Durham E-Theses A comparative analysis of the wrist and ankle morphology of hominoids and lorisids, with implications for the evolution of hominoid locomotion Read, Catriona S. How to cite: Read, Catriona S. (2001) A comparative analysis of the wrist and ankle morphology of hominoids and lorisids, with implications for the evolution of hominoid locomotion, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/3775/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 A Comparative Analysis of the Wrist and Ankle Morphology of Hominoids and Lorisids, with Implications for the Evolution of Hominoid Locomotion A Dissertation presented by Catriona S. Read to The Graduate School For the degree of Master of Science m Biological Anthropology Department of Anthropology University of Durham September 2001 The co11yright of this thesis rests with the author. No quotation from it should be published in any form, including Electronic and the Internet, without the author's prior written consent. All information derived from this thesis must be acknowledged appropriately. Declaration This thesis is the result of my own work, and no part of it has previously been submitted for a degree at any University. Material from the published or unpublished work of others, which is referred to in the thesis, is credited to the source in the text. A Comparative Analysis of the Wrist and! Ankle Morphology of Hominoids and! Lorisids, with Implications for the Evolution of Hominoid Locomotion by Catriona S. Read m Biological Anthropology Department of Anthropology University of Durham October 2001 There has been considerable debate concerning the adaptive significance of hominoid postcranial anatomy. One of the hypotheses promoted is that the early hominoids were adapted to a loris-like deliberate quadrupedalism. The aim of the analysis reported here is to test this hypothesis by examining features of the wrist and ankle anatomy of lorisids and hominoids that pertain to increased joint mobility, in a comparative context with other arboreal quadrupeds. These characters are then compared with the Proconsulidae from the early Miocene to discern any similarities between these taxa and the lorisids and/or hominoids. Fourteen characters were examined, related to the ulnocarpal and radioulnar articulations, and the talocrural, subtalar and midtarsal joints, across four lorisid and four hominoid genera, and a selection of primates from the other major groups. Original measurements were taken for two hundred and twenty-nine neontological specimens in total, from fourteen genera. Indices were devised and compared by statistical analysis. The results suggest that lorisids and hominoids are similar in some of the characters examined, but differ in others. The proconsulids show varying degrees of similarity across the features, to the hominoids and lorisids. The results support a hypothesis that an early hominoid ancestor did indeed have similar functional adaptations to those of extant lorisids, but not across the whole suite of characters examined. It is therefore reasonable to assume that the ancestral hominoid locomotor pattern showed resemblances to that of the extant lorisids, but was not identical. 11 Acknowledgements I would like to take this opportunity to thank those who assisted me during the course this study. Firstly, I thank Bob Randall at the American Museum of Natural History, New York, and Linda Gordon at the National Museum of Natural History, Washington D. C. for allowing me access to the extant primate collections in their care, and for the assistance provided by themselves and their staff during my visits. I would also like to thank John Langdon, Department of Biology at the University of Indianapolis, who very kindly allowed me access to his unpublished fossil data, without which much of the fossil inference would have been impossible. My thanks go especially to my supervisor, Todd C. Rae, for his constant advice and support throughout this study, and most particularly for keeping me focused when things did not go exactly to plan. It is primarily due to Todd that I developed my cunent interests, and his apparent faith in me has been very encouraging. Finally, I would like to thank my family, who have been hugely supportive throughout, and Calum, who has shown extreme tolerance of, and amusement at, his Mummy's unusual interests. Ill Table of Contents Abstract of the Dissertation ................................................................................. ii Acknowledgements .............................................................................................. iii Table of Contents .................................................................................................. iv Table of Figures ..................................................................................................... vi Introduction ............................................................................................................ l Objectives ....................................................................................................................... 1 Thesis outline .................................................................................................................. 3 Primate locomotion: an overview of classification ......................................................... 3 Locomotor diversity across the major primate divisions ................................................ 7 Locomotor adaptations in the early Miocene hominoids ................................. 18 The early Miocene hominoids: introduction ................................................................. 18 Previous analyses of early Miocene hominoid postcrania ............................................ 20 Locomotor hypotheses .................................................................................................. 29 Wrist and ankle morphology .............................................................................. 42 Extant hominoid wrist morphology in a comparative context.. ................................... .42 Extant hominoid ankle morphology in a comparative context ..................................... 49 The lorisid wrist and ankle joints .................................................................................. 58 The early Miocene hominoid wrist.. ............................................................................. 62 The early Miocene hominoid ankle .............................................................................. 66 Aims and Objectives ............................................................................................ 70 Methods and Materials ........................................................................................ 73 Neontological specimens .............................................................................................. 73 Fossil speciinens ........................................................................................................... 73 Measurements ............................................................................................................... 75 Derived Ineasureinents .................................................................................................. 82 Statistical analysis ......................................................................................................... 88 Results ................................................................................................................... 89 Ulnocarpal joint ................................... : ........................................................................ 89 Radioulnar joint ............................................................................................................ 97 Talocrural joint ........................................................................................................... 107 Subtalar joint.. ............................................................................................................. 116 Talar head and neck .................................................................................................... 125 IV Discussion and conclusions ............................................................................... 138 Hominoid characteristics ............................................................................................ 138 Lorisoid characteristics ............................................................................................... 147 Comparison between the hominoids and lorisids ....................................................... 150 Proconsulids in a comparative context ....................................................................... 153 Evaluation ..................................................................................................................