Computer Science, Engineering and Mathematics - Collected Works

Permanent URI for this collection


Recent Submissions

Now showing 1 - 20 of 231
  • Item
    Vitamin A and marbling attributes: Intramuscular fat hyperplasia effects in cattle
    (Elsevier, 2017-11-21) Kruk, Zbigniew A; Bottema, Murk Jan; Reyes-Veliz, Luisa; Forder, Rebecca; Pitchford, Wayne; Bottema, Cynthia D K
    Twenty Angus steers were fed a diet low in β-carotene and vitamin A for 10 months. Ten steers were supplemented with vitamin A weekly, while the other ten steers did not receive any additional vitamin A. The results demonstrated that the restriction of vitamin A intake increased intramuscular fat (IMF) by 46%. This was a function of the total number of marbling flecks increasing by 22% and the average marbling fleck size increasing by 14%. Vitamin A restriction resulted in marbling flecks that were less branched (22%) and slightly more round (4%) with an increased minor axis length (7%). However, restricting vitamin A did not affect the size of the intramuscular or subcutaneous adipocyte cells or the subcutaneous fat depth. The results suggest that vitamin A affects the amount of marbling and other attributes of the marbling flecks due to hyperplasia rather than hypertrophy. This may explain why vitamin A restriction specifically affects IMF rather than subcutaneous fat deposition.
  • Item
    Electrically Sorted Single-Walled Carbon Nanotubes-Based Electron Transporting Layers for Perovskite Solar Cells
    (Elsevier, 2019-03-20) Bati, Abdulaziz S R; Yu, Le Ping; Tawfik, Sherif Abdulkader; Spencer, Michelle J S; Shaw, Paul E; Batmunkh, Munkhbayar; Shapter, Joseph George
    Incorporation of as prepared single-walled carbon nanotubes (SWCNTs) into the electron transporting layer (ETL) is an effective strategy to enhance the photovoltaic performance of perovskite solar cells (PSCs). However, the fundamental role of the SWCNT electrical types in the PSCs is not well understood. Herein, we prepared semiconducting (s-) and metallic (m-) SWCNT families and integrated them into TiO2 photoelectrodes of the PSCs. Based on experimental and theoretical studies, we found that the electrical type of the nanotubes plays an important role in the devices. In particular, the mixture of s-SWCNTs and m-SWCNTs (2:1 w/w)-based PSCs exhibited a remarkable efficiency of up to 19.35%, which was significantly higher than that of the best control cell (17.04%). In this class of PSCs, semiconducting properties of s-SWCNTs play a critical role in extracting and transporting electrons, whereas m-SWCNTs provide high conductance throughout the electrode.
  • Item
    Start-up plane Poiseuille flow of a Bingham fluid
    (Elsevier, 2018-10-27) Huilgol, Raja Ramesh; Alexandrou, Andreas N; Georgiou, Georgios C
    The start-up flow of a Bingham plastic in a channel is considered and Safronchik’s solution [1] for the initial evolution of the yield surface and the core velocity is revisited. Stricter time bounds for the validity of the above solution are derived and the solution is extended to include the velocity profile in the evolving yielded zone. Comparisons are made with another approximate solution derived under the assumption that the velocity in the yielded zone is parabolic adjusting with the evolving yield surface. This approximation performs well for small values of the yield stress, or, equivalently, for large values of the imposed pressure gradient.
  • Item
    Experimental and numerical investigation of blade–tower interaction noise
    (Elsevier, 2018-12-04) Zajamsek, Branko; Yauwenas, Yendrew; Doolan, Con J; Hansen, Kristy L; Timchenko, Victoria; Reizes, John; Hansen, Colin H
    This paper describes the generation of blade–tower interaction (BTI) noise from upwind turbines and pylon-mounted fans using a combination of experimental and numerical means. An experimental rotor-rig was used in an anechoic chamber to obtain BTI acoustic data under controlled conditions. A computational model, based on the solution of the unsteady Reynolds Averaged Navier Stokes (URANS) equations and Curle's acoustic analogy, was used to describe the generation of fan and simplistic model of wind turbine BTI noise by the rotor-rig. For both the fan and model wind turbine case, the tower was found to be a more significant source of BTI noise than rotor blades. The acoustic waveforms for both turbine and fan are similar; however, in the case of the turbine, the blade contribution reinforces that from the tower, while in the case of a fan, there is some cancellation between the tower source and the blade source. This behavior can be explained by the unsteady aerodynamics occurring during BTI.
  • Item
    The Oscillatory Adsorption of Organosilane Films on Aluminium Oxide: Film Morphology using Auger Electron Spectromicroscopy
    (Elsevier, 2019-01-03) Sims, Ruby A; Harmer-Bassell, Sarah L; Quinton, Jamie Scott
    The morphology of Propyltrimethoxysilane films during the oscillatory growth mechanism is shown using Auger Electron Spectromicroscopy. While the link between oligomerisation of silane molecules on the substrate and the oscillatory growth mechanism has been proposed previously, here for the first time we show the presence of silane film islands through Auger Electron Spectromicroscopy elemental mapping of the substrate. Monitoring the morphology of the film at key peaks and throughout along the oscillatory curve reveals the formation of a stable thin, homogenous film along with the presence of islands approximately 20μm in diameter, whose numbers vary collectively during the adsorption/desorption mechanism. The measurable oscillations in silane substrate coverage has been directly linked to the repeated adsorption and desorption of silane islands on the aluminium substrate. The consequence of this mechanism is such that Propyltrimethoxysilane films behave most like a monolayer during the early stages of film growth, prior to siloxane oligomerisation.
  • Item
    The effect of axial compression and distraction on cervical facet mechanics during anterior shear, flexion, axial rotation, and lateral bending motions
    (Elsevier, 2018-12-05) Quarrington, Ryan D; Costi, John Jack; Freeman, Brian J C; Jones, Claire F
    The subaxial cervical facets are important load-bearing structures, yet little is known about their mechanical response during physiological or traumatic intervertebral motion. Facet loading likely increases when intervertebral motions are superimposed with axial compression forces, increasing the risk of facet fracture. The aim of this study was to measure the mechanical response of the facets when intervertebral axial compression or distraction is superimposed on constrained, non-destructive shear, bending and rotation motions. Twelve C6/C7 motion segments (70 ± 13 yr, nine male) were subjected to constrained quasi-static anterior shear (1 mm), axial rotation (4°), flexion (10°), and lateral bending (5°) motions. Each motion was superimposed with three axial conditions: (1) 50 N compression; (2) 300 N compression (simulating neck muscle contraction); and, (3) 2.5 mm distraction. Angular deflections, and principal and shear surface strains, of the bilateral C6 inferior facets were calculated from motion-capture data and rosette strain gauges, respectively. Linear mixed-effects models (α = 0.05) assessed the effect of axial condition. Minimum principal and maximum shear strains were largest in the compressed condition for all motions except for maximum principal strains during axial rotation. For right axial rotation, maximum principal strains were larger for the contralateral facets, and minimum principal strains were larger for the left facets, regardless of axial condition. Sagittal deflections were largest in the compressed conditions during anterior shear and lateral bending motions, when adjusted for facet side.
  • Item
    Continuous flow thin film microfluidic mediated nano-encapsulation of fish oil
    (Elsevier, 2018-12-26) He, Shan; Joseph, Nikita; Luo, Xuan; Raston, Colin L
    A facile process has been developed for the encapsulation of fish oil using a thin film vortex fluidic device (VFD) operating under continuous flow, allowing control over the size of the encapsulated particles which are spheroidal in shape with diameters ranging from 50 to 250 nm. This microfluidic platform simplifies the processing procedure of water-in-oil-in-water (w/o/w) encapsulation, as now a time and cost saving one-step process devoid of any organic solvents, in contrast to the conventional homogenization process which is inherently complex, involving multiple-steps and the use of organic solvents. Moreover, use of homogenization (as a benchmark to encapsulate fish oil) afforded much larger macro-particles, ranging in size from 2 to 4 μm. Smaller encapsulated particles fabricated using VFD processing could lead to improved absorption from fish oil. Overall, VFD processing provides a new alternative bottom–up approach to easy, scalable processing, without the need for organic solvents which are counterproductive in the food industry.
  • Item
    Detecting synchrony in EEG: A comparative study of functional connectivity measures
    (Elsevier, 2018-12-11) Bakhshayesh, Hanieh; Fitzgibbon, Sean Patrick; Janani, Azin; Grummett, Tyler S; Pope, Kenneth
    In neuroscience, there is considerable current interest in investigating the connections between different parts of the brain. EEG is one modality for examining brain function, with advantages such as high temporal resolution and low cost. Many measures of connectivity have been proposed, but which is the best measure to use? In this paper, we address part of this question: which measure is best able to detect connections that do exist, in the challenging situation of non-stationary and noisy data from nonlinear systems, like EEG. This requires knowledge of the true relationship between signals, hence we compare 26 measures of functional connectivity on simulated data (unidirectionally coupled Hénon maps, and simulated EEG). To determine whether synchrony is detected, surrogate data were generated and analysed, and a threshold determined from the surrogate ensemble. No measure performed best in all tested situations. The correlation and coherence measures performed best on stationary data with many samples. S-estimator, correntropy, mean-phase coherence (Hilbert), mutual information (kernel), nonlinear interdependence (S) and nonlinear interdependence (N) performed most reliably on non-stationary data with small to medium window sizes. Of these, correlation and S-estimator have execution times that scale slower with the number of channels and the number of samples.
  • Item
    Plio-Pleistocene diversification and biogeographic barriers in southern Australia reflected in the phylogeography of a widespread and common lizard species
    (Elsevier, 2018-12-13) Ansari, Mina Hojat; Cooper, Steven J B; Schwarz, Michael Philip; Ebrahimi, Mehregan; Dolman, Gaynor; Reinberger, Leigh; Saint, Kathleen M; Donnellan, Steve C; Bull, Christopher Michael; Gardner, Michael George
    Palaeoclimatic events and biogeographical processes since the mid-Tertiary have played an important role in shaping the evolution and distribution of Australian fauna. However, their impacts on fauna in southern and arid zone regions of Australia are not well understood. Here we investigate the phylogeography of an Australian scincid lizard, Tiliqua rugosa, across southern Australia using mitochondrial DNA (mtDNA) and 11 nuclear DNA markers (nuDNA), including nine anonymous nuclear loci. Phylogenetic analyses revealed three major mtDNA lineages within T. rugosa, geographically localised north and south of the Murray River in southern Australia, and west of the Nullarbor Plain. Molecular variance and population analyses of both mtDNA and nuDNA haplotypes revealed significant variation among the three populations, although potential introgression of nuDNA markers was also detected for the Northern and Southern population. Coalescent times for major mtDNA lineages coincide with an aridification phase, which commenced after the early Pliocene and increased in intensity during the Late Pliocene-Pleistocene. Species distribution modelling and a phylogeographic diffusion model suggest that the range of T. rugosa may have contracted during the Last Glacial Maximum and the locations of optimal habitat appear to coincide with the geographic origin of several distinct mtDNA lineages. Overall, our analyses suggest that Plio-Pleistocene climatic changes and biogeographic barriers associated with the Nullarbor Plain and Murray River have played a key role in shaping the present-day distribution of genetic diversity in T. rugosa and many additional ground-dwelling animals distributed across southern Australia.
  • Item
    Virtual trial to evaluate the robustness of cementless femoral stems to patient and surgical variation
    (Elsevier, 2018-11-15) Al-Dirini, Rami M A; Martelli, Saulo; O'Rourke, Dermot; Huff, Daniel; Zhang, Ju; Clement, John G; Besier, Thor; Taylor, Mark
    Primary stability is essential for the success of cementless femoral stems. In this study, patient specific finite element (FE) models were used to assess changes in primary stability due to variability in patient anatomy, bone properties and stem alignment for two commonly used cementless femoral stems, Corail® and Summit® (DePuy Synthes, Warsaw, USA). Computed-tomography images of the femur were obtained for 8 males and 8 females. An automated algorithm was used to determine the stem position and size which minimized the endo-cortical space, and then span the plausible surgical envelope of implant positions constrained by the endo-cortical boundary. A total of 1952 models were generated and ran, each with a unique alignment scenario. Peak hip contact and muscle forces for stair climbing were scaled to the donor’s body weight and applied to the model. The primary stability was assessed by comparing the implant micromotion and peri-prosthetic strains to thresholds (150 μm and 7000 µε, respectively) above which fibrous tissue differentiation and bone damage are expected to prevail. Despite the wide range of implant positions included, FE prediction were mostly below the thresholds (medians: Corail®: 20–74 µm and 1150–2884 µε, Summit®: 25–111 µm and 860–3010 µε), but sensitivity of micromotion and interfacial strains varied across femora, with the majority being sensitive (p < 0.0029) to average bone mineral density, cranio-caudal angle, post-implantation anteversion angle and lateral offset of the femur. The results confirm the relationship between implant position and primary stability was highly dependent on the patient and the stem design used.
  • Item
    Changes in Media Portrayal of Human-wildlife Conflict During Successive Fatal Shark Bites
    (Wolters Kluwer, 2018-07-02) Sabatier, Etienne; Huveneers, Charlie
    Encounters between humans and wildlife that result in human fatalities can generate public anxiety and increase pressure on conservation managers and governments for risk mitigation. Low probability-high consequence events such as shark bites on humans attract substantial media attention for short time periods, but how the media react when several of these rare but fatal events occur in quick succession has seldom been subject to quantitative analysis. Understanding media portrayal of such encounters is important because it both reflects and influences public perceptions of risks, mitigation measures, and conservation policies. This study examined media portrayals of sharks between 2011 and 2013 in the state of Western Australia during which six shark bites resulting in fatalities occurred. We analysed 361 shark-related articles published in major Western Australian newspapers over 26 months to trace changes in media reporting about sharks prior to, during, and after the six fatalities. The findings indicate that when rare, but fatal human-wildlife events occur in quick succession, negative framing by media of wildlife behaviour and threats can exaggerate public anxiety about the pervasive presence of wildlife predators and high risk of human fatalities. The study highlights the need for government agencies and conservation scientists to better engage with media to provide accurate and effective information and advice to swimmers and surfers about shark ecology and behaviour.
  • Item
    Laser-Ablated Vortex Fluidic-Mediated Synthesis of Superparamagnetic Magnetite Nanoparticles in Water Under Flow
    (ACS Publications, 2018-09-14) Luo, Xuan; Al-Antaki, Ahmed H M; Alharbi, Thaar M D; Hutchison, Wayne D; Zou, Yi-chao; Zou, Jin; Sheehan, Antony; Zhang, Wei; Raston, Colin L
    Selective formation of only one iron oxide phase is a major challenge in conventional laser ablation process, as is scaling up the process. Herein, superparamagnetic single-phase magnetite nanoparticles of hexagonal and spheroidal-shape, with an average size of ca. 15 nm, are generated by laser ablation of bulk iron metal at 1064 nm in a vortex fluidic device (VFD). This is a one-step continuous flow process, in air at ambient pressure, with in situ uptake of the nanoparticles in the dynamic thin film of water in the VFD. The process minimizes the generation of waste by avoiding the need for any chemicals or surfactants and avoids time-consuming purification steps in reducing any negative impact of the processing on the environment.
  • Item
    Development of Lateral Prestress in High-Strength Concrete-Filled FRP Tubes
    (IOP Publishng, 2018) Vincent, Thomas; Ozbakkaloglu, Togay
    This paper reports on an experimental investigation into the axial and lateral strain development of fiber reinforced polymer (FRP) confined high-strength concrete (HSC) with prestressed FRP shells. A total of 24 aramid FRP (AFRP)-confined concrete specimens were manufactured as concrete-filled FRP tubes (CFFTs) with instrumentation to measure the strain variations during application of prestress, removal of end constraints and progressive prestress losses. Prestressed CFFT specimens were prepared with three different dose rates of expansive mineral admixture to create a range of lateral prestress applied to AFRP tubes manufactured with sheet thicknesses of 0.2 or 0.3 mm/ply and referred to as lightly- or well-confined, respectively. In addition to these three levels of prestress, non-prestressed companion specimens were manufactured and tested to determine baseline performance. The experimental results from this study indicate that lateral prestressing of CFFTs manufactured with HSC can be achieved by varying the expansive mineral admixture dose rate with a lateral prestress of up to 7.3 MPa recorded in this study. Significant strain variations were measured during removal of the end constraints with up to 700 microstrain recorded in the axial direction. Finally, the measurement of prestress losses for the month following prestress application revealed minimal progressive losses, with only 250 and 100 με recorded for the axial and hoop strains, respectively.
  • Item
    Contrast enhancement by multi-level histogram shape segmentation with adaptive detail enhancement for noise suppression
    (Elsevier, 2018-11-12) Tohl, Damian; Li, Jimmy Siu
    The usual problems associated with image enhancement include over- and under-enhancement, halo effects at edges and the degradation of the signal-to-noise ratio as the enhancement of details increases. Some of those problems manifest in the background and some in the details of the enhanced image. Our proposed method is to apply different techniques to enhance the background and details separately. For enhancement of the image background, a novel multi-level histogram shape segmentation method which will detect abrupt changes in the histogram is proposed so that regions of intensity values with a similar frequency of occurrence are segmented for individual equalization to avoid over-enhancement. For detail enhancement, a novel adaptive median based enhancement method is applied to the details to avoid over- and under-enhancement while suppressing noise by limiting the degree of enhancement in homogeneous regions. Halo effects due to the over-enhancement of edges are avoided in our proposed method by using an edge preserving filter for the separation of the background and details so that edges are excluded from detail enhancement. It has been shown that our proposed method is able to avoid the usual adverse problems of image enhancement while producing adequate overall enhancement.
  • Item
    Understanding interfacial interactions of polydopamine and glass fiber and their enhancement mechanisms in epoxy-based laminates
    (Elsevier, 2018-10-17) Zhang, Hong-ping; Han, Wei; Tavakoli, Javad; Zhang, Ya-ping; Lin, Xiaoyan; Lu, Xiong; Ma, Yong; Tang, Youhong
    Interfacial behavior greatly affects the bulk mechanical performance of fiber reinforced polymer laminates. In this study, polydopamine modified glass fiber was used to fabricate short glass fiber reinforced polymer (GFRP) laminates. The interactions between glass fiber and polydopamine were studied experimentally and theoretically by X-ray photoelectron spectroscopy (XPS) and density functional calculation respectively. Theoretical study clearly demonstrated that electronic interactions existed between polydopamine and glass fiber, indicating the hydrogen bonds/chemical interactions between them that were also demonstrated by XPS results. The enhanced interfacial interaction significantly benefited GFRP laminates, as demonstrated by various mechanical characterizations such as single fiber pull-out and Mode I interlaminar fracture toughness tests. Combining the theoretical and experimental studies indicated that polydopamine modification of glass fiber could be an easy and effective way to significantly improve the interfacial interactions between glass fiber and matrix and enhance the mechanical properties of GFRP laminates.
  • Item
    Evaluating the primary stability of standard vs lateralised cementless femoral stems – A finite element study using a diverse patient cohort
    (Elsevier, 2018-09-05) Al-Dirini, Rami M A; Martelli, Saulo; Huff, Daniel; Zhang, Ju; Clement, John G; Besier, Thor; Taylor, Mark
    Background Restoring the original femoral offset is desirable for total hip replacements as it preserves the original muscle lever arm and soft tissue tensions. This can be achieved through lateralised stems, however, the effect of variation in the hip centre offset on the primary stability remains unclear. Methods Finite element analysis was used to compare the primary stability of lateralised and standard designs for a cementless femoral stem (Corail®) across a representative cohort of male and female femora (N = 31 femora; age from 50 to 80 years old). Each femur model was implanted with three designs of the Corail® stem, each designed to achieve a different degree of lateralisation. An automated algorithm was used to select the size and position that achieve maximum metaphyseal fit for each of the designs. Joint contact and muscle forces simulating the peak forces during level gait and stair climbing were scaled to the body mass of each subject. Findings The study found that differences in restoring the native femoral offset introduce marginal differences in micromotion (differences in peak micromotion <21 μm), for most cases. Nonetheless, significant reduction in the interfacial strains (>3000 με) was achieved for some subjects when lateralized stems were used. Interpretation Findings of this study suggest that, with the appropriate size and alignment, the standard offset design is likely to be sufficient for primary stability, in most cases. Nonetheless, appropriate use of lateralised stems has the potential reduce the risk of peri-prosthetic bone damage. This highlights the importance of appropriate implant selection during the surgical planning stage.
  • Item
    A real-time interactive system of surface reconstruction and dynamic projection mapping with RGB-depth sensor and projector
    (SAGE Publications, 2018-07-01) Guo, Yundong; Chu, Shu-Chuan; Liu, Zhenyu; Qiu, Chan; Luo, Hao; Tan, Jianrong
    Reconstruction and projection mapping enable us to bring virtual worlds into real spaces, which can give spectators an immersive augmented reality experience. Based on an interactive system with RGB-depth sensor and projector, we present a combined hardware and software solution for surface reconstruction and dynamic projection mapping in real time. In this article, a novel and adaptable calibration scheme is proposed, which is used to estimate approximate models to correct and transform raw depth data. Besides, our system allows for smooth real-time performance using an optimization framework, including denoising and stabilizing. In the entire pipeline, markers are only used in the calibration procedure, and any priors are not needed. Our approach enables us to interact with the target surface in real time, while maintaining correct illumination. It is easy and fast to develop different applications for our system, and some interesting cases are demonstrated at last.
  • Item
    Time-elapsed synchrotron-light microstructural imaging of femoral neck fracture
    (Elsevier, 2018-05-22) Martelli, Saulo; Perilli, Egon
    Time-elapsed micro-computed-tomography (μCT) imaging allows studying bone micromechanics. However, no study has yet performed time-elapsed μCT imaging of human femoral neck fractures. We developed a protocol for time-elapsed synchrotron μCT imaging of the microstructure in the entire proximal femur, while inducing clinically-relevant femoral neck fractures. Three human cadaver femora (females, age: 75–80 years) were used. The specimen-specific force to be applied at each load step was based on the specimens’ strength estimated a priori using finite-element analysis of clinical CT images. A radio-transparent compressive stage was designed for loading the specimens while recording the applied load during synchrotron μCT scanning. The total μCT scanning field of view was 146 mm wide and 131 mm high, at 29.81 µm isotropic pixel size. Specimens were first scanned unloaded, then under incremental load steps, each equal to 25% of the estimated specimens’ strength, and ultimately after fracture. Fracture occurred after 4–5 time-elapsed load steps, displaying sub-capital fracturing of the femoral neck, in agreement with finite-element predictions. Time-elapsed μCT images, co-registered to those of the intact specimen, displayed the proximal femur microstructure under progressive deformation up to fracture. The images showed (1) a spatially heterogeneous deformation localized in the proximal femoral head; (2) a predominantly elastic recovery, after load removal, of the diaphyseal and trochanteric regions and; (3) post-fracture residual displacements, mainly localized in the fractured region. The time-elapsed μCT imaging protocol developed and the high resolution images generated, made publicly available, may spur further research into human femur micromechanics and fracture.
  • Item
    Online path planning for AUV rendezvous in dynamic cluttered undersea environment using evolutionary algorithms
    (Elsevier, 2017-10-24) MahmoudZadeh, Somaiyeh; Yazdani, Amirmehdi M; Sammut, Karl; Powers, David Martin
    In this study, a single autonomous underwater vehicle (AUV) aims to rendezvous with a submerged leader recovery vehicle through a cluttered and variable operating field. The rendezvous problem is transformed into a Nonlinear Optimal Control Problem (NOCP) and then numerical solutions are provided. A penalty function method is utilized to combine the boundary conditions, vehicular and environmental constraints with the performance index that is final rendezvous time. Four evolutionary based path planning methods namely Particle Swarm Optimization (PSO), Biogeography-Based Optimization (BBO), Differential Evolution (DE), and Firefly Algorithm (FA) are employed to establish a reactive planner module and provide a numerical solution for the proposed NOCP. The objective is to synthesize and analyze the performance and capability of the mentioned methods for guiding an AUV from an initial loitering point toward the rendezvous through a comprehensive simulation study. The proposed planner module entails a heuristic for refining the path considering situational awareness of environment, encompassing static and dynamic obstacles within a spatiotemporal current fields. The planner thus needs to accommodate the unforeseen changes in the operating field such as emergence of unpredicted obstacles or variability of current field and turbulent regions. The simulation results demonstrate the inherent robustness and efficiency of the proposed planner for enhancing a vehicle’s autonomy so as to enable it to reach the desired rendezvous. The advantages and shortcoming of all utilized methods are also presented based on the obtained results.
  • Item
    Neurocranial anatomy of an enigmatic Early Devonian fish sheds light on early osteichthyan evolution
    (eLife Sciences Publications, 2018-05-29) Clement, Alice M; King, Benedict; Giles, Sam; Choo, Brian; Ahlberg, Per E; Young, Gavin C; Long, John A
    The skull of ‘Ligulalepis’ from the Early Devonian of Australia (AM-F101607) has significantly expanded our knowledge of early osteichthyan anatomy, but its phylogenetic position has remained uncertain. We herein describe a second skull of ‘Ligulalepis’ and present micro-CT data on both specimens to reveal novel anatomical features, including cranial endocasts. Several features previously considered to link ‘Ligulalepis’ with actinopterygians are now considered generalized osteichthyan characters or of uncertain polarity. The presence of a lateral cranial canal is shown to be variable in its development between specimens. Other notable new features include the presence of a pineal foramen, the some detail of skull roof sutures, the shape of the nasal capsules, a placoderm-like hypophysial vein, and a chondrichthyan-like labyrinth system. New phylogenetic analyses place ‘Ligulalepis’ as a stem osteichthyan, specifically as the sister taxon to ‘psarolepids’ plus crown osteichthyans. The precise position of ‘psarolepids’ differs between parsimony and Bayesian analyses.