250 Pages
English

Occlusal wear pattern analysis of functional morphology in Neanderthals and early Homo sapiens dentition [Elektronische Ressource] / von Luca Fiorenza

-

Gain access to the library to view online
Learn more

Description

Occlusal Wear Pattern Analysis of Functional Morphology in Neanderthals and Early Homo sapiens Dentition Dissertation zur Erlangung des Doktorgrades der Naturwissenschaften Vorgelegt beim Fachbereich Biowissenschaften der Johann Wolfgang Goethe-Universität in Frankfurt am Main von Luca Fiorenza aus Rom Frankfurt 2009 (D30) Von Fachbereich Biowissenschaften der Johann Wolfgang Goethe – Universität als Dissertation angenommen. Dekan: Prof. Dr. A. Starzinski-Powitz Gutachter: Prof. Dr. F. Schrenk and Prof. Dr. G. Weniger Datum der Disputation: 09-11-2009 ii Acknowledgements This dissertation would not have been possible without the encouragement and support of many people. I wish first to thank Ottmar Kullmer, the supervisor of my doctoral studies, for involving me in this project, for continuously motivating me and giving me precious and useful advice for the past three years. I would like also to thank my dissertation advisors, Prof. Friedemann Schrenk and Prof. Gerd-Christian Weniger for their time and participation.

Subjects

Informations

Published by
Published 01 January 2009
Reads 42
Language English
Document size 11 MB





Occlusal Wear Pattern Analysis of Functional Morphology in
Neanderthals and Early Homo sapiens Dentition



Dissertation
zur Erlangung des Doktorgrades
der Naturwissenschaften


Vorgelegt beim Fachbereich Biowissenschaften
der Johann Wolfgang Goethe-Universität
in Frankfurt am Main


von
Luca Fiorenza
aus Rom



Frankfurt 2009
(D30)













Von Fachbereich Biowissenschaften der
Johann Wolfgang Goethe – Universität als Dissertation angenommen.








Dekan: Prof. Dr. A. Starzinski-Powitz
Gutachter: Prof. Dr. F. Schrenk and Prof. Dr. G. Weniger
Datum der Disputation: 09-11-2009


ii
Acknowledgements
This dissertation would not have been possible without the encouragement and support of
many people. I wish first to thank Ottmar Kullmer, the supervisor of my doctoral studies, for
involving me in this project, for continuously motivating me and giving me precious and
useful advice for the past three years. I would like also to thank my dissertation advisors, Prof.
Friedemann Schrenk and Prof. Gerd-Christian Weniger for their time and participation.
I would like to gratefully acknowledge the following curators for access to comparative and
fossil specimens: Almut Hoffmann (Museum für Vor- und Frühgeschichte, Berlin, Germany),
Maria Teschler Nicola (Naturhistorisches Museum Wien, Vienna, Austria), Marta Dočkalová
(Moravské Zemské Muzeum, Anthropos Institute, Brno, Czech Republic), Bence Viola
(Department of Anthropology, University of Vienna, Austria), Yoel Rak (Department of
Anatomy and Anthropology, University of Tel Aviv, Israel), Fabio Parenti (Istituto Italiano di
Paleontologia Umana, Rome, Italy), Chris Stringer and Rob Kruszynski (Natural History
Museum of London, England), Angiolo del Lucchese (Museo Preistorico dei Balzi Rossi,
Ventimiglia, Italy), Loretana Salvadei (Museo Nazionale Preistorico Etnografico ―Luigi
Pigorini‖, Rome, Italy) and Erik Trinkaus (Department of Physical Anthropology at
Washington University in Saint Louis, USA).
I need also to express all my gratitude to the people of the Department of Paleoanthropology
and Messel Research at the Senckenberg Research Institute, and in particular to Christine
Hemm-Herkner for the pleasant company during the numerous trips around the world for
collecting data; to Birgit Denkel-Oswalt for her incredible patience and kindness and because
without her I would be probably lost in the German bureaucracy; to Ulrike Menz for her great
helpfulness and copy-editing the German thesis summary; to Tim Schikora for his help with
German proofreading and to Elke Pantak-Wein for her precious assistance. Moreover I give
special thanks to Jeremy Tausch for his friendship and patience for copy-editing this
manuscript and to Stefano Benazzi for his important contribution in improving the quality of
the OFA method and, of course, for his friendship. I would not be able to make any mould or
cast without the support and advice from Olaf Vogel and from all the people of the
Geological Preparation Lab and the Zoological Taxidermy Lab of the Senckenberg Museum.
Bence Viola deserves another special thank-you for his advice in dental moulding/casting, for
helping me in surface-scanning the original fossils in Brno and for providing me with the
dental casts of Bushmen, Fuegians and Australian aborigines. I owe all my gratitude to
iii
Emiliano Bruner where beyond his friendship, he helped me throughout my scientific career
since university, giving me precious advice, motivating and encouraging me to improve.
I will never stop to thank Matthew Westwood who helped me to copy-edit this manuscript. I
feel really sorry for him since I have almost forced him to read pages and pages full of
technical and ―strange‖ scientific terms. It must be really boring. Thanks mate!
I also owe a debt to the PAST (Palaeontological Statistics) community and to Prof. Brooks
Ferebee (Department of Mathematics, University Johann Wolfgang Goethe-University of
Frankfurt) for their precious support, which helped me to solve statistical problems I faced
during my PhD.
I would also like to express my gratitude for being a part of EVAN (European Virtual
Anthropology Network) which gave me the opportunity to participate in interesting scientific
events where I met many great people.
This research was supported by EU Marie Curie Training Network MRTN-CT-2005-019564
EVAN.
Last but not least, I have to thank all my friends and especially my family that despite 1000 km
of distance between us, are always with me. I am also indebted to my girlfriend Iva who always
left a hot meal on the table, understanding and supporting me despite the fact I have
―preferred‖ to spend my time with my computer in writing and re-writing my thesis instead to
be with her.

iv
Summary
Very little is known about the occlusal wear pattern in the Neanderthal posterior dentition.
Usually dental wear is closely related to the physical properties of the ingested food, and
consequently can be used to obtain information about diet. Neanderthal dietary
reconstructions have been mostly based on the analysis of accompanying faunal remains and
isotopic signatures of bones and tooth enamel, suggesting that they exploited larger portions
of animal proteins from large and medium-sized herbivores. Probably these studies may do
not reflect the bulk diet, tending to underestimate plant consumption and to overestimate
meat consumption.
In the present work the occlusal wear pattern of maxillary molars of Homo neanderthalensis
(N=19) and early Homo sapiens (N=12)have been analyzed, applying non-destructive methods
based on virtual three-dimensional polygonal models generated from surface scanning of
dental casts. The sample groups occupied different geographical areas at different
chronological times. The 3D digital tooth models were analyzed using the ―Occlusal
Fingerprint Analysis‖ (OFA) method (Kullmer et al. 2009), describing and quantifying the
occlusal wear pattern derived from two wear facet angles (dip and dip direction), wear facet
area and occlusal relief index (ORI). The OFA method provides information about the
dynamics of the occlusal relationships and their function, permitting the reconstruction of the
mandibular movements responsible for the contacts created during the chewing cycle. Since
jaw movements and diet are closely related, the results obtained, can be used to interpret the
diet of the two Pleistocene hominin species. In order to evaluate how dietary differences
influence the occlusal wear pattern, upper molars of modern hunter-gatherers (N=42) with
known diet and different dietary habits, have been included in the sample and compared with
those of Neanderthals and early Homo sapiens.
Results show that within the modern hunter-gatherers sample, the occlusal wear pattern of
carnivorous populations differs from those who relied on a mixed-diet. In particular, the study
of relative facet areas clearly distinguish meat-eaters from mixed-diet hunter-gatherers, while
ORI results and wear facet inclinations (dip angle) seem to reflect directly the abrasiveness of
the diet, including the influence of exogenous materials during food preparation.
The Neanderthal occlusal wear pattern is characterized by an ecogeographic variation,
suggesting the exploitation of different food resources. In particular Neanderthals who
inhabited relatively warm environments of southern Europe and the Near East exhibit an
occlusal wear pattern different from those of meat-eaters hunter-gatherers from tempered and
v
cooler regions, displaying some features similar to those of Bushmen. These results suggest the
exploitation of a broad variety of food sources. The analysis of the occlusal wear pattern in
Neanderthals and early Homo sapiens who inhabited Europe during the cooler Oxygen Isotope
Stage 3 (OIS3) shows many similarities between the two hominid species. These results
indicate the exploitation of similar and low-diversified food sources, based mostly on the
consumption of animal proteins, as suggested through the clear similarities with the wear
patterns found in modern meat-eaters hunter-gatherers. In both studied groups, Neanderthals
and early Homo sapiens the occlusal wear pattern is characterized by high ORI and dip angle
values, suggesting the intake of a low-abrasive diet, probably due to the absence of
sophisticated food preparation techniques introducing external silica grains, e.g. from soil
(grinding of seeds) or plant cells, as those, seen in modern hunter-gatherer populations. The
analysis of the occlusal fingerprints in Neanderthal and early European Homo sapiens upper
molars suggests that both species followed very similar adaptive dietary strategies, based on a
distinctive versatility and flexibility in the daily diet, depending on availability of resources
according to environmental circumstances.

vi
Table of Contents

Acknowledgements ......................................................................................................................... iii
Summary ............................................................................................................................................ v
Table of Contents ........................................................................................................................... vii
List of Figures .................................. xi
List of Tables ................................................................................................... xv
Abbreviations ................................. xix
1 The Neanderthals ...................................................................... 1
1.1 General Overview .................................................. 1
1.2 Neanderthal Dental Morphology......................................................... 3
1.3 Neanderthal Tooth Wear ...................................................................................................... 8
1.4 Neanderthal Diet .................................................................................................................. 10
2 Function, Morphology and Wear of Teeth during Occlusion ................................ 16
2.1 Occlusion .............................................................................................................................. 16
2.2 The Chewing Cycle .............................................................................................................. 20
2.3 Occlusal Tooth Wear ........... 23
2.4 Physical Properties of Food ............................................................................................... 25
2.5 Occlusal Wear Facets .......................................... 26
2.6 Dental Occlusal Compass ................................................................... 31
2.7 Relation between Diet and Tooth Wear ........................................... 33
2.8 A New Approach to Reconstruct the Diet of Neanderthals ......... 37
3 Materials ................................................................................................................. 39
3.1 Introduction .......................... 39
3.2 Neanderthals and early Homo sapiens sample .................................................................... 41
3.2.1 Neanderthals ..................................................................................................................... 42
3.2.2 Early Homo sapiens .......... 47
vii
3.3 Modern hunter-gatherers sample ....................................................................................... 50
4 Methods .................................................. 58
4.1 Wear Facet Terminology Used .......................................................................................... 58
4.2 Creation of 3D Digital Models 59
4.2.1 Scanning ........................................................................................................................... 59
4.2.2 Casting ............................. 61
4.2.3 Post-processing of the digital model ..................................................................................... 62
4.3 Measurements ....................................................... 64
4.3.1 Orientation ........................................................................................ 64
4.3.2 Wear facet localisation ....................................................................................................... 67
4.3.3 Area ................................. 67
4.3.4 Dip and dip direction ......................................................................................................... 68
4.3.5 Inclination ......................................................................................................................... 69
4.3.6 Dip direction ..................... 69
4.3.7 3D occlusal compass .......................................................................................................... 70
4.3.8 3D occlusal relief index ...... 71
4.4 Statistical Analysis ................................................................................................................ 73
5 Results .................................................................................... 75
5.1 Wear Facet Identification .................................................................... 75
5.2 Neanderthal Occlusal Wear Pattern .................................................................................. 75
5.3 Dental Chipping in the modern hunter-gatherers sample ............. 79
5.4 Occlusal Wear Pattern: General Overview ...................................................................... 81
5.4.1 Relative area ..................................................................................................................... 82
5.4.2 Dip angle .......................... 83
5.4.3 3D Occlusal Relief Index .................................................................................................. 84
5.4.4 Dip direction ..................................................................................................................... 86
5.5 Modern hunter-gatherers .................................................................................................... 86
viii
5.5.1 Relative area ..................................................................................................................... 87
5.5.2 Dip angle .......................... 91
5.5.3 Occlusal Relief Index ......................................................................................................... 92
5.5.4 Dip direction ..................... 92
5.6 Neanderthals ......................................................................................................................... 94
5.6.1 Geographical grouping ........................................................................................................ 95
5.6.2 Relative area ..................................................................................................................... 96
5.6.3 Dip angle .......................... 99
5.6.4 3D Occlusal Relief Index ................................................................................................ 100
5.6.5 Dip direction ................................................................................................................... 100
5.7 Early Homo sapiens ............... 101
5.7.1 Geographical grouping ...................................................................................................... 102
5.7.2 Relative area ................................................................................................................... 103
5.7.3 Dip angle ........................ 105
5.7.4 3D Occlusal Relief Index ................................................................................................ 106
5.7.5 Dip direction ................................................................................................................... 106
5.8 Comparison between Neanderthals, Early Homo sapiens and modern hunter-
gatherers ..................................................................................................................................... 107
5.8.1 Relative area ................................................................................................................... 107
5.8.2 Tooth morphology ............ 108
5.8.3 Dip angle ........................................................................................................................ 109
5.8.4 3D Occlusal Relief Index ................................ 110
5.8.5 Dip direction ................................................................................................................... 110
5.9 Comparison within the human fossil sample considering different vegetation
areas…. ...................................................................................................................................... 111
5.9.1 Relative area ................................................................................................................... 111
5.9.2 Dip angle ........................ 113
5.9.3 3D Occlusal Relief Index ................................................................................................ 114
ix
5.9.4 Dip direction ................................................................................................................... 114
5.10 Comparison of meat-eaters and mixed-diet hunter-gatherers with the fossil
sample… .................................................................................................................................... 114
5.10.1 Relative area ................................................................................................................. 115
5.10.2 Dip direction ................. 117
6 Discussion ............................................................................................................. 118
6.1 General Functional Aspects of the Occlusal Wear Pattern ......... 118
6.1.1 Occlusal morphology ......................................................................................................... 118
6.1.2 Dental Occlusal Compass 119
6.1.3 Occlusal Relief ................................................................................................................. 120
6.1.4 Function of the Carabelli cusp .......................... 120
6.2 Relationship between Tooth Morphology and Occlusal Wear Pattern ..................... 121
6.3 Ecogeographical variation within Neanderthals, early Homo sapiens and modern
hunter-gatherers ........................................................................................................................ 125
6.4 Diet reconstruction derived from occlusal wear pattern analysis ............................... 130
6.4.1 Diet in the modern hunter-gatherers .................................................................................. 130
6.4.2 Reconstruction of the diet of Neanderthals and early Homo sapiens ................................... 135
6.4.3 Food preparation, cultural habits and paramasticatory activities ........ 140
6.5 Food competition between Neanderthals and early Homo sapiens ............................... 143
7 Conclusion ............................................................................................................ 147
Bibliography ................................ 151
Appendix A. Surface scanning ............................................................................................... 175
Appendix B. OFA measurements onto 3D polygonal models ..................................... 183
Appendix C. Neanderthal and early Homo sapiens occlusal wear pattern .............. 192
Appendix D. Statistical analysis: Tables ............................................................................. 196
Zusammenfassung ........................................................ 224


x