This thematic issue
In the field of paleobiology and paleoanthropology, the last fifteen years, or so, have witnessed some tremendous methodological and conceptual advances in the approach to the structural characterization of the mineralized tissues. This has resulted in a significant broadening of the amount and quality of the information extracted from previously poorly reported meso- and micro-anatomies. Access to such “hidden” archives has fuelled new research strategies and concepts in the assessment of the evolutionary pathways and phylogenetic relationships, adaptive strategies, developmental rates and variation patterns in past human populations and fossil hominin taxa, and is increasingly used to unveil subtle aspects of their life history, including seasonally-related individual–environment fluctuating relationships recorded during growth.
Only seven years after the discovery of X-rays by W.C. Röntgen, in 1895, D. Gorjanović-Kramberger, 1902 and Gorjanović-Kramberger, 1906 performed the radiographic-based anatomical description of several maxillary, mandibular and dental specimens from the Neanderthal assemblage of Krapina, Croatia, the very first application of such a revolutionary investigative technique to the study of fossil specimens (in Kricun et al., 1999). Such an analytical approach became routine in paleoanthropology (e.g., Skinner and Sperber, 1982) and, in the early 1980s, would be followed by another major shift in the characterization of the fossil record: the advent of Computed Tomography (CT), a technology allowing the three-dimensional (3D) rendering of hidden morphologies (among others pioneering applications, see Conroy and Vannier, 1987). Coupled with landmark-based Geometric Morphometrics (Bookstein, 1991) and Finite Element Analysis (reviewed in Rayfield, 2007) applied to CT- and 3D surface scanning-based records (Zollikofer and Ponce de León, 2005), the computer-aided visualization and analysis of fossils has quickly evolved into even sharper analytical tools allowing morphology to be quantified at an extremely fine scale: X-ray Microtomography (μCT) (Ketcham and Carlson, 2001, Mees et al., 2003 and Stock, 2009) and neutron microtomography (n-μCT) (Schwarz et al., 2005 and Tremsin et al., 2011) (for a review and some applications, see Braga, 2016, Gross et al., 2014 and Le Cabec et al., 2015).
Following the innovative application of Synchrotron Radiation Microtomography (SR-μCT) to the study of enamel in recent and fossil primate teeth (Tafforeau, 2004) and the first 2–3D virtual analyses of Miocene hominid and Pliocene hominin remains performed by industrial microtomography (Kunimatsu et al., 2004, Macchiarelli et al., 2004 and Rossi et al., 2004), the use of such tools has become essential in paleobiological and paleoanthropological research (e.g., Chirchir et al., 2015, Macchiarelli et al., 2013, Macchiarelli et al., 2006, Macchiarelli et al., 2008, Ryan and Sukhdeo, 2016, Skinner et al., 2013, Skinner et al., 2015 and Smith et al., 2010, just to cite a few). Interesting examples of such applications have been illustrated in the Palevol thematic issue Imaging & 3D in palaeontology and palaeoanthropology–3D & Imagerie en sciences paléontologiques et paléoanthropologiques, edited in 2010 by G. Clément and D. Geffard-Kuriyama.
Coupled with the integration of the third dimension in structural visualization and quantitative assessment, the analytical shift from the hard outer (the “container”) to the virtually imaged inner morphology (the “contents”) has not only added a significant amount of new information and fostered new research perspectives, but also affected our traditional research strategies and daily practices, thus requiring new concepts and implying new questions. This is exactly what this thematic issue, entitled Hominin biomechanics, virtual anatomy and inner structural morphology: From head to toe. A tribute to Laurent Puymerail, intends to illustrate.
This thematic issue collects 17 original invited articles contributed by 70 researchers from 11 countries. It is devoted to the memory of Dr. Laurent Puymerail, a brilliant, young paleoanthropologist who prematurely passed away shortly after having obtained a permanent position as a researcher in paleobiomechanics and bone biology at the French CNRS, and having been assigned to the UMR 7268 CNRS–Université d’Aix-Marseille–EFS (see his obituary in Marchal et al., 2016, where his complete bibliography can be found). Among other contributions to the field, Laurent participated in the elaboration and first applications to the fossil record of some advanced techniques for imaging and quantifying topographic thickness variation in long bone shafts and tooth roots by means of morphometric maps (Bayle et al., 2011, Bondioli et al., 2010, Puymerail, 2011, Puymerail, 2013, Puymerail et al., 2012a and Puymerail et al., 2012b). Laurent also launched the study of the inner characteristics of the Early Pleistocene African Homo erectus distal humerus from Gombore IB, at Melka Kunture, Ethiopia (Puymerail et al., 2014), and in this volume he appears among the co-authors of a contribution on the distal humerus in fossil hominins (Cazenave et al., this volume). More importantly, as Supporting Information to the present foreword, we provide the uncompleted manuscript of his ongoing study on the locomotor-related characteristics of the Orrorin's femur entitled “The structural and mechanical properties of the Orrorin tugenensis femoral shaft and the assessment of bipedalism in early hominins” (Puymerail, this volume). Based on a conceptual and methodological analytical background presented in 2013 at the 3rd Annual Meeting of the European Society for the Study of Human Evolution (Puymerail and O’Higgins, 2013; Fig. 1 and Fig. 2), this document summarizes a remarkable amount of new biomechanical information on this early member of the hominin clade.
Laurent was too young to have formal students, but his presence in the labs at the MNHN of Paris and at the Universities of Marseille and Poitiers was instructive to all us older students of palaeoanthropology. He had the rare ability to reduce complex aspects of morphology so that others could appreciate the meaning and significance through virtual imaging and statistics he produced. This collection of papers is a tribute to a young scholar who in the very early stages of his career was already influencing the field. Most among these authors and, sometimes, collaborators, will miss out on all the new insights Laurent would have offered, and we will always like him to be around to orient our research sights.
Acknowledgements
We are sure Manés will discover a lot from this thematic issue.
For having accepted our invitation, we sincerely thank (in alphabetical order) Patricia Balaresque (France), Priscilla Bayle (France), Amélie Beaudet (South Africa, France), Anne Bertin (France), Luca Bondioli (Italy), Priscille Bouvier (France), José Braga (France, South Africa), Emiliano Bruner (Spain), Kristian J. Carlson (South Africa, USA), Marine Cazenave (South Africa, France), Habiba Chirchir (USA), Marion Cottin (France), David J. Daegling (USA), Guillaume Daver (France), Christopher M. Dean (UK), Frikkie de Beer (South Africa), Jordan Romeyer Dherbey (France), Mathieu Domalain (France), Mark R. Dowdeswell (South Africa), Jean Dumoncel (France), Benjamin Duployer (France), Metasebia Endalamaw (Ethiopia), Florian Fischer (Germany), Laura C. Fitton (UK), Martin Friess (France), Andrew H. Gee (UK), Ricardo M. Godinho (UK), Frederick E. Grine (USA), Jakobus Hoffman (South Africa), Emma Huston (USA), Tea Jashashvili (South Africa, USA), Richard A. Ketcham (USA), Roman H. Khonsari (France), Tracy L. Kivell (UK), Yutaka Kunimatsu (Japan), Renaud Lebrun (France), Mona Le Luyer (France, UK), David Lordkipanidze (Georgia), Jean-Michel Loubes (France), Damiano Marchi (Italy), Arnaud Mazurier (France), Naoki Morimoto (Japan), Wataru Morita (Japan), Masato Nakatsukasa (Japan), Christina L. Nicholas (USA), Anna Oettlé (South Africa), Paul O’Higgins (UK), Biren A. Patel (South Africa, USA), Daniel J. Proctor (USA), Blade E. Redae (Ethiopia), Brian G. Richmond (USA), Laurent Risser (France), Laura L. Shackelford (USA), Matthew M. Skinner (UK), Richard J. Smith (USA), Vitale S. Sparacello (UK, France), Nicholas B. Stephens (Germany), Randall L. Susman (USA), Christophe Tenailleau (France), John F. Thackeray (South Africa), Viviana Toro-Ibacache (Chile), Graham M. Treece (UK), Erik Trinkaus (USA), Zewdi J. Tsegai (Germany), Sébastien Villotte (France), Bernard A. Wood (USA), and Angel Zeininger (USA).
We also acknowledge the generous help provided by the following 32 colleagues having assured the anonymous revision of the manuscripts: Philip Anderson (USA), Priscilla Bayle (France), Luca Bondioli (Italy), Jen A. Bright (USA), Kristian J. Carlson (South Africa, USA), Marine Cazenave (South Africa, France), Habiba Chirchir (USA), Christopher M. Dean (UK), Florent Détroit (France), David W. Frayer (USA), Frederick E. Grine (USA), Tea Jashashvili (South Africa, USA), Tracy L. Kivell (UK), Roberto Macchiarelli (France), Damiano Marchi (Italy), Masato Nakastsukasa (Japan), Tyler G. O’Brien (USA), Naomichi Ogihara (Japan), Paul O’Higgins (UK), Rolf Quam (USA), Matthew Ravosa (USA), Lorenzo Rook (Italy), Gary Schwartz (USA), Matthew M. Skinner (UK), Matthew W. Tocheri (Canada), Zewdi J. Tsegai (Germany), Nicolas Valdeyron (France), Cynthia A. Wilczak (USA), Xiujie Wu (China), Clément Zanolli (France), Angel Zeininger (USA), Benhard Zipfel (South Africa).
Special thanks are also due to the Palevol editorial staff, especially to Sandrine Fléchel, to the Scientific Secretary, Hélène Paquet, and to the Editor-in-Chief, Michel Laurin.