SCRATCH-DIGGING IN THE CRETACEOUS BASAL ORNITHOPOD DINOSAUR ORYCTODROMEUS CUBICULARIS: EVIDENCE FROM MORPHOMETRIC ANALYSES AND RECONSTRUCTION OF THE FORELIMB MUSCULATURE by Jamie Lynn Fearon A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Earth Science MONTANA STATE UNIVERSITY Bozeman, Montana May 2013 ©COPYRIGHT by Jamie Lynn Fearon 2013 All Rights Reserved ii APPROVAL of a thesis submitted by Jamie Lynn Fearon This thesis has been read by each member of the thesis committee and has been found to be satisfactory regarding content, English usage, format, citation, bibliographic style, and consistency and is ready for submission to The Graduate School. David J. Varricchio Approved for the Department of Earth Sciences David Mogk Approved for The Graduate School Ronald W. Larsen iii STATEMENT OF PERMISSION TO USE In presenting this thesis in partial fulfillment of the requirements for a master’s degree at Montana State University, I agree that the Library shall make it available to borrowers under rules of the Library. If I have indicated my intention to copyright this thesis by including a copyright notice page, copying is allowable only for scholarly purposes, consistent with “fair use” as prescribed in the U.S. Copyright Law. Requests for permission for extended quotation from or reproduction of this thesis in whole or in parts may be granted only by the copyright holder. Jamie Lynn Fearon May 2013 iv TABLE OF CONTENTS 1. INTRODUCTION ...........................................................................................................1 Focus of Study .................................................................................................................1 Purpose of Study ..............................................................................................................2 2. LITERATURE REVIEW ................................................................................................5 Morphology of Digging ...................................................................................................7 Forelimb Musculature ......................................................................................................9 Digging in Dinosaurs .....................................................................................................11 Phylogenetic Framework ...............................................................................................12 Morphometrics ...............................................................................................................14 3. MORPHOMETRIC ANALYSIS OF THE FORELIMB AND PECTORAL GIRDLE OF THE CRETACEOUS ORNITHOPOD DINOSAUR ORYCTODROMEUS CUBICULARIS AND IMPLICATIONS FOR DIGGING ................................................................................16 Contributions of Authors and Co-Authors Page ............................................................16 Manuscript Information Page ........................................................................................17 Title Page .......................................................................................................................18 Abstract ..........................................................................................................................18 Introduction ....................................................................................................................19 Materials and Methods ...................................................................................................23 Traditional Morphometric Analysis .......................................................................24 Geometric Morphometric Analysis ........................................................................27 Results ............................................................................................................................31 Traditional Morphometrics ....................................................................................31 Humerus .....................................................................................................31 Scapula .......................................................................................................34 Coracoid .....................................................................................................36 Geometric Morphometrics .....................................................................................39 Humerus .....................................................................................................39 Scapula .......................................................................................................42 Coracoid .....................................................................................................44 Discussion ......................................................................................................................47 Morphological Trends ............................................................................................47 Humerus .....................................................................................................47 Scapula .......................................................................................................49 Coracoid .....................................................................................................51 General Morphological Trends ..................................................................52 v TABLE OF CONTENTS – CONTINUED Morphologic Specializations in Oryctodromeus .......................................52 Implications for Digging ........................................................................................54 Limitations of this Study ........................................................................................55 Conclusion .....................................................................................................................56 Acknowledgements ........................................................................................................58 Tables .............................................................................................................................59 Figures............................................................................................................................62 References ......................................................................................................................75 4. RECONSTRUCTION OF THE FORELIMB MUSCULATURE OF THE CRETACEOUS ORNITHOPOD DINOSAUR ORYCTODROMEUS CUBICULARIS: IMPLICATIONS FOR DIGGING...................79 Contributions of Authors and Co-Authors Page ............................................................79 Manuscript Information Page ........................................................................................80 Title Page .......................................................................................................................81 Abstract ..........................................................................................................................81 Introduction ....................................................................................................................82 Materials and Methods ...................................................................................................86 Results ............................................................................................................................90 Axial Musculature ..................................................................................................91 Levator Scapulae (LSC) .............................................................................91 Serratus Superficialis (SES) .......................................................................91 Sternocoracoideus and/or Costocoracoideus Superficialis (STC or CCS) .......................................................................92 Trapezius (TRA) ........................................................................................93 Appendicular Musculature .....................................................................................94 Biceps Brachii (BIC)..................................................................................94 Brachialis (BRA) .......................................................................................95 Coracobrachialis Brevis (CBB) .................................................................96 Deltoideus Clavicularis (DCL) ..................................................................96 Deltoideus Scapularis (DSC) .....................................................................97 Latissimus Dorsi (LAT) .............................................................................98 Pectoralis (PEC) .........................................................................................99 Scapulohumeralis Caudalis (SHC) ..........................................................100 Subcoracoideus (SBC) .............................................................................100 Subscapularis (SBS).................................................................................101 Supracoracoideus (SCC) ..........................................................................102 Teres Major (TMA) .................................................................................103 Triceps Brevis (TRIB) .............................................................................104