scholarly journals Aspects of the gorgonopsian paleobiology: insights from the basicranium, occiput, osseous labyrinth and neuroanatomy of the immature gorgonopsian skull of Aloposaurus gracilis (Therapsida: Theriodontia: Gorgonopsia)

2016 ◽  
Author(s):  
Ricardo M Araujo ◽  
Vincent Fernandez ◽  
Michael J Polcyn ◽  
Jörg Fröbisch ◽  
Rui M.S. Martins
Keyword(s):  
Computed Tomography ◽  
Semicircular Canal ◽  
Phase Contrast ◽  
Cranial Nerves ◽  
Brain Anatomy ◽  
Micro Computed Tomography ◽  
Horizontal Semicircular Canal ◽  
Head Posture ◽  
The Past ◽  
The Brain

Synapsida, the clade including therapsids and thus also mammals, is one of the two major branches of amniotes. Organismal design, with modularity as a concept, offers insights into the evolution of therapsids, a group that experienced profound anatomical transformations throughout the past 270Ma, eventually leading to the evolution of the mammalian bauplan. However, the anatomy of some therapsid groups remains obscure. Gorgonopsian braincase anatomy remains poorly known, and aspects of their brain anatomy, cranial nerves and vasculature, osseous labyrinth persist unknown. By using propagation phase contrast synchrotron micro-computed tomography, we scanned GPIT/RE/7124, a specimen previously reported as Aloposaurus gracilis. We explored the anatomy of the braincase and rendered the anatomy of the various skull cavities. Notably, we found that there is a separate ossification between what was previously referred as the “parasphenoid” and the basioccipital. This element is reinterpreted as a posterior ossification of the basisphenoid, the basi-postsphenoid. Additionally the previously called “parasphenoid” is in fact the co-ossification of the dermal parasphenoid and the endochondral basi-presphenoid. The anatomy of the osseous labyrinth is rendered in detail, revealing a unique discoid morphology of the horizontal semicircular canal, rather than toroidal, probably due to architectural contraints of the ossification of the opisthotic and supraoccipital. In addition, the orientation of the horizontal semicircular canal suggests an anteriorly tilted alert head posture. The morphology of the brain endocast is in accordance with the more reptilian endocast shape of other non-mammaliaform neotherapsids.

scholarly journals Aspects of gorgonopsian paleobiology and evolution: insights from the basicranium, occiput, osseous labyrinth, vasculature, and neuroanatomy

2017 ◽  
Author(s):  
Ricardo M Araujo ◽  
Vincent Fernandez ◽  
Michael J Polcyn ◽  
Jörg Fröbisch ◽  
Rui M.S. Martins
Keyword(s):  
Semicircular Canal ◽  
Phase Contrast ◽  
Cranial Nerves ◽  
Detailed Examination ◽  
Micro Computed Tomography ◽  
Horizontal Semicircular Canal ◽  
The Past ◽  
Architectural Constraints ◽  
The Brain ◽  
Immature Specimen

Synapsida, the clade including therapsids and thus also mammals, is one of the two major branches of amniotes. Organismal design, with modularity as a concept, offers insights into the evolution of therapsids, a group that experienced profound anatomical transformations throughout the past 270Ma, eventually leading to the evolution of the mammalian bauplan. However, the anatomy of some therapsid groups remains obscure. Gorgonopsian braincase anatomy is poorly known and many anatomical aspects of the brain, cranial nerves, vasculature, and osseous labyrinth, remain unclear. We analyzed two gorgonopsian specimens, GPIT/RE/7124 and GPIT/RE/7119, using propagation phase contrast synchrotron micro-computed tomography. The lack of fusion between many basicranial and occipital bones in the immature specimen GPIT/RE/7124 allowed us to reconstruct its anatomy and ontogenetic sequence in comparison with the mature GPIT/RE/7119. We examined the braincase and rendered various skull cavities. Notably, there is a separate ossification between what was previously referred to as the “parasphenoid” and the basioccipital. We reinterpreted this element as a posterior ossification of the basisphenoid: the basipostsphenoid. Moreover, the “parasphenoid” is a co-ossification of the dermal parasphenoid and the endochondral basipresphenoid. Our detailed examination of the osseous labyrinth reveals a unique discoid, rather than toroidal, morphology of the horizontal semicircular canal that probably results from architectural constraints of the opisthotic and supraoccipital ossifications. In addition, the orientation of the horizontal semicircular canal suggests that gorgonopsians had an anteriorly tilted alert head posture. The morphology of the brain endocast is in accordance with the more reptilian endocast shape of other non-mammaliaform neotherapsids.

scholarly journals Aspects of gorgonopsian paleobiology and evolution: insights from the basicranium, occiput, osseous labyrinth, vasculature, and neuroanatomy

2017 ◽  
Author(s):  
Ricardo M Araujo ◽  
Vincent Fernandez ◽  
Michael J Polcyn ◽  
Jörg Fröbisch ◽  
Rui M.S. Martins
Keyword(s):  
Semicircular Canal ◽  
Phase Contrast ◽  
Cranial Nerves ◽  
Detailed Examination ◽  
Micro Computed Tomography ◽  
Horizontal Semicircular Canal ◽  
The Past ◽  
Architectural Constraints ◽  
The Brain ◽  
Immature Specimen

Synapsida, the clade including therapsids and thus also mammals, is one of the two major branches of amniotes. Organismal design, with modularity as a concept, offers insights into the evolution of therapsids, a group that experienced profound anatomical transformations throughout the past 270Ma, eventually leading to the evolution of the mammalian bauplan. However, the anatomy of some therapsid groups remains obscure. Gorgonopsian braincase anatomy is poorly known and many anatomical aspects of the brain, cranial nerves, vasculature, and osseous labyrinth, remain unclear. We analyzed two gorgonopsian specimens, GPIT/RE/7124 and GPIT/RE/7119, using propagation phase contrast synchrotron micro-computed tomography. The lack of fusion between many basicranial and occipital bones in the immature specimen GPIT/RE/7124 allowed us to reconstruct its anatomy and ontogenetic sequence in comparison with the mature GPIT/RE/7119. We examined the braincase and rendered various skull cavities. Notably, there is a separate ossification between what was previously referred to as the “parasphenoid” and the basioccipital. We reinterpreted this element as a posterior ossification of the basisphenoid: the basipostsphenoid. Moreover, the “parasphenoid” is a co-ossification of the dermal parasphenoid and the endochondral basipresphenoid. Our detailed examination of the osseous labyrinth reveals a unique discoid, rather than toroidal, morphology of the horizontal semicircular canal that probably results from architectural constraints of the opisthotic and supraoccipital ossifications. In addition, the orientation of the horizontal semicircular canal suggests that gorgonopsians had an anteriorly tilted alert head posture. The morphology of the brain endocast is in accordance with the more reptilian endocast shape of other non-mammaliaform neotherapsids.

scholarly journals Aspects of gorgonopsian paleobiology and evolution: insights from the basicranium, occiput, osseous labyrinth, vasculature, and neuroanatomy

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3119 ◽  
Author(s):  
Ricardo Araújo ◽  
Vincent Fernandez ◽  
Michael J. Polcyn ◽  
Jörg Fröbisch ◽  
Rui M.S. Martins
Keyword(s):  
Semicircular Canal ◽  
Phase Contrast ◽  
Cranial Nerves ◽  
Micro Computed Tomography ◽  
Horizontal Semicircular Canal ◽  
Lack Of Fusion ◽  
The Past ◽  
Architectural Constraints ◽  
The Brain ◽  
Immature Specimen

Synapsida, the clade including therapsids and thus also mammals, is one of the two major branches of amniotes. Organismal design, with modularity as a concept, offers insights into the evolution of therapsids, a group that experienced profound anatomical transformations throughout the past 270 Ma, eventually leading to the evolution of the mammalian bauplan. However, the anatomy of some therapsid groups remains obscure. Gorgonopsian braincase anatomy is poorly known and many anatomical aspects of the brain, cranial nerves, vasculature, and osseous labyrinth, remain unclear. We analyzed two gorgonopsian specimens, GPIT/RE/7124 and GPIT/RE/7119, using propagation phase contrast synchrotron micro-computed tomography. The lack of fusion between many basicranial and occipital bones in GPIT/RE/7124, which is an immature specimen, allowed us to reconstruct its anatomy and ontogenetic sequence, in comparison with the mature GPIT/RE/7119, in great detail. We explored the braincase and rendered various skull cavities. Notably, we found that there is a separate ossification between what was previously referred to as the “parasphenoid” and the basioccipital. We reinterpreted this element as a posterior ossification of the basisphenoid: the basipostsphenoid. Moreover, we show that the previously called “parasphenoid” is in fact the co-ossification of the dermal parasphenoid and the endochondral basipresphenoid. In line with previous descriptions, the anatomy of the osseous labyrinth is rendered in detail, revealing a unique discoid morphology of the horizontal semicircular canal, rather than toroidal, probably due to architectural constraints of the ossification of the opisthotic and supraoccipital. In addition, the orientation of the horizontal semicircular canal suggests that gorgonopsians had an anteriorly tilted alert head posture. The morphology of the brain endocast is in accordance with the more reptilian endocast shape of other non-mammaliaform neotherapsids.

scholarly journals Ontogenetic braincase development in Psittacosaurus lujiatunensis (Dinosauria: Ceratopsia) using micro-computed tomography

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7217 ◽  
Author(s):  
Claire M. Bullar ◽  
Qi Zhao ◽  
Michael J. Benton ◽  
Michael J. Ryan
Keyword(s):  
Computed Tomography ◽  
Semicircular Canal ◽  
Morphological Changes ◽  
Relative Reduction ◽  
Growth Stages ◽  
Ontogenetic Changes ◽  
Micro Computed Tomography ◽  
Horizontal Semicircular Canal ◽  
Computed Tomography Scans ◽  
Key Events

Ontogenetic sequences are relatively rare among dinosaurs, with Ceratopsia being one of the better represented clades, and especially among geologically earlier forms, such as Psittacosaurus. Psittacosaurus is a small, bipedal basal ceratopsian abundant in the Lower Cretaceous deposits of Asia, whose cranial and endocranial morphology has been well studied, but only cursory details have been published on the bones surrounding the brain. Using reconstructions created from micro-computed tomography scans of well-preserved skulls from the Barremian–Aptian Yixian Formation, China, we document morphological changes in the braincase of Psittacosaurus lujiatunensis through three growth stages, hatchling, juvenile, and adult, thus providing the first detailed study of ceratopsian braincase morphology through ontogeny. Notable ontogenetic changes in the braincase of P. lujiatunensis include a dramatic relative reduction in size of the supraoccipital, an increase in the lateral expansion of the paroccipital processes and a decrease in the angle between the lateral semicircular canal and the palatal plane. These ontogenetic morphological changes in the braincase relate to expansion of the cranium and brain through growth, as well as reflecting the switch from quadrupedal juveniles to bipedal adults as documented in the changing orientation of the horizontal semicircular canal through ontogeny. Recognition of these patterns in a basal ceratopsian has implications for understanding key events in later ceratopsian evolution, such as the development of the parieto-squamosal frill in derived neoceratopsians.

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.

High-Resolution Radiography for Detecting and Measuring Micron-Scale Features

2004 ◽  
Author(s):  
Daniel H. Morse ◽  
Arlyn J. Antolak ◽  
Bernice E. Mills
Keyword(s):  
Computed Tomography ◽  
Composite Materials ◽  
Phase Contrast ◽  
Three Dimensional ◽  
Conventional Radiography ◽  
Small Scale ◽  
Micro Computed Tomography ◽  
Contrast Imaging ◽  
X Ray ◽  
Projection Radiography

X-ray radiography has long been recognized as a valuable tool for detecting internal features and flaws. Recent developments in microfabrication and composite materials have extended inspection requirements to the resolution limits of conventional radiography. Our work has been directed toward pushing both detection and measurement capabilities to a smaller scale. Until recently, we have used conventional contact radiography, optimized to resolve small features. With the recent purchase of a nano-focus (sub-micron) x-ray source, we are now investigating projection radiography, phase contrast imaging and micro-computed tomography (μ-CT). Projection radiography produces a magnified image that is limited in spatial resolution mainly by the source size, not by film grain size or detector pixel size. Under certain conditions phase contrast can increase the ability to resolve small features such as cracks, especially in materials with low absorption contrast. Micro-computed tomography can provide three-dimensional measurements on a micron scale and has been shown to provide better sensitivity than simple radiographs. We have included applications of these techniques to small-scale measurements not easily made by mechanical or optical means. Examples include void detection in meso-scale nickel MEMS parts, measurement of edge profiles in thick gold lithography masks, and characterization of the distribution of phases in composite materials. Our work, so far, has been limited to film.

Cat Brain Neuroanatomy using Cryosectioning, Magnetic Resonance and Computed Tomography Imaging Modalities

2020 ◽  
Keyword(s):  
Computed Tomography ◽  
Magnetic Resonance ◽  
Neurological Diseases ◽  
Gross Anatomy ◽  
Diagnosis And Treatment ◽  
Imaging Modalities ◽  
Brain Anatomy ◽  
The Common ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Magnetic resonance imaging (MRI) and computed tomography (CT) imaging modalities are invaluable for the diagnosis and treatment of neurological diseases. This study aimed to correlate the anatomical sectional data of the cats’ brain to the sections obtained by both MRI and CT examination. The present work was conducted on four cats, 1-4 years old, weighing about (2.5 to 3.5) kg admitted to the hospital with terminal diseases not related to the nervous system. The anatomical sections were taken at intervals of 5 mm, on different planes such as sagittal, frontal and transverse. The sections were obtained, following humane euthanasia, from frozen heads and identified according to the previous literatures. The images from both MRI and CT were compared with those of the gross anatomy sections and different structures were identified. To identify arterial distribution in the brain, one cat was injected with red latex through the common carotid artery, frozen, and sectioned. For vascular imaging, the same cat was examined by MRI after intravenous injection of contrast media. The descriptions of the brain anatomy from the MRI and CT images will act as a basis for the diagnosis and treatment of different neurological diseases in cat. This will assist veterinarians and radiologists in the identification of various nervous lesions related to the brain.

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