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Allosaurus Body Mass:
BATES ET Al.

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Abstract

Introduction

Material and Methods

Results

Discussion

Conclusions

Acknowledgements

References

Appendix

 

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How Big Was 'Big Al'? Quantifying the effect of soft tissue and osteological unknowns on mass predictions for Allosaurus (Dinosauria:Theropoda)

ABSTRACT

MOR693, nicknamed 'Big Al,' is the most complete skeleton of the non-avian theropod Allosaurus and therefore provides the best opportunity to investigate the mass properties of this important Jurassic theropod through accurate physical or digital volumetric models. In this study, laser scanning and computer modelling software have been used to construct volumetric models of MOR693. A long-range laser scanner has been used to digitize the mounted cast of MOR693, allowing the reconstruction of body volumes and respiratory structures around and within the three-dimensional (3D) skeletal model. The digital medium offered the facility to modify model properties non-destructively in a detailed sensitivity analysis to quantify the effects of the many unknown parameters involved in such reconstructions. In addition to varying the volumes of body segments and respiratory structures, we also extend the sensitivity analysis to include uncertainties regarding osteological articulations in non-avian dinosaurs, including effects of inter-vertebral spacing and the orientation or 'flare' of the rib cage in MOR693. Results suggest body mass and inertial values are extremely uncertain and show a wide range in plausible values, whilst the CM (centre of mass) position is well constrained immediately in front and below the hip joint in MOR693, consistent with similar reconstructions of non-avian theropods.

Karl T. Bates. Adaptive Organismal Biology Research Group, Faculty of Life Sciences, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PL United Kingdom
Peter L. Falkingham. School of Earth, Atmospheric and Environmental Science, University of Manchester, Williamson Building, Oxford Road, Manchester, M13 9PL, United Kingdom
Brent H. Breithaupt. Geological Museum, University of Wyoming, Laramie, WY 82071, USA
David Hodgetts. School of Earth, Atmospheric and Environmental Science, University of Manchester, Williamson Building, Oxford Road, Manchester, M13 9PL, United Kingdom
William I. Sellers. Adaptive Organismal Biology Research Group, Faculty of Life Sciences, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PL United Kingdom
Phillip L. Manning. The Manchester Museum, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom, and School of Earth, Atmospheric and Environmental Science, University of Manchester, Williamson Building, Oxford Road, Manchester, M13 9PL, United Kingdom

Key words: Allosaurus; 'Big Al'; body mass; centre of mass; inertia; LiDAR; modeling

PE Article Number: 12.3.14A
Copyright: Palaeontological Association December 2009
Submission: 9 January 2009. Acceptance: 13 October 2009

 

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Allosaurus Body Mass
Plain-Language & Multilingual  Abstracts | Abstract | Introduction | Materials and Methods
Results | Discussion | Conclusions | Acknowledgements | References | Appendix
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