Comparative Three-Dimensional Moment Arm Analysis of the Sauropod Forelimb: Implications for the Transition to a Wide-Gauge Stance in Titanosaurs
| Autor: | Ada J. Klinkhamer, Stephen F. Poropat, Trish Sloan, Stephen Wroe, Heinrich Mallison |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Models Anatomic Histology Titanosaur Posture Diamantinasaurus Dinosaurs Diplodocid 03 medical and health sciences 0302 clinical medicine Forelimb medicine Animals Ground reaction force Range of Motion Articular Process (anatomy) Ecology Evolution Behavior and Systematics Sauropoda biology Apatosaurus Fossils Reproducibility of Results Anatomy biology.organism_classification Adaptation Physiological Biological Evolution Biomechanical Phenomena 030104 developmental biology medicine.anatomical_structure 030217 neurology & neurosurgery Biotechnology |
| Zdroj: | Anatomical record (Hoboken, N.J. : 2007). 302(5) |
| ISSN: | 1932-8494 |
| Popis: | The evolution of extraordinarily large size among Sauropoda was associated with a number of biomechanical adaptations. Changes in muscle moment arms undoubtedly accompanied these adaptations, but since muscles rarely fossilize, our ability to understand them has been restricted. Here, we use three-dimensional (3D) musculoskeletal modeling to reconstruct and quantitatively assess leverage of forelimb muscles in the transition from the narrow-gauge stance of basal sauropods to a wide-gauge stance in titanosaurs. A comparative analysis is conducted on three neosauropods: the narrow-gauge diplodocid Apatosaurus louisae, the intermediate-gauge titanosariform Giraffatitan brancai, and the wide-gauge titanosaur Diamantinasaurus matildae. In this study, moment arm magnitudes and corresponding morphological evidence indicates multiple changes across the narrow-gauge to wide-gauge transition in sauropods. High shoulder adduction was found in Diamantinasaurus, suggesting functional changes for supporting a wider stance and a limb less aligned with ground reaction force. High leverage in shoulder extension of Diamantinasaurus and Giraffatitan is possibly related to the increased use of the forelimb in forward propulsion with an anterior shift in center of mass. In addition, the prominence of the olecranon process in Diamantinasaurus produced high moment arm leverage in elbow flexion and extension, suggesting titanosaurs might have maintained a more flexed forelimb posture and displayed an increased degree of maneuverability. Other results are more variable between taxa but still indicate smaller scale changes. A sensitivity analysis was also conducted to measure the reliability of our models and test specific uncertainties within the modeling process, as well as other uncertainties uncovered during analysis. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 302:794-817, 2019. © 2018 Wiley Periodicals, Inc. |
| Databáze: | OpenAIRE |
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