Inferring lifestyle for Aves and Theropoda: A model based on curvatures of extant avian ungual bones A thesis submitted to the University of Manchester for the degree of Master of Science by Research in the Faculty of Science & Engineering 2019 Savannah E. Cobb School of Earth and Environmental Sciences Contents List of Figures.........................................................................................................................4-5 List of Tables..............................................................................................................................6 List of Abbreviations..............................................................................................................7-8 Abstract......................................................................................................................................9 Declaration...............................................................................................................................10 Copyright Statement...............................................................................................................11 Acknowledgements..................................................................................................................12 1 Literature Review........................................................................................................13 1.1 Avians, avialans, and theropod dinosaurs..........................................................13 1.2 Comparative study and claws............................................................................18 1.2.1 Claws, locomotion, and ecology...............................................................19 1.2.2 Quantifying claw form..............................................................................22 1.2.3 Quantifying behaviour..............................................................................27 1.2.4 Comparability across taxa and structures.................................................28 1.2.5 Internal structure of the claw....................................................................31 1.2.6 Techniques for quantitative analysis........................................................33 2 Introduction…..............................................................................................................34 3 Materials and Methods................................................................................................39 3.1 Development of the model.................................................................................39 3.1.1 X-ray techniques.......................................................................................41 3.1.2 Geometric measurements..........................................................................45 3.1.3 Statistical analysis.....................................................................................48 3.2 Application of the model...................................................................................52 4 Results...........................................................................................................................54 4.1 Measurements and raw data……………………………………….…………..54 4.2 Relationship with body mass.............................................................................63 4.3 Relationship with phylogeny.............................................................................70 4.4 Claw geometry and behavioural category.........................................................73 4.5 Comparison with fossil taxa..............................................................................84 2 5 Discussion.....................................................................................................................90 5.1 Findings on claw ecomorphology......................................................................90 5.2 Potential sources of error...................................................................................92 5.2.1 Effects of scaling on form.........................................................................92 5.2.2 Phylogenetic influence on form................................................................95 5.2.3 Overlapping ranges: form and behaviour.................................................97 5.2.4 Conflicting predictions.............................................................................99 5.2.5 Incomparable fossil morphologies and behaviours................................102 5.3 Predictions for fossil taxa................................................................................103 5.3.1 Archaeopteryx.........................................................................................105 5.3.2 Maniraptoran dinosaurs..........................................................................106 5.3.3 Avialans and avians................................................................................112 6 Conclusions.................................................................................................................115 References.......................................................................................................................119-129 Appendix……………………………………………………………………………….130-141 A Radiographs………………………………………………………………….130 B Photographs of fossil claws………………………………………………….139 Word count (including tables): 26,615 3 List of Figures 1.1 Maniraptoran taxa with apparent gliding adaptations.....................................................................................................................15 1.2 Proposed mode of climbing for theropod dinosaurs......................................................16 1.3 Methods of quantifying claw curvature.........................................................................23 1.4 Methods of calculating claw arc……………………………………............................24 1.5 Internal structure of the claw.........................................................................................27 2.1 Claw radius versus claw arc……………………………………………...…………...37 3.1 The Nomad Pro Radiography Unit.…………………………………………………...42 3.2 Radiographs showing layering process.........................................................................43 3.3 Positions for operating the Nomad Pro Radiography Unit............................................44 3.4 Methods of determining claw angle for sheaths and ungual bones…………………...46 3.5 Alternate method of measuring ventral curvature to the exclusion of the toe pad……47 3.6 Reconstructed fossil ungual bones.................................................................................53 4.1 Histograms showing distribution of body mass and log-transformed body mass for extant avians…………………………………………………………………………..64 4.2 Box plots showing relationship between body mass and ecological group…………...67 4.3 Results of Abouheif’s test for phylogenetic autocorrelation in claw angles……….....71 4.4 Results of Abouheif’s test for phylogenetic autocorrelation in ecological group.........72 4.5 Curvatures of D-III ungual bones and claw sheaths for all extant taxa……………….76 4.6 Radiographs of avian D-III claws exhibiting significant morphological disparity…...77 4.7 LD axes based on curvatures of D-III ungual bones and claw sheaths for all extant and fossil taxa……………………………………………………………………...………80 5.1 Regression plots for claw angle against body mass.......................................................93 5.2 Right and left pedal D-III claws of specimens that received conflicting predictions……………………………………………………………………………100 5.3 Specimen of Microraptor gui (IVPP V17972) with remains of enantiornithine bird preserved in abdominal cavity and close-up of line drawing of IVPP V17972……..110 A.1 Accipiters…………………………………………………………………………….130 A.2 Falcons……………………………………………………………………………….130 A.3 Strigiformes………………………………………………………………………….131 A.4 Palaeognathae………………………………………………………………………..131 4 A.5 Otidiformes…………………………………………………………………………..131 A.6 Water birds…………………………………………………………………………...132 A.7 Cuculiformes…………………………………………………………………………132 A.8 Galliformes…………………………………………………………………………..132 A.9 Gruiformes………………………………………………………………………...…133 A.10 Parrots………………………………………………………………………………..133 A.11 Hornbills, rollers, and kingfishers…………………………………………………...133 A.12 Musophagiformes, Caprimulgiformes, Pterocliformes, Opsithocomiformes………..134 A.13 Columbiformes………………………………………………………………………134 A.14 Corvids………………………………………………………………………………134 A.15 Woodcreepers…………………………………………………………………...135-136 A.16 Toucans…………………………………………………………………………136-137 A.17 Woodpeckers and barbets……………………………………………………………137 A.18 Squamates……………………………………………………………………………138 B.1 Avialans……………………………………………………………………………...139 B.2 Dromaeosaurids……………………………………………………………………...140 B.3 Troodontids…………………………………………………………………………..140 B.4 Anchiornithids……………………………………………………………………….141 B.5 Ornithomimidae, Tyrannosauridae…………………………......................................141 5 List of Tables 4.1 Sampled extant taxa………………………………………………………………..54-59 4.2 Sampled fossil taxa...................................................................................................59-60 4.3 Variability between methods of measuring claw angle............................................61-62 4.4 Shapiro-Wilk normality test on claw angles and body mass.........................................63 4.5 Linear regressions between body mass and claw angle...........................................64-65 4.6 ANOVAs and Tukey tests for body mass and ecological group…………………..68-69 4.7 ANOVAs