scholarly journals The dentary ofAustralovenator wintonensis(Theropoda, Megaraptoridae); implications for megaraptorid dentition

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1512 ◽  
Author(s):  
Matt A. White ◽  
Phil R. Bell ◽  
Alex G. Cook ◽  
Stephen F. Poropat ◽  
David A. Elliott
Keyword(s):  
Computed Tomography ◽  
Cross Section ◽  
Three Dimensional ◽  
Dental Morphology ◽  
Tooth Morphology ◽  
Dentary Tooth ◽  
Qualitative Characters ◽  
Maxillary Dentition ◽  
Accurate Reconstruction

Megaraptorid theropods were an enigmatic group of medium-sized predatory dinosaurs, infamous for the hypertrophied claw on the first manual digit. Megaraptorid dentition is largely restricted to isolated teeth found in association with skeletal parts; however, thein situmaxillary dentition ofMegaraptorwas recently described. A newly discovered right dentary pertaining to theAustralovenatorholotype preservesin situdentition, permitting unambiguous characterisation of the dentary tooth morphology. The new jaw is virtually complete, with an overall elongate, shallow profile, and fifteen visiblein situteeth at varying stages of eruption.In situteeth confirmAustralovenatorexhibited modest pseudoheterodonty, recurved lateral teeth with a serrate distal carina and reduced mesial carina, similar to other megaraptorids.Australovenatoralso combines of figure-of-eight basal cross-section with a lanceolate shape due to the presence of labial and lingual depressions and the lingual twist of the distal carina. Computed tomography and three-dimensional imagery provided superior characterisation of the dentary morphology and enabled an accurate reconstruction to a pre-fossilised state. The newly established dental morphology also afforded re-evaluation of isolated theropod teeth discovered at theAustralovenatorholotype locality and from several additional Winton Formation localities. The isolated Winton teeth are qualitatively and quantitatively similar to thein situdentary teeth ofAustralovenator, but are also morphometrically similar to Abelisauridae, Allosauridae, Coelophysoidea, Megalosauridae and basal Tyrannosauroidea. Qualitative characters, however, clearly distinguish the teeth ofAustralovenatorand the isolated Winton teeth from all other theropods. Evidence from teeth suggests megaraptorids were the dominant predators in the Winton Formation, which contrasts with other penecontemporaneous Gondwanan ecosystems.

In Situ Testing Using Synchrotron Radiation Computed Tomography in Materials Research

MRS Advances ◽  
2019 ◽  
Vol 4 (51-52) ◽  
pp. 2831-2841
Author(s):  
Xinchen Ni ◽  
Nathan K. Fritz ◽  
Brian L. Wardle
Keyword(s):  
Computed Tomography ◽  
Synchrotron Radiation ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Time Lapse ◽  
In Situ Testing ◽  
Temporal Dimension ◽  
Analysis Measurement ◽  
Materials Research

ABSTRACTHigh resolution (< 1 µm) computed tomography is an attractive tool in materials research due to its ability to non-destructively visualize the three-dimensional internal microstructures of the material. Recently, this technique has been further empowered by adding a fourth (temporal) dimension to study the time-lapse material response under load. Such studies are referred to as four-dimensional or in situ testing. In this snapshot review, we highlight three representative examples of in situ testing using synchrotron radiation computed tomography (SRCT) for composites failure analysis, measurement of local corrosion rate in alloys, and visualization and quantification of electrochemical reactions in lithium-ion batteries, as well as forward-looking integration of machine learning with in situ CT. Lastly, the future opportunities and challenges of in situ SRCT testing are discussed.

Advances in In Situ SiC Growth Analysis Using Cone Beam Computed Tomography

2019 ◽  
Vol 963 ◽  
pp. 5-9 ◽  
Author(s):  
Michael Salamon ◽  
Matthias Arzig ◽  
Norman Uhlmann ◽  
Peter J. Wellmann
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
In Situ Monitoring ◽  
Material Structure ◽  
Two Dimensional ◽  
Accurate Analysis ◽  
X Ray ◽  
Characteristic Features ◽  
Third Dimension

Computed Tomography is becoming a valuable method for the in-situ monitoring of vapor grown silicon carbide single crystals [1]. Already the two-dimensional X-ray radiography has shown the potential of surveilling the growth process [2] and its characteristic features like the evolution of the facet, the crystal volume or the source material structure from one imaging plane. Even though the demands on imaging capability of the applied X-ray components used for a tomographic analysis are higher than for two-dimensional imaging, the extension of this method to the third dimension is highly beneficial. It allows investigating the full geometry and three-dimensional location of the features and by this provides a more accurate analysis. In this contribution we present the physical characteristics and the latest advances of our technique for the visualization of facets.

Proton computed tomography

2015 ◽  
Vol 30 (17) ◽  
pp. 1540024 ◽  
Author(s):  
Martina Bucciantonio ◽  
Fabio Sauli
Keyword(s):  
Computed Tomography ◽  
Diagnostic Method ◽  
Three Dimensional ◽  
Particle Beams ◽  
Basic Principles ◽  
Charged Particle Beams ◽  
Experimental Systems ◽  
Proton Computed Tomography ◽  
Long Time

Proton computed tomography (pCT) is a diagnostic method capable of in situ imaging the three-dimensional density distribution in a patient before irradiation with charged particle beams. Proposed long time ago, this technology has been developed by several groups, and may become an essential tool for advanced quality assessment in hadrontherapy. We describe the basic principles of the method, its performance and limitations as well as provide a summary of experimental systems and of results achieved.

Measurement of three-dimensional lung tree structures by using computed tomography

1995 ◽  
Vol 79 (5) ◽  
pp. 1687-1697 ◽  
Author(s):  
S. A. Wood ◽  
E. A. Zerhouni ◽  
J. D. Hoford ◽  
E. A. Hoffman ◽  
W. Mitzner
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Central Axis ◽  
Segment Length ◽  
Cross Sectional ◽  
Tree Structures ◽  
Branch Segment ◽  
Tomography Data

A method was devised to computationally segment and measure three-dimensional pulmonary trees in situ. Bronchi and pulmonary vessels were computationally extracted from volumetric computed tomography data based on radiopacity differences between airway wall and airway lumen and between blood and parenchyma, respectively. The tree was reduced to a central axis to facilitate measurement of branch segment length and angle. Cross-sectional area was measured on a reconstructed computed tomography slice perpendicular to this central axis. The method was validated by scanning two Plexiglas phantoms and an intact lung. Reconstructed diameters in the phantoms were accurate for branches > 2 mm. In the lung airway branches between 1 and 2 mm in diameter were often unresolved when their angle of orientation with respect to the axis of the scanner was > 45 degrees. However, if a branch was resolved, its reconstructed diameter was little affected by orientation. This method represents a significant improvement in the analysis of complex pulmonary structures in three dimensions.

In Situ Visualization and Quantification of Three-Dimensional Root System Architecture and Growth Using X-Ray Computed Tomography

2014 ◽  
Vol 13 (8) ◽  
pp. vzj2014.03.0024 ◽  
Author(s):  
Nicolai Koebernick ◽  
Ulrich Weller ◽  
Katrin Huber ◽  
Steffen Schlüter ◽  
Hans-Jörg Vogel ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Root System ◽  
System Architecture ◽  
Three Dimensional ◽  
Root System Architecture ◽  
X Ray ◽  
In Situ Visualization ◽  
X Ray Computed

Three dimensional imaging of plant roots in situ with X-ray Computed Tomography

1997 ◽  
Vol 189 (2) ◽  
pp. 167-179 ◽  
Author(s):  
D.A. Heeraman ◽  
J.W. Hopmans ◽  
V. Clausnitzer
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Plant Roots ◽  
Three Dimensional Imaging ◽  
X Ray ◽  
X Ray Computed
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