AGMT3-D: A software for 3-D landmarks-based geometric morphometric shape analysis of archaeological artifacts

Abstract

We present here a newly developed software package named Artifact GeoMorph Toolbox 3-D (AGMT3-D). It is intended to provide archaeologists with a simple and easy-to-use tool for performing 3-D landmarks-based geometric morphometric shape analysis on 3-D digital models of archaeological artifacts. It requires no prior knowledge of programming or proficiency in statistics. AGMT3-D consists of a data-acquisition procedure for automatically positioning 3-D models in space and fitting them with grids of 3-D semi-landmarks. It also provides a number of analytical tools and procedures that allow the processing and statistical analysis of the data, including generalized Procrustes analysis, principal component analysis, a warp tool, automatic calculation of shape variabilities and statistical tests. It provides an output of quantitative, objective and reproducible results in numerical, textual and graphic formats. These can be used to answer archaeologically significant questions relating to morphologies and morphological variabilities in artifact assemblages. Following the presentation of the software and its functions, we apply it to a case study addressing the effects of different types of raw material on the morphologies and morphological variabilities present in an experimentally produced Acheulian handaxe assemblage. The results show that there are statistically significant differences between the mean shapes and shape variabilities of handaxes produced on flint and those produced on basalt. With AGMT3-D, users can analyze artifact assemblages and address questions that are deducible from the morphologies and morphological variabilities of material culture assemblages. These questions can relate to issues of, among others, relative chronology, cultural affinities, tool function and production technology. AGMT3-D is aimed at making 3-D landmarks-based geometric morphometric shape analysis more accessible to archaeologists, in the hope that this method will become a tool commonly used by archaeologists.

Innovations in Acheulean Biface Production at La Noira (Centre France): Shift or Drift Between 700 and 450 Ka in Western Europe?

“…All models are available for scienti c and academic purposes at ZENODO (35). The 3D models were processed using the AGMT3-D software (36,37). This consists of a data-acquisition procedure for automatically positioning 3D models in space and tting them with grids of 3D semi-landmarks.…”

“…A speci c morphometric analysis of handaxe symmetry in strata a and c (32) has shown that human groups mastered tool symmetry from 700 ka onwards, despite lower shaping intensity at that time. In order to continue to track the technological drift between ca 700 and ca 450 ka, we applied the WEAP method (34) on the whole corpus of handaxes of this site, combining for the rst time a technological analysis with a broader morphometric approach using AGMT3-D software (35,36).…”

Techno-functional and 3D shape analysis applied for investigating the variability of backed tools in the Late Middle Paleolithic of Central Europe

“…This approach has been developed in the last years, and successfully used in the analysis of bifacial tools in a growing number of case studies [ 62 , 98 – 100 ]. Shape statistical analysis were carried out with the software AGMT-3D, which has the advantage of performing several steps automatically [ 101 ]. Files of the objects in Wrl-format were imported into the software and at first processed for the acquisition of data: after a general alignment as described above, 3D semi-landmarks were obtained automatically with the construction of a grid formed by 50 meridians and 50 parallels, for a total of 2,500 landmarks on each surface.…”

“…In general, the morphological variability of scrapers and backed flake tools is higher than that of Keilmesser, respectively of about 12% and 18% (Table 9); this value is measured as the mean multidimensional Euclidean distance of the items in the group from the group's centroid (i.e. mean shape): the higher the value, the higher the variability [101].…”

HumanOS: an open source nomadic software database for physical anthropology and archaeology

“…The digitization of information allows a faster, more efficient and standardized recording of data that facilitates the synthesis work required by the discipline. Many database programs are developing in archaeology (Herzlinger & Grosman, 2018;LeFebvre et al, 2019) and physical anthropology, either at the initiative of personal development or collaborative (Eve & Hunt, 2008;Feugère, 2011;Gailledrat, 2016), or still institutional (Cuy et al, 2017;Meghini et al, 2017). At the same time, targeted tools are also being developed to meet specific needs: sex determination (Brŭžek et al, 2017), stature calculation (Chan, 2013), construction of stratigraphic diagrams (Desachy, 2008) or for 3D visualizations of skeletons (Kepple et al, 1998;Proko, 2014;Sachau-Carcel, 2012).…”