3D visualization of bioerosion in archaeological bone

Archeologia e calcolatori, 2021

Traditional radiology and, after 1975, computed tomography have been used in archaeology since their inception as non-invasive imaging techniques for dealing with delicate and valuable artefacts (e.g. mummies, Palaeolithic and ancient remains, papyrus scrolls, wood, metal tools, coins, jewellery, weapons, ceramics, wall paintings, etc.). It was not until the 21st century that microcomputed tomography (µCT) was gradually established as the desired non-invasive technique and method in archaeology. Its use and development are focused on the technological adaptation of industrial µCT recorders to archaeological and archaeometric treatment, as well as non-invasive archaeological analysis of small objects, which could be partially or permanently destroyed or damaged. To date, research attention has not been focused on the development of specific algorithms adapted to field or labo-ratory archaeological work.

2021

Recent advances have broadened the application of palaeoradiology for non-destructive investigation of ancient remains. X-ray microtomography (microCT) in particular is increasingly used as an alternative to histological bone sections for interpreting pathological alterations, trauma, microstructure, and more recently bioerosion with direct or ancillary use of histological indices. However, no systematic attempt has been made to confirm the reliability of microCT for histotaphonomic analysis of archaeological bone. The objectives of this study are therefore to (1) compare thin sections of human femora rated with the Oxford Histological Index to microCT sections using a newly developed Virtual Histological Index, and (2) provide an accessible methodology for the evaluation and visualization of bioerosion in archaeological bone using virtual anthropology techniques. We provide detailed descriptions of virtual sections and volume renderings, and also assess the efficacy of the method o...

Digital imaging allows to collect and process morphometric quantitative data on archaeological finds. The Research Unit of Prehistory and Anthropology of the University of Siena is currently developing new protocols for the analysis of bone modifications using a Hirox Digital Microscope KH-7700. This instrument captures 3D images of the observed surfaces enabling the direct observation of butchering marks, artistic engravings and non-anthropic evidences (for instance tooth marks) from several points of view; it also allows a rapid procurement of several quantitative data (linear and angular measurements) that can be processed through univariate and multivariate statistics. After the analysis of more than four hundred specimens, we are presenting in this paper the results of several case-studies from Italian Palaeolithic and Metal Age sites: we demonstrated that processing quantitative data it is possible to separate between butchering marks inflicted using stone and metal tools; to identify the kind of stone tool used to produce prehistoric artistic engravings; to separate between butchering marks and artistic engravings. All data coming from the analysis of archaeological specimens are compared with those obtained carrying out experimental proofs; it allows to corroborate our results. The encouraging obtained outcome confirms the validity of our protocols and the important role that computer applications and quantitative methods play for understanding prehistory.

2016

The Research Unit of Prehistoric Ecology of the University of Siena is testing the potentiality of a digital microscope that captures 3D images of the bone surface. The aim of this research is to develop new methods for understanding the origin of different bone modifications (e.g. scores, punctures, cut marks, chemical corrosion) using morphometry. It allows to find diagnostic criteria that can be processed through statistics, avoiding the exclusive use of subjective observations. In this paper different bone modifications have been analysed: cut marks produced during butchery experiments, modern tooth marks and striae located on macromammal remains coming from two Palaeolithic sites: Grotta dei Santi (Grosseto) and Grotta Paglicci (Foggia). The aim is to compare bone modifications of different origin and to test the method on archaeological samples, in order to understand how this can be employed to better interpret the taphonomic evidences in future works. Riassunto-L'Unità d...

This study uses a combination of digital microscopic analysis and experimental archaeology to assess stone tool cut marks on animal bones. We used two un-retouched flint flakes and two burins to inflict cut marks on fresh, boiled, and dry ungulate bones. The experiment produced three series of three engravings on each bone with each of the experimental tools. The first series involved one single stroke; the second, two strokes in the same direction; and the third, multiple strokes using a to-and-fro movement. We analyzed the striations using a Hirox 3D digital microscope (KH-7700) and collected metric and profile data on the morphology of the cut marks. In order to describe the shape of each cross section, we calculated the ratio between the breadth at the top and the breadth at the floor of cut marks. Preliminary results show that both the tool type and the method of creating the cut mark influence the shape of the resulting groove. In our experiment, morphological parameters can be used to differentiate between marks produced using un-retouched flint flakes and those produced using burins. However, neither morphological nor morphometric analysis allows us to identify the mechanical motion used to produce the cuts, nor the state of the bone (fresh, boiled, or dry) at the moment of marking.

Palaeontologia Electronica, 2012

This paper provides a brief but comprehensive guide to creating, preparing and dissecting a 'virtual' fossil, using a worked example to demonstrate some standard data processing techniques. Computed tomography (CT) is a 3D imaging modality for producing 'virtual' models of an object on a computer. In the last decade, CT technology has greatly improved, allowing bigger and denser objects to be scanned increasingly rapidly. The technique has now reached a stage where systems can facilitate large-scale, non-destructive comparative studies of extinct fossils and their living relatives. Consequently the main limiting factor in CT-based analyses is no longer scanning, but the hurdles of data processing (see disclaimer). The latter comprises the techniques required to convert a 3D CT volume (stack of digital slices) into a virtual image of the fossil that can be prepared (separated) from the matrix and 'dissected' into its anatomical parts. This technique can be applied to specimens or part of specimens embedded in the rock matrix that until now have been otherwise impossible to visualise. This paper presents a suggested workflow explaining the steps required, using as example a fossil tooth of Sphenacanthus hybodoides (Egerton), a shark from the Late Carboniferous of England. The original NHMUK copyrighted CT slice stack can be downloaded for practice of the described techniques, which include segmentation, rendering, movie animation, stereo-anaglyphy, data storage and dissemination. Fragile, rare specimens and type materials in university and museum collections can therefore be virtually processed for a variety of purposes, including virtual loans, website illustrations, publications and digital collections. Micro-CT and other 3D imaging techniques are increasingly utilized to facilitate data sharing among scientists and on education and outreach projects. Hence there is the potential to usher in a new era of global scientific collaboration and public communication using specimens in museum collections.

The exploitation of the original human fossil record is limited by its characteristics of uniqueness, fragility, and dispersal. Notably, its handling for direct observation, invasive analysis, reproduction, casting, and displayis risky. At the same time, advances in developmental and quantitative morphology reveal that a critical amount of information is hidden within the inner structure of the mineralized bony (cortical and trabecular) and dental tissues (enamel, dentine, cementum). In response to the conflicting requirements of safeguard vs. exploitation of this record, a new generation of non-invasive analytical tools -including microtomography -grant access to a wide range of previously inaccessible morpho-structural information. This recent technological "transition" in paleoanthropology implies the 3D (vs. traditional 2D) imaging and the surface/volumetric (vs. linear) assessment of the endostructural variation. Here we use the NESPOS database to illustrate the potential value of the high-resolution virtual exploration and quantitative characterization of the human fossil record.

Open Archaeology

The reconstruction of past mortuary rituals and practices increasingly incorporates analysis of the taphonomic history of the grave and buried body, using the framework provided by archaeothanatology. Archaeothanatological analysis relies on interpretation of the three-dimensional (3D) relationship of bones within the grave and traditionally depends on elaborate written descriptions and two-dimensional (2D) images of the remains during excavation to capture this spatial information. With the rapid development of inexpensive 3D tools, digital replicas (3D models) are now commonly available to preserve 3D information on human burials during excavation. A procedure developed using a test case to enhance archaeothanatological analysis and improve post-excavation analysis of human burials is described. Beyond preservation of static spatial information, 3D visualization techniques can be used in archaeothanatology to reconstruct the spatial displacement of bones over time, from deposition...

2016

Summary - The Research Unit of Prehistoric Ecology of the University of Siena is testing the potentiality of a digital microscope that captures 3D images of the bone surface. The aim of this research is to develop new methods for understanding the origin of different bone modifications (e.g. scores, punctures, cut marks, chemical corrosion) using morphometry. It allows to find diagnostic criteria that can be processed through statistics, avoiding the exclusive use of subjective observations. In this paper different bone modifications have been analysed: cut marks produced during butchery experiments, modern tooth marks and striae located on macromammal remains coming from two Palaeolithic sites: Grotta dei Santi (GR) and Grotta Paglicci (FG). The aim is to compare bone modifications of different origin and to test the method on archaeological samples, in order to understand how this can be employed to better interpret the taphonomic evidences in future works. Riassunto - La microsco...

State of the art in paleoanthropological and paleoprimatological research foresees the use of advanced non-destructive investigative approaches. Microcomputed tomography (microCT) is a fundamental tool, since it offers the opportunity to get high quality morphological information with high spatial resolution. We carried out the set-up of an experimental microCT system able to examine paleobiological samples. The equipment can operate on small objects (size up to 3 cm) with a nominal spatial resolution of 30 lm, allowing their 3D volume reconstruction and morphometric analysis. This approach represents a forefront technique in paleobiological studies, successfully employed only in a limited number of advanced research centers. A specific program of microCT analysis has been planned on a sample of human and non-human fossil primate dentitions, in order to assess the specific nature of a number of tooth lesions (e.g. caries versus abrasion). This currently in progress experimental activity represents the first step for the set-up of a research center specifically devoted to the realization of advanced studies in the field of archaeo-paleobiology.