DENTAL MICROWEAR AND DIET IN GRIPHOPITHECUS ALPANL TANIA CHRISTINE KING. Thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy. University College London. University of London. January 1997. ProQuest Number: 10017773 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest. ProQuest 10017773 Published by ProQuest LLC(2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. Microform Edition © ProQuest LLC. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 ABSTRACT Examination of microscopic wear marks on the surface of teeth (dental microwear) provides information about the main components of an animal’s diet. Inferences can be made about the diet of extinct species by comparing the dental microwear patterns of fossil samples with those of present-day groups whose diet is known. This thesis examines the dental microwear of Griphopithecus alpani, a 15 Ma fossil hominoid from the Miocene site of Pasalar in north-western Turkey. The micro wear patterns of G. alpani are compared to three extant hominoid taxa - Gorilla gorilla gorilla. Pan troglodytes verus, and Pongo pygmaeus pygmaeus. Results indicate that there is no close dietary analogue to the fossil hominoids among the extant groups. However, the analysis suggests that the diet of Griphopithecus alpani was more similar to that of Pongo, which consumes mainly fruit and the occasionally hard and unripe fruits and nuts, than to the other living hominoids examined in this study. The high percentages of pits displayed by G. alpani indicate that it was ingesting harder fruits and/or objects than the extant hominoids, and it is similar in this respect to Graecopithecus freyhergi, a Miocene hominoid from Greece. There were consistent variations in microwear patterns between the different facets examined in this study. The results of this study do not indicate variation in dental micro wear according to sex or age. Experiments were carried out to investigate the effects of taphonomic agents, such as exposure to acids or abrasion by sediment, on dental microwear. Results indicate that post-mortem processes can be readily identified. This study also develops a procedure and software for the correction of foreshortened micro wear features. Feature types and dimensions may vary before and after correction, but frequencies of features do not differ. TABLE OF CONTENTS ABSTRACT...............................................................................................................................2 TABLE OF CONTENTS........................................................................................................4 LIST OF FIGURES................................................................................................................. 8 LIST OF TABLES................................................................................................................. 11 ACKNOWLEDGEMENTS..................................................................................................15 CHAPTER 1: INTRODUCTION.......................................................................................19 1.1 Project A im s.............................................................................................................................................22 1.2 T hesis O rganisation ........................................................................................................................... 23 CHAPTER 2; LITERATURE REVIEW.........................................................................27 2.1 Jaw m o vem ents , the chew ing c ycle , a n d w ear fa c e t s ..................................................27 2.1.1 Wear Facet Studies....................................................................................................27 2.1.2 The Masticatory Cycle.............................................................................................. 31 2.1.3 Attrition and Abrasion .............................................................................................. 41 2.1.4 Comminution.............................................................................................................. 43 2.1.5 Summary.................................................................................................................... 44 2.2 D ental micro w ear a n d diet ............................................................................................................46 2.2.1 Molar occlusal microwear and diet......................................................................... 46 2.2.2 Non-occlusal molar microwear............................................................................... 58 2.2.3 Incisor microwear ......................................................................................................59 CHAPTER 3: MATERIALS AND METHODS............................................................. 60 3.1 T he S t u d y S a m p l e ................................................................................................................................ 60 3.1.1 The extant hominoid sample .....................................................................................60 3.1.2 The fossil sample ...................................................................................................... 77 3.2 S pecimen S el e c t io n ..............................................................................................................................77 3.3 R eplication Pr o c e d u r e .....................................................................................................................79 3.4 The Sc a nn in g E lectron M icroscope (S E M )......................................................................... 81 3.5 SEM Ex a m in a tio n O f S pec im en s ...................................................................................................88 3.6 W ear St a g e .............................................................................................................................................. 91 3.7 S urfaces E x a m in e d ..............................................................................................................................92 3.8 F eature M e a s u r e m e n t ...................................................................................................................... 95 3.9 Correction O f Foreshortened F e a t u r e s ............................................................................100 3.10 Feature Classification ................................................................................................................108 3.11 In tr a -O bser v er E r r o r ............................................................................................................... 109 3.12 D ata A n a l y s is ................................................................................................................................... 113 3.12.1 Analysis o f microwear characteristics.................................................................115 3.12.2 Sex and Wear stage................................................................................................117 CHAPTER 4: THE EFFECTS OF TAPHONOMIC PROCESSES ON DENTAL MICROWEAR..................................................................................................118 4.1 Introduction .........................................................................................................................................118 4.2 T he P r o b l e m .......................................................................................................................................... 120 4.3 M aterials A n d M e t h o d s ............................................................................................................... 123 4.3.1 Acid erosion .............................................................................................................124 4.3.2 Alkali erosion .......................................................................................................... 125 4.3.3 Sediment abrasion ...................................................................................................126 4.4 R e s u l t s .....................................................................................................................................................127 4.4.1 Acid erosion............................................................................................................ 127 4.4.2 Alkali erosion.......................................................................................................... 130 4.4.3 Sediment abrasion...................................................................................................130 4.5 Co m pariso n W ith Pa s a l a r ........................................................................................................... 145 4.6 D is c u s s io n .............................................................................................................................................149 4.6.1 The effect o f acids on dental microwear..............................................................