Computed Tomography Research Papers - Academia.edu (original) (raw)

Computed Tomography Scanner (CT Scan) is one of the largest medical imaging technology discovery in the field of medical radiology. With the CT scan, an image of the inside of the human body tomography or transverse incision can be... more

Computed Tomography Scanner (CT Scan) is one of the largest medical imaging technology discovery in the field of medical radiology. With the CT scan, an image of the inside of the human body tomography or transverse incision can be displayed, where the different density of each tissue is expressed in a scale from black to white (gray scale) based on attenuation values of each organ to X-ray radiation. CT technology development direction in the current issue are preferred to increase the speed of multi-slice imaging detector, image resolution enhancement, and reduction of the radiation dose received by the patient. The highest speed attained by DSCT technology that will directly correlate with patient dose reduction and the best resolution achieved with multi-slice detector technology combined with the focus moves to the X-ray tube.

Early Archaic human skeletal remains found in a burial context in Lapa do Santo in east-central Brazil provide a rare glimpse into the lives of hunter-gatherer communities in South America, including their rituals for dealing with the... more

Early Archaic human skeletal remains found in a burial context in Lapa do Santo in east-central Brazil provide a rare glimpse into the lives of hunter-gatherer communities in South America, including their rituals for dealing with the dead. These included the reduction of the body by means of mutilation, defleshing, tooth removal, exposure to fire and possibly cannibalism, followed by the secondary burial of the remains according to strict rules. In a later period, pits were filled with disarticulated bones of a single individual without signs of body manipulation, demonstrating that the region was inhabited by dynamic groups in constant transformation over a period of centuries.

An unparalleled group of casting moulds is housed at the Egyptian Museum of Bonn University (Germany). They were discovered in 1969 by Bonn Egyptologists under Elmar Edel in rock-cut tomb Qubbet el-Hawa (QH) 207. This tomb, dating back to... more

An unparalleled group of casting moulds is housed at the Egyptian Museum of Bonn University (Germany). They were discovered in 1969 by Bonn Egyptologists under Elmar Edel in rock-cut tomb Qubbet el-Hawa (QH) 207. This tomb, dating back to the end of the Old Kingdom, was reused by members of the local Elephantine priesthood in the Late Period. The casting workshop materials were found in the context of the youngest Late Period burial. Their specific location has, however, not been recorded in detail. Nevertheless, they enable both Egyptologists and natural scientists to fully study the technology of solid bronze casting of the Late Period for the first time, using a wide range of modern meth- ods of analysis. The artefacts portray the entire casting procedure, starting with the preparation of wax models to the finished god’s bronze. In particular, they shed new light on the technology as well as the material composition of the casting moulds, which were virtually unknown up to now. The paper highlights the potential of these modern scientific approaches and the significance of this artefact group for the understanding of ancient Egyptian casting technology.

In-situ micro X-ray Computed Tomography (XCT) tests of concrete cubes under progressive compressive loading were carried out to study 3D fracture evolution. Both direct segmentation of the tomography and digital volume correlation (DVC)... more

In-situ micro X-ray Computed Tomography (XCT) tests of concrete cubes under progressive compressive loading were carried out to study 3D fracture evolution. Both direct segmentation of the tomography and digital volume correlation (DVC) mapping of the displacement field were used to characterise the fracture evolution. Realistic XCT-image based finite element (FE) models under periodic boundaries were built for asymptotic homogenisation of elastic properties of the concrete cube with Young's moduli of cement and aggregates measured by micro-indentation tests. It is found that the elastic moduli obtained from the DVC analysis and the FE homogenisation are comparable and both within the Reuss-Voigt theoretical bounds, and these advanced techniques (in-situ XCT, DVC, micro-indentation and image-based simulations) offer highly-accurate, complementary functionalities for both qualitative understanding of complex 3D damage and fracture evolution and quantitative evaluation of key material properties of concrete.

Cruziana, Gordia, Planolites, Rusophycus, and Trichophycus are common ichnological elements of the Kaili Biota. New discoveries based on the examination of 323 specimens include eldoniids, echinoderms, trilobites, monoplacophorans, and... more

Cruziana, Gordia, Planolites, Rusophycus, and Trichophycus are common ichnological elements of the Kaili Biota. New discoveries based on the examination of 323 specimens include eldoniids, echinoderms, trilobites, monoplacophorans, and non-biomineralizing arthropods that are associated with trace fossils. Based on the observed effects of bioturbation on the preservation of five different animal groups, it is clear that infaunal scavengers/deposit feeders were periodically active on the Kaili sea floor and were able to reach historic layers yielding exceptionally preserved fossils. In general, the average level of infaunal activity is absent to moderate (Ichnofabric Index [i.i.] = 1 to 3) in the Kaili substrate; by contrast, the “Phycodes beds” are completely disturbed by infaunal activity (i.i. = 5). Observed burrow diameter ranges from diminutive (∼ 0.2 mm) to normal (up to 4.2 mm). Computed tomography allows us to visualize the precise geometry of the trace fossil–body fossil association in three dimensions. We concluded that although some Kaili infaunal animals could bore through the biomineralized echinoderms, they did not appear to have scavenged upon these echinoderms based on our three-dimensional reconstruction. Furthermore, Kaili burrowers can reach the historic layers containing exceptionally preserved fossils without altering soft-tissue preservation. On the other hand, we used conventional techniques to reveal that one burrow is filled with fecal pellets (100–200 μm) at its terminal end. Because most burrows are filled with yellow/brown “coarse sediment”, and because there is no compositional difference between the fecal pellets and the surrounding coarse sediment within the burrow, the origin of the yellow/brown “coarse sediment” is interpreted here as parautochthonous and/or autochthonous and as a result of sediment reworking by deposit (or suspension) feeders. The relative scarcity of soft-part preservation in the Kaili Biota compared to the older Chengjiang Biota and the younger Burgess Shale Biota may be the result of post-burial bio-disturbance due to the relatively high intensity of local bioturbation. It is plausible that oxygenation in deeper sediments (facilitated by bioturbation) allowed carcasses in the Kaili biota to undergo a more extensive period of ‘normal’ decay prior to final burial than in other Cambrian Konservat-Lagerstätten.

The bow and arrow is thought to be a unique development of our species, signalling higher-level cognitive functioning. How this technology originated and how we identify archaeological evidence for it are subjects of ongoing debate.... more

The bow and arrow is thought to be a unique development of our species, signalling higher-level cognitive functioning. How this technology originated and how we identify archaeological evidence for it are subjects of ongoing debate. Recent analysis of the putative bone arrow point from Sibudu Cave in South Africa, dated to 61.7±1.5kya, has provided important new insights. High-resolution CT scanning revealed heat and impact damage in both the Sibudu point and in experimentally produced arrow points. These features suggest that the Sibudu point was first used as an arrowhead for hunting, and afterwards was deposited in a hearth. Our results support the claim that bone weapon tips were used in South African hunting long before the Eurasian Upper Palaeolithic.

The aim of this study is to describe the steps needed for producing medical models by 3D printing. Further, the timeline for various 3D printing processes and related process steps and their estimated cost structure will be discussed.... more

The aim of this study is to describe the steps needed for producing medical models by 3D printing. Further, the timeline for various 3D printing processes and related process steps and their estimated cost structure will be discussed. Computed tomography images were used as a starting point for the present case and a 3D model of skull and jaw was reconstructed using Osirix software. 3D printing with material extrusion, binder jetting and material jetting processes with pre-and post-processing were explored and a model for the costs and timeline were formed. The results of this study show that, (1) binder jetting clearly is the fastest technique to produce medical models. The total process time varied from 2 h 51 min to 10 h 28 min for the jaw model and from 10 h 24 min to 66 h 13 min for the skull model. Regarding costs, (2) material extrusion is a little more affordable to produce a jaw model followed by binder jetting. To produce a skull model, binder jetting seems more affordable than material extrusion or material jetting. Material jetting is much more expensive than the two other techniques but it is also much more accurate based on the published Le Courrier de la Transplantation-Vol. 18-n 1-2-june 2018 reports. In binder and material jetting adding more parts in the same 3D printing instance will reduce the cost remarkably.

Computer-aided visualization and analysis of fossils has revolutionized the study of extinct organisms. Novel techniques allow fossils to be characterized in three dimensions and in unprecedented detail. This has enabled... more

Computer-aided visualization and analysis of fossils has
revolutionized the study of extinct organisms. Novel
techniques allow fossils to be characterized in three
dimensions and in unprecedented detail. This has enabled
paleontologists to gain important insights into
their anatomy, development, and preservation. New
protocols allow more objective reconstructions of fossil
organisms, including soft tissues, from incomplete
remains. The resulting digital reconstructions can be
used in functional analyses, rigorously testing longstanding
hypotheses regarding the paleobiology of extinct
organisms. These approaches are transforming our
understanding of long-studied fossil groups, and of the
narratives of organismal and ecological evolution that
have been built upon them.

Advances in image acquisition and processing, including the increasing availability of computed tomography (CT), have expanded the research potential for radiography. This paper employs recent radiographic advancements to investigate how... more

Advances in image acquisition and processing, including the increasing availability of computed tomography (CT), have expanded the research potential for radiography. This paper employs recent radiographic advancements to investigate how hand-formed pottery was manufactured, with a focus on defining " micro-techniques " that may be isomorphic with past social groups. By creating and imaging experimental vessels, unique structural " fingerprints " are defined for a number of micro-techniques, which are then used to categorize assemblages from two contemporaneous and neighboring archaeological sites. Results suggest that the two sites were occupied by distinct potting communities and that radiographic imaging can be a powerful tool for determining the presence of past social groups.

Proprioceptive training has been shown to reduce the incidence of ankle sprains in different sports. It can also improve rehabilitation after anterior cruciate ligament (ACL) injuries whether treated operatively or nonoperatively. Since... more

Proprioceptive training has been shown to reduce the incidence of ankle sprains in different sports. It can also improve rehabilitation after anterior cruciate ligament (ACL) injuries whether treated operatively or nonoperatively. Since ACL injuries lead to long absence from sports and are one of the main causes of permanent sports disability, it is essential to try to prevent them. In a prospective controlled study of 600 soccer players in 40 semiprofessional or amateur teams, we studied the possible preventive effect of a gradually increasing proprioceptive training on four different types of wobble-boards during three soccer seasons. Three hundred players were instructed to train 20 min per day with 5 different phases of increasing difficulty. The first phase consisted of balance training without any balance board; phase 2 of training on a rectangular balance board; phase 3 of training on a round board; phase 4 of training on a combined round and rectangular board; phase 5 of training on a so-called BABS board. A control group of 300 players from other, comparable teams trained “normally” and received no special balance training. Both groups were observed for three whole soccer seasons, and possible ACL lesions were diagnosed by clinical examination, KT-1000 measurements, magnetic resonance imaging or computed tomography, and arthroscopy. We found an incidence of 1.15 ACL injuries per team per year in the control group and 0.15 injuries per team per year in the proprioceptively trained group (P

A retrospective radiographic study was performed to investigate the prevalence of diffuse idiopathic skeletal hyperostosis (DISH) and spondylosis deformans (spondylosis) in 2041 purebred dogs and to determine association with age, gender... more

A retrospective radiographic study was performed to investigate the prevalence of diffuse idiopathic skeletal hyperostosis (DISH) and spondylosis deformans (spondylosis) in 2041 purebred dogs and to determine association with age, gender and breed. Four cases of DISH provided information on the appearance of canine DISH.The prevalence of DISH and spondylosis was 3.8% (78/2041) and 18.0% (367/2041), respectively. Of dogs with

The site of Pantalla (central Italy) yielded a rich late Villafranchian (Early Pleistocene) faunal assemblage, which includes some well-preserved large mammal skulls. We describe here two nearly complete crania and a left hemimandible of... more

The site of Pantalla (central Italy) yielded a rich late Villafranchian (Early Pleistocene) faunal assemblage, which includes some well-preserved large mammal skulls. We describe here two nearly complete crania and a left hemimandible of Acinonyx pardinensis from this locality, representing the most complete cranial material of this species in Europe. These finds allowed us to define more clearly the craniodental morphology of A. pardinensis. Similarly to the forms from North Africa and China, the giant cheetah from Pantalla has a more generalized skull than the living Acinonyx jubatus, showing some primitive, pantherine-like features such as the less domed dorsal outline of the cranium, the more developed sagittal and nuchal crests and the less bowed zygomatic arches. High-resolution CT scans of the specimens were used to obtain the first 3D model of a cranium with articulated mandible of A. pardinensis. Starting from the insertion areas on this model we reconstructed the jaw muscles of the Pantalla felid, confirming its affinities with pantherine felines. In the light of the musculoskeletal skull anatomy and the average body mass (about 80 kg), it is likely that A. pardinensis could kill large prey through a hunting strategy more similar to pantherine cats than to the living cheetah.

A number of studies have demonstrated that bone scintigraphy has high sensitivity and efficacy in the early detection of bone metastases from several tumours, including breast cancer. Bone scintigraphy is the most definitive tool for... more

A number of studies have demonstrated that bone scintigraphy has high sensitivity and efficacy in the early detection of bone metastases from several tumours, including breast cancer. Bone scintigraphy is the most definitive tool for diagnosing and monitoring metastatic spread of breast cancer. However, in the past decade there has been a wide debate on its impact on survival time, morbidity and quality of life. Worldwide economic restrictions and these studies have led to the adoption of an almost minimalist policy for breast cancer follow-up using evidence-based guidelines. The recommended breast cancer surveillance testing includes only a few procedures (history, physical and breast self-examination, patient education on symptoms, pelvic examination). The routine use of additional tests, such as blood cell count, tumour markers, liver ultrasonography, bone scan and chest X-rays, is not recommended. Accordingly, scintigraphy should be reserved for a limited number of patients. On ...

The aim of this study is to describe the steps needed for producing medical models by 3D printing. Further, the timeline for various 3D printing processes and related process steps and their estimated cost structure will be discussed.... more

The aim of this study is to describe the steps needed for producing medical models by 3D printing. Further, the timeline for various 3D printing processes and related process steps and their estimated cost structure will be discussed. Computed tomography images were used as a starting point for the present case and a 3D model of skull and jaw was reconstructed using Osirix software. 3D printing with material extrusion, binder jetting and material jetting processes with pre-and post-processing were explored and a model for the costs and timeline were formed. The results of this study show that, (1) binder jetting clearly is the fastest technique to produce medical models. The total process time varied from 2 h 51 min to 10 h 28 min for the jaw model and from 10 h 24 min to 66 h 13 min for the skull model. Regarding costs, (2) material extrusion is a little more affordable to produce a jaw model followed by binder jetting. To produce a skull model, binder jetting seems more affordable than material extrusion or material jetting. Material jetting is much more expensive than the two other techniques but it is also much more accurate based on the published reports. In binder and material jetting adding more parts in the same 3D printing instance will reduce the cost remarkably.

Over the last forty years or so, central Mali and, more specifically, the Inland Niger Delta, have supplied the Western art market with hundreds of terracotta figures obtained through clandestine excavations. These so-called Djenne... more

Over the last forty years or so, central Mali and, more specifically, the Inland Niger Delta, have supplied the Western art market with hundreds of terracotta figures obtained through clandestine excavations. These so-called Djenne archaeological objects, most of which are figurative and date from the thirteenth to the seventeenth century, are now in museum and private collections. The lack of scientific data about their original context has led to considerable guesswork about just what they represent. To remedy this deficiency, we have called on Mande oral tradition that preserves the knowledge of the region as well as upon medical imaging to attempt an interpretation of some of these artworks

South African museums house a small, but still important collection of material from ancient Egypt, including animal mummies. The study of ancient Egyptian animal mummies is varied and extensive and it is important to determine what... more

South African museums house a small, but still important collection of material from ancient Egypt, including animal mummies. The study of
ancient Egyptian animal mummies is varied and extensive and it is important to determine what animals were used, the mummification process and why they were mummified. New methodologies and modern technologies are becoming more readily available for research and are beingused to unlock the secrets of animal mummies without causing any damage to these artefacts. Recently, seven animal mummies housed in the collections of Iziko Museums of South Africa in Cape Town and Ditsong: National Museum of Cultural History in Pretoria were scanned using a state of the art computed tomography (CT) scanner at Stellenbosch University. These scans provide a digital 3D rendering of the artefact which can be reproduced via a 3D printer. The results of this non-invasive method revealed four complete bird skeletons, a claw, a fake and the partial skeleton of a cat. These animals are thought to be votive mummies.

The application of X-radiography in ceramic studies is becoming an increasingly valued method. Using the potential of industrial X-ray computed tomography (CT) for non-destructive testing as an archaeometric or archaeological method in... more

The application of X-radiography in ceramic studies is becoming an increasingly valued method. Using the potential of industrial X-ray computed tomography (CT) for non-destructive testing as an archaeometric or archaeological method in pottery studies, especially regarding aspects such as manufacturing techniques or pottery fabrics, requires controlled data-acquisition and post-processing by scientific computing adjusted to archaeological issues. The first results of this evaluation project show that, despite the difficulties inherent in CT technology, considerable information can be extracted for pottery analysis. The application of surface morphology reconstructions and volumetric measurements based on CT data will open a new field in future non-invasive archaeology.

Full field mapping of displacements between successive images by digital image correlation is a powerful and well-established technique, used in fields as diverse as geo-tectonics, engineering mechanics and materials science. Analysis of... more

Full field mapping of displacements between successive images by digital image correlation is a powerful and well-established technique, used in fields as diverse as geo-tectonics, engineering mechanics and materials science. Analysis of three-dimensional images, such as computed X-ray tomographs, is also becoming routine. These techniques provide new ways to study and quantify deformation and failure processes: recently they have been applied to detect and study cracks and defects in engineering materials, for instance by coupling the displacement analysis with finite element codes to readily extract the crack propagation strain energy release rate (J Integral). Such analyses increase the richness of the data obtained, for example providing information on the mode of loading, and are suitable for the analysis of engineering components under complex states of stress.
This work has highlighted areas where the development of image correlation methods that are optimised for analysis of discontinuities would be beneficial, for better detection of small cracks and the early development of damage against the background displacement field; improved precision in crack displacement field measurement by intelligent “masking’ or analysis algorithms and better integration with finite element software packages to make use of advanced tools for 2D and 3D deformation analysis.
This paper reviews some of this recent work on the analysis of 2D and 3D damage in engineering materials, and describes developments in quantitative analysis of defects by image correlation. The examples covered include brittle crack propagation in nuclear graphite, fatigue loading in magnesium alloys and indentation damage in brittle and ductile materials.

Volumetric modulated arc therapy (VMAT) is a novel form of intensity-modulated radiotherapy (IMRT) optimization that allows the radiation dose to be delivered in a single gantry rotation of up to 360°, using either a constant dose rate... more

Volumetric modulated arc therapy (VMAT) is a novel form of intensity-modulated radiotherapy (IMRT) optimization that allows the radiation dose to be delivered in a single gantry rotation of up to 360°, using either a constant dose rate (cdr-VMAT) or variable dose rate (vdr-VMAT) during rotation. The goal of this study was to compare VMAT prostate RT plans with three-dimensional conformal RT (3D-CRT) and IMRT plans.The 3D-CRT, five-field IMRT, cdr-VMAT, and vdr-VMAT RT plans were created for 10 computed tomography data sets from patients undergoing RT for prostate cancer. The parameters evaluated included the doses to organs at risk, equivalent uniform doses, dose homogeneity and conformality, and monitor units required for delivery of a 2-Gy fraction.The IMRT and both VMAT techniques resulted in lower doses to normal critical structures than 3D-CRT plans for nearly all dosimetric endpoints analyzed. The lowest doses to organs at risk and most favorable equivalent uniform doses were achieved with vdr-VMAT, which was significantly better than IMRT for the rectal and femoral head dosimetric endpoints (p < 0.05) and significantly better than cdr-VMAT for most bladder and rectal endpoints (p < 0.05). The vdr-VMAT and cdr-VMAT plans required fewer monitor units than did the IMRT plans (relative reduction of 42% and 38%, respectively; p = 0.005) but more than for the 3D-CRT plans (p = 0.005).The IMRT and VMAT techniques achieved highly conformal treatment plans. The vdr-VMAT technique resulted in more favorable dose distributions than the IMRT or cdr-VMAT techniques, and reduced the monitor units required compared with IMRT.

A study of cerebral hemorrhage detection using computed tomography with head image has been done. The process after detection is the determination of the area and volume of hemorrhage. Image processing techniques used are Segmentation of... more

A study of cerebral hemorrhage detection using computed tomography with head image has been done. The process after detection is the determination of the area and volume of hemorrhage. Image processing techniques used are Segmentation of Otsu method. This segmentation method successfully obtained binary image and proceed with morphology process, with output image result of morphology operaionis calculated the area. After the area of the object on each image slice is obtained, the next step is the volume calculation. Volume calculation is done by summing the area of the object on each slice then the result multiplied by the slice thickness. The result of the use of image processing techniques can be offered as a substitute for manual calculating by doctors. Keywords— Cerebral hemorrhage, segmentation of otsu method, computed tomography, area and volume.

Forensic anthropologists are routinely asked to estimate a biological profile (i.e., age, sex, ancestry and stature) from a set of unidentified remains. In contrast to the abundance of collections and techniques associated with adult... more

Forensic anthropologists are routinely asked to estimate a biological profile (i.e., age, sex, ancestry and stature) from a set of unidentified remains. In contrast to the abundance of collections and techniques associated with adult skeletons, there is a paucity of modern, documented subadult skeletal material, which limits the creation and validation of appropriate forensic standards. Many are forced to use antiquated methods derived from small sample sizes, which given documented secular changes in the growth and development of children, are not appropriate for application in the medico-legal setting. Therefore, the aim of this project is to use multi-slice computed tomography (MSCT) data from a large, diverse sample of modern subadults to develop new methods to estimate subadult age and sex for practical forensic applications. The research sample will consist of over 1,500 full-body MSCT scans of modern subadult individuals (aged birth to 20 years) obtained from two U.S. medical examiner's offices. Statistical analysis of epiphyseal union scores, long bone osteometrics, and os coxae landmark data will be used to develop modern subadult age and sex estimation standards. This project will result in a database of information gathered from the MSCT scans, as well as the creation of modern, statistically rigorous standards for skeletal age and sex estimation in subadults. Furthermore, the research and methods developed in this project will be applicable to dry bone specimens, MSCT scans, and radiographic images, thus providing both tools and continued access to data for forensic practitioners in a variety of settings.

In bibliografia l'attività di microscavo raramente viene affrontata dal punto di vista metodologico, ma diviene spesso funzionale, solo come mezzo, alla messa in luce di un manufatto di particolare rilievo o complessità. L'intervento qui... more

In bibliografia l'attività di microscavo raramente viene affrontata dal punto di vista metodologico, ma diviene spesso funzionale, solo come mezzo, alla messa in luce di un manufatto di particolare rilievo o complessità. L'intervento qui esposto si propone, attraverso l'esperienza di studio svolta su tre blocchi di terra contenti reperti metallici, provenienti da una tomba etrusca datata al periodo Orientalizzante, di individuare e descrivere una metodologia univoca applicabile a stacchi contenenti oggetti o frammenti anche di materiali diversi. Attraverso l'analisi di casi noti in letteratura si è cercato di mettere appunto una metodologia che impiegasse in maniera ottimale i dati ottenuti delle indagini analitiche preliminari, quali la tomografia computerizzata multistrato e la radiografia X, come anche la documentazione fotografica prodotta durante tutta la fase di lavoro. L'impiego di questi dati uniti all'individuazione di alcuni aspetti chiave relativi all'attività pratica di scavo, ha permesso di mettere appunto una prassi operativa da applicare univocamente ai tre casi studio. Sviluppi futuri di questo lavoro saranno legati all'applicazione della metodologia proposta su altri casi in maniera da ulteriormente valutarne limiti e implementarne i punti di forza.

Spiders are an important animal group, with a long history. Details of their origins remain limited, with little knowledge of their stem group, and no insights into the sequence of character acquisition during spider evolution. We... more

Spiders are an important animal group, with a long history. Details of their origins remain limited, with little knowledge of their stem group, and no insights into the sequence of character acquisition during spider evolution. We describe a new fossil arachnid, Idmonarachne brasieri gen. et sp. nov. from the Late Carboniferous (Stephanian, ca 305–299 Ma) of Montceau-les-Mines, France. It is three-dimensionally preserved within a siderite concretion, allowing both laboratory-and synchrotron-based phase-contrast computed tomography reconstruction. The latter is a first for siderite-hosted fossils and has allowed us to investigate fine anatomical details. Although distinctly spider-like in habitus, this remarkable fossil lacks a key diagnostic character of Araneae: spinnerets on the underside of the opisthosoma. It also lacks a flagelliform telson found in the recently recognized, spider-related, Devonian–Permian Uraraneida. Cladistic analysis resolves our new fossil as sister group to the spiders: the spider stem-group comprises the uraraneids and I. brasieri. While we are unable to demonstrate the presence of spigots in this fossil, the recovered phylogeny suggests the earliest character to evolve on the spider stem-group is the secretion of silk. This would have been followed by the loss of a flagelliform telson, and then the ability to spin silk using spinnerets. This last innovation defines the true spiders, significantly postdates the origins of silk, and may be a key to the group's success. The Montceau-les-Mines locality has previously yielded a mesothele spider (with spinnerets). Evidently, Late Palaeozoic spiders lived alongside Palaeozoic arachnid grades which approached the spider condition, but did not express the full suite of crown-group autapomorphies.