EVOLUTION OF THE PECTORAL GIRDLE AND FORELIMB IN SAUROPODOMORPHA (DINOSAURIA, SAURISCHIA): OSTEOLOGY, MYOLOGY AND FUNCTION von Dipl.-Geol. Kristian Remes Dissertation der Fakultät für Geowissenschaften der Ludwig-Maximilians-Universität München zur Erlangung des Doktorgrades (Dr. rer. nat.) Eingereicht zur Beurteilung am 06.12.2007 Betreuer: PD Dr. Oliver Rauhut, Ludwig-Maximilians-Universität München Zweitgutachter: Prof. Dr. Martin Sander, Rheinische Friedrich-Wilhelms-Universität Bonn Datum der mündlichen Prüfung: 21.04.2008 温子、真摯な支えとその愛に。 REMES Sauropodomorph forelimb evolution 5 0 Contents 0 Contents __________________________________________________ 5 Anatomical abbreviations 9 Institutional abbreviations 12 1 Introduction ______________________________________________ 14 2 Material and Methods ______________________________________ 24 3 A review of archosaurian forelimb musculature: The fundament for reconstructions in extinct taxa _______________ 34 Introduction 34 General theoretical aspects of phylogenetic inference of musculature 35 Variation and the choice of extant sample taxa 37 Archosaurian forelimb myology 39 I. Cingulo-axial muscles 41 1. M. cucullaris (C) 41 2. M. rhomboideus (R) 43 3. M. levator scapulae (LS) 45 4. M. serratus superficialis (SS) 47 5. M. serratus profundus (SP) 50 6. M. costocoracoideus (CC) 52 7. M. sternocoracoideus (StC) 54 II. Humeral muscles 56 8. M. deltoideus scapularis (DS) 56 9. M. deltoideus clavicularis (DC) 57 10. M. coracobrachialis (CB) 61 11. M. supracoracoideus (SC) 63 12. M. pectoralis (P) 66 13. M. latissimus dorsi (LD) 69 14. M. teres major (TM) 71 15. Mm. scapulohumerales (SH) 73 16. M. subcoracoscapularis (SCS) 75 III. Antebrachial muscles 79 17. M. triceps brachii (TB) 79 18. M. biceps brachii (BB) 84 19. M. humeroradialis (HR) 87 20. M. brachialis (B) 88 21. M. supinator (S) 91 6 Sauropodomorph forelimb evolution REMES 22. M. abductor radialis (AR) 92 23. M. ectepicondylo-ulnaris (EctU) 94 24. M. pronator teres (PT) 95 25. M. entepicondylo-ulnaris (EntU) 98 26. M. pronator quadratus (PQ) 99 IV. Manual muscles 101 a) Antebrachial musculature acting on the hand 101 27. M. extensor carpi radialis (ECR) 102 28. M. extensor carpi ulnaris (ECU) 103 29. M. supinator manus (SM) 106 30. M. extensor digitorum communis (EDC) 108 31. M. flexor carpi radialis (FCR) 110 32. M. flexor carpi ulnaris (FCU) 111 33. M. flexor digitorum longus (FDL) 112 b) Intrinsic musculature of the hand 115 34. Mm. extensores digitorum superficiales (EDS) 115 35. Mm. extensores digitorum profundi (EDP) 118 36. M. abductor pollicis brevis (APB) 120 37. M. abductor digiti V (AD5) 121 38. Mm. flexores digitorum superficiales (FDS) 121 39. M. flexor pollicis brevis (FPB) 123 40. M. flexor digiti V (FD5) 125 41. Mm. lumbricales (L) 127 42. Mm. flexores digitorum profundi (FDP) 128 43. Mm. interossei (I) 130 Conclusions 131 4 Forelimb anatomy of basal archosaurs and ornithodirans: Facts and Fictions _______________________________________ 133 Introduction 133 Data quality 133 Anatomy 137 Basal Archosauria: Euparkeria capensis 137 Basal Dinosauriformes: Lewisuchus admixtus 143 Comments on other forms 146 Muscle reconstructions 148 Euparkeria 149 Lewisuchus 153 Discussion 154 Conclusions 159 REMES Sauropodomorph forelimb evolution 7 5 Structure and function of the forelimb in basal saurischians and early theropods _______________________________________ 161 Introduction 161 Anatomy 163 Basal saurischians 163 Basal theropods 177 Basal ornithischians 181 Muscle reconstructions 183 Discussion 194 Shoulder region 194 Arm 195 Manus 199 Body proportions 201 Conclusions 203 6 The pectoral girdle and forelimb of basal sauropodomorphs: Anatomy and functional interpretation _______________________ 204 Introduction 204 Anatomy 206 Saturnalia tupiniquim 206 Other basal sauropodomorphs 209 Muscle reconstructions 215 Saturnalia 215 Efraasia 218 Discussion 220 Conclusions 223 7 ‘Prosauropod’ forelimb anatomy and the transition to Sauropoda _ 224 Introduction 224 Anatomy 226 Non-sauropod sauropodomorphs 227 Antetonitrus ingenipes and other stem-sauropods 236 Muscle reconstructions 243 Discussion 246 Osteology and bauplan 246 Myology 252 Conclusions 255 8 Sauropodomorph forelimb evolution REMES 8 Functional morphology of the pectoral girdle and forelimb in basal sauropods _______________________________________ 257 Introduction 257 Data quality 258 Anatomy 264 Patagosaurus and other non-mamenchisaurid basal sauropods 264 Mamenchisauridae 275 Muscle reconstructions 276 Discussion 281 Osteology and bauplan 281 Myology 287 Conclusions 291 9 Forelimb evolution in sauropodomorphs: Combining functional morphology and phylogeny ____________ 293 Introduction 293 Phylogeny 293 Evolutionary transformations 297 Pectoral girdle 297 Humerus 304 Elbow joint 308 Antebrachium 313 Manus 313 Conclusions 316 10 Summary _______________________________________________ 320 Acknowledgements 322 11 Bibliography_____________________________________________ 323 Appendix: Myological overview _______________________________ 349 Lebenslauf (Curriculum vitae)__________________________________ 353 REMES Sauropodomorph forelimb evolution 9 Anatomical abbreviations Osteology ac accessory distal condyles on fcm craniomedial fossa of coracoid humerus fmc facet for M. cucullaris acr acromion fmcb fossa for M. coracobrachialis adp apex of deltopectoral crest (brevis) ar acromial ridge fmdc facet for M. deltoideus ambb attachment of M. biceps clavicularis brachii fmds fossa for M. deltoideus ameu attachment of M. scapularis entepicondylo-ulnaris fmeu facet for M. ectepicondylo- amhr attachment of M. ulnaris humeroradialis fmfdl facet for origin of M. flexor amsc attachment of M. supracora- digitorum longus coideus fmfdp fossa for M. flexor digitorum amtb attachment of M. triceps profundus brachii fmpq fossa for M. pronator amtbc attachment of coracoidal quadratus anchor of M. triceps brachii fmsc fossa for M. supracoracoideus caput coracoscapulare (pars scapularis) bt biceps tubercle on coracoid fmscs fossa for M. subcoracoideus ccl contact for clavicle fmsh fossa(e) for M. cdp caudodistal process on scapulohumeralis scapula fmsm facet for M. supinator manus cdr distal condyle of radius fmsp facet for M. serratus profundus cdu distal condyle of ulna fmss facet for M. serratus ce centrale superficialis cf caudal flange on scapular fmssc facet for M. subscapularis blade fmtbh facet(s) for M. triceps brachii chr humeral cotyle of radius capiti humerales mediales chu humeral cotyle of ulna fmtbhm facet for M. triceps brachii cid caudal intercondylar caput humerale mediale depression fr radial fossa on ulna cl clavicle ft flexor tubercle cne centrale fvm ventromedial fossa of coracoid co coracoid gl glenoid cavity cocp caudal process of coracoid h humerus cof coracoid foramen hh humeral head cp cranial process of ulna hlt lateral tubercle of humerus cpt caudoproximal tubercle of hmt medial tuberosity of humerus radius hrc radial condyle of humerus crdt craniodistal tubercle of radius huc ulnar condyle of humerus crp craniodistal process on i intermedium scapula icb impressio m. coracobrachialis crr cranial ridge on radius icl interclavicle dc distal carpal(s) imr intermuscular ridge(s) dcr dorsocranial ridge on lepc ectepicondyle humerus lfmc lateral flange(s) of de distal expansion of scapula metacarpal(s) did dorsal intercondylar lp lateral process of ulna depression m manus dp deltopectoral crest mc metacarpal drc distal radial condyle mcdc metacarpal distal condyles ep extensor pit(s) mcep metacarpal extensor pit(s) et extensor tubercle(s) mclp metacarpal ligament pit(s) fc caudal facet on ulna mepc entepicondyle ol olecranon process 10 Sauropodomorph forelimb evolution REMES pcs processus sternocoracoidei ph phalanx, phalanges plp phalangeal ligament pit(s) pi pisiform pua proximal ulnar articular facet of radius r radius rae radiale rcp radial caudoproximal process rcr radial cotyle of radiale rct radial cranioproximal tubercle rnsc recessus for N. supracoracoideus rt radial tubercle (= tmb?) rup radial ulnar process sa sternocoracoidal articulation sc scapula sca scapulocoracoidal articulation scb scapular blade sch scapular head scs scapulocoracoidal suture sgb supraglenoidal buttress sgf subglenoidal fossa on coracoid smld scar for M. latissimus dorsi ssc suprascapula ssca suprascapular articulation ste sternum stp sternal plate tmb tubercle for M. brachialis tmbb tubercle for M. biceps brachii tmtbs tubercle for M. triceps brachii caput scapulare ua ulnar articular facet on radius ucu ulnar cotyle of ulnare ul ulna ule ulnare un ungual(s) urt ulnar radial tubercle vip ventral intercondylar pit REMES Sauropodomorph forelimb evolution 11 Myology AD5 M. abductor digiti V LDcran M. latissimus dorsi cranialis AdA M. adductor alulae LS M. levator scapulae ADM M. abductor digiti majoris LSHL Lig. scapulohumerale laterale AP M. abductor pollicis LSSI Lig. Sternoscapulare AR M. abductor radialis internum B M. brachialis P M. pectoralis BB M. biceps brachii PA palmar aponeurosis C M. cucullaris PQ M. pronator quadratus CB M. coracobrachialis PT M. pronator teres CBbrev M. coracobrachialis brevis PT1 M. pronator superficialis CBcran M. coracobrachialis cranialis PT2 M. pronator profundus CBlong M. coracobrachialis longus R M. rhomboideus CC M. costocoracoideus S M. supinator CCprof M. costocoracoideus SC M. supracoracoideus profundus SCcor M. supracoracoideus pars CCsup M. costocoracoideus coracoideus superficialis SCscap M. supracoracoideus pars DC M. deltoideus