of SR11237 treated bones showed increased TRAP staining, and additional TUNEL staining at the osteo-chondral junction. MicroCT revealed morphological disorganization in the long bones of treated animals. Isolated mouse long bones treated with SR11237 grew significantly less than their DMSO controls.This study demonstrates that stimulation of the RXR receptor causes irregular ossification, premature closure of the growth plate, and disrupted long bone growth in rodent models.

Ontogenetic development of the otic region in the new model organism, Leucoraja erinacea (Chondrichthyes; Rajidae)

2018 ◽  
Vol 109 (1-2) ◽  
pp. 105-114 ◽  
Author(s):  
Cathrin PFAFF ◽  
Jürgen KRIWET ◽  
Kyle MARTIN ◽  
Zerina JOHANSON
Keyword(s):  
Soft Tissues ◽  
Developmental Stages ◽  
Model Organism ◽  
Model Organisms ◽  
Biological Research ◽  
Developmental Studies ◽  
Micro Computed Tomography ◽  
Computed Tomography Scanning ◽  
Cartilaginous Fishes ◽  
Tomography Scanning

ABSTRACTCartilaginous fishes have a long evolutionary history dating back 440 million years and include model organisms in a number of fields of biological research. However, comparative developmental studies of these organisms, particularly neuroanatomical investigations, still remain sparse. Here, pre-hatching to adult developmental stages of the Little Skate, Leucoraja erinacea, are investigated using micro-computed tomography scanning in conjunction with staining procedures designed to improve visualisation of soft tissues. Within the ear, the anatomy of the skeletal labyrinth changes during ontogeny and differs substantially from the underlying membranous system, contrary to previous observations in sharks. Additionally, substantial morphological remodelling characterises the parietal fossa, which appears initially as a massive and hook-like structure and subsequently becomes slender and surrounded by soft tissue. The sizes of the vestibular system and neurocranium increase isometrically from pre- to post-hatching phases, and then exponentially after the post-hatching stages.

scholarly journals Beam hardening artifacts in micro-computed tomography scanning can be reduced by X-ray beam filtration and the resulting images can be used to accurately measure BMD

Bone ◽  
2009 ◽  
Vol 45 (6) ◽  
pp. 1104-1116 ◽  
Author(s):  
Jeffrey A. Meganck ◽  
Kenneth M. Kozloff ◽  
Michael M. Thornton ◽  
Stephen M. Broski ◽  
Steven A. Goldstein
Keyword(s):  
Computed Tomography ◽  
Micro Computed Tomography ◽  
Beam Hardening ◽  
X Ray ◽  
Computed Tomography Scanning ◽  
Tomography Scanning

scholarly journals New information on the braincase and inner ear of Euparkeria capensis Broom: implications for diapsid and archosaur evolution

2016 ◽  
Vol 3 (7) ◽  
pp. 160072 ◽  
Author(s):  
Gabriela Sobral ◽  
Roland B. Sookias ◽  
Bhart-Anjan S. Bhullar ◽  
Roger Smith ◽  
Richard J. Butler ◽  
...  
Keyword(s):  
Lateral View ◽  
Micro Computed Tomography ◽  
Active Lifestyle ◽  
Pressure Relief ◽  
New Information ◽  
Computed Tomography Scanning ◽  
Anterior Semicircular Canal ◽  
First Time ◽  
Tomography Scanning ◽  
Hearing System

Since its discovery, Euparkeria capensis has been a key taxon for understanding the early evolution of archosaurs. The braincase of Euparkeria was described based on a single specimen, but much uncertainty remained. For the first time, all available braincase material of Euparkeria is re-examined using micro-computed tomography scanning. Contrary to previous work, the parabasisphenoid does not form the posterior border of the fenestra ovalis in lateral view, but it does bear a dorsal projection that forms the anteroventral half of the fenestra. No bone pneumatization was found, but the lateral depression of the parabasisphenoid may have been pneumatic. We propose that the lateral depression likely corresponds to the anterior tympanic recess present in crown archosaurs. The presence of a laterosphenoid is confirmed for Euparkeria . It largely conforms to the crocodilian condition, but shows some features which make it more similar to the avemetatarsalian laterosphenoid. The cochlea of Euparkeria is elongated, forming a deep cochlear recess. In comparison with other basal archosauromorphs, the metotic foramen is much enlarged and regionalized into vagus and recessus scalae tympani areas, indicating an increase in its pressure-relief mechanism. The anterior semicircular canal is extended and corresponds to an enlarged floccular fossa. These aspects of the braincase morphology may be related to the development of a more upright posture and active lifestyle. They also indicate further adaptations of the hearing system of Euparkeria to terrestriality.

scholarly journals The first mainland European Mesozoic click-beetle (Coleoptera: Elateridae) revealed by X-ray micro-computed tomography scanning of an Upper Cretaceous amber from Hungary

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Márton Szabó ◽  
Robin Kundrata ◽  
Johana Hoffmannova ◽  
Tamás Németh ◽  
Emese Bodor ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Upper Cretaceous ◽  
Micro Computed Tomography ◽  
Click Beetles ◽  
X Ray ◽  
The Past ◽  
Click Beetle ◽  
Computed Tomography Scanning ◽  
Source Of Information ◽  
Tomography Scanning

AbstractFossil bioinclusions in amber are invaluable source of information on the past evolution and diversity of various organisms, as well as on the paleoecosystems in general. The click-beetles, Elateridae, which originated and greatly diversified during the Mesozoic, are mostly known from the adpression-like fossils, and their diversity in the Cretaceous ambers is only poorly documented. In this study, we describe a new click-beetle based on an incomplete inclusion in ajkaite, an Upper Cretaceous (Santonian) amber from the Ajka Coal Formation from Hungary. We used X-ray micro-computed tomography scanning to reconstruct its morphology because it is deposited in an opaque piece of amber. Our results suggest that the newly described Ajkaelater merkli gen. et sp. nov. belongs to subfamily Elaterinae. It represents the first Mesozoic beetle reported from Hungary, and the first Mesozoic Elateridae formally described from mainland Europe. Our discovery supports an Eurasian distribution and diversification of Elaterinae already in the Cretaceous. The paleoenvironment of the Ajka Coal Formation agrees well with the presumed habitat preference of the new fossil taxon. The discovery of a presumably saproxylic click-beetle shed further light on the yet poorly known paleoecosystem of the Santonian present-day western Hungary.

scholarly journals Development of a micro-CT mouse holder for a femur defect mouse model

2020 ◽  
Author(s):  
Graeme R. Paul ◽  
Peter Schwilch ◽  
Esther Wehrle ◽  
Gisela A. Kuhn ◽  
Ralph Müller
Keyword(s):  
Computed Tomography ◽  
Mouse Model ◽  
Femur Fracture ◽  
Use Cases ◽  
Rigid Fixation ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Defect Healing ◽  
Computed Tomography Scanning ◽  
Tomography Scanning

AbstractCorrect fixation of an object is essential for accurate micro computed tomography scanning. In this document, we provide a motivation for, description of, and use cases for a mouse holder appropriate for holding an externally fixated mouse in femur fracture/defect healing experiments. In addition to rigid fixation, the holder provides heating and anaesthetic gas to ensure correct anaesthetic conditions for the animal. We provide the description and design files for a Scanco viva40 scanner, but with small changes, the holder can be used with other scanners.

Three-dimensional model of an ancient Egyptian falcon mummy skeleton

2015 ◽  
Vol 21 (4) ◽  
pp. 368-372 ◽  
Author(s):  
Anton Du Plessis ◽  
Ruhan Slabbert ◽  
Liani Colette Swanepoel ◽  
Johan Els ◽  
Gerrie J Booysen ◽  
...  
Keyword(s):  
Computed Tomography ◽  
3D Printing ◽  
Three Dimensional ◽  
Micro Computed Tomography ◽  
Three Dimensional Model ◽  
Content Type ◽  
3D Print ◽  
Ancient Egyptian ◽  
Computed Tomography Scanning ◽  
Tomography Scanning

Purpose – The purpose of this paper is to present the first detailed three-dimensional (3D) print from micro-computed tomography data of the skeleton of an ancient Egyptian falcon mummy. Design/methodology/approach – Radiographic analysis of an ancient Egyptian falcon mummy housed at Iziko Museums of South Africa was performed using non-destructive x-ray micro-computed tomography. A 1:1 physical replica of its skeleton was printed in a polymer material (polyamide) using 3D printing technology. Findings – The combination of high-resolution computed tomography scanning and rapid prototyping allowed us to create an accurate 1:1 model of a biological object hidden by wrappings. This model can be used to study skeletal features and morphology and also enhance exhibitions hosted within the museum. Originality/value – This is the first replica of its kind made of an ancient Egyptian falcon mummy skeleton. The combination of computed tomography scanning and 3D printing has the potential to facilitate scientific research and stimulate public interest in Egyptology.

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