John R. Hutchinson; Karl T. Bates; Julia Molnar; Vivian Allen; Peter J. Makovicky
A Computational Analysis of Limb and Body Dimensions in Tyrannosaurus rex with Implications for Locomotion, Ontogeny, and Growth
Figure 1. Modelling procedureı showing the Carnegie specimen. From left to rightı top to bottom these show the scannedı reconstructedı and straightened skeleton; the skeleton with elliptical hoops that define fleshy boundaries; the air spaces representing pharynxı sinusesı lungs and other airways including air sacs; and the final meshed reconstruction used for mass and COM estimates. doi:10.1371/journal.pone.0026037.g001
Figure 2. Models: cranial view. From left to right for each specimen: 3D scan of skeleton (not shown for Jane due to copyright issues)ı minimal modelı and maximal model. Not to scale. doi:10.1371/journal.pone.0026037.g002
Figure 3. Models: right lateral view. See Figure 2ı but skeleton scans/models are ordered from top to bottom. doi:10.1371/journal.pone.0026037.g003
Figure 4. Models: dorsal view. See Figures 2ı3. doi:10.1371/journal.pone.0026037.g004
Figure 5. Muscle mass reconstruction method for M. caudofemoralis longus (see Methods); Carnegie specimen depicted. Dorsal and right lateral views are shown on topı and in the bottom row are caudal views of the right femur and then caudal vertebrae (8th and 17th). Red shaded volumes are the M. caudofemoralis longus reconstruction. Note a small space for M. caudofemoralis brevis (not reconstructed) is left around the ilium/sacrum and lateral to the CFL insertion. doi:10.1371/journal.pone.0026037.g005
Figure 6. Adjusted growth curve (mass in kg as a function of age in years) for Tyrannosaurus rex. Filled circles represent our mass estimates derived from digital modelling; squares represent data points generated using Developmental Mass Extrapolation [42]. The red line represents the best fit curve for modelled data; the black one is for the DME estimate. Stippled lines represent the 95% confidence intervals for the model-based estimates. The MOR specimen is treated as being 16 years old in this plot (see text). doi:10.1371/journal.pone.0026037.g006
Figure 7. Comparison of torso/body dimensions for the four large Tyrannosaurus rex specimens. Linear measurements from our digital models show how the gleno-acetabular distance (GAD) is anomalously short in the MOR specimen and the chest is anomalously wider in the Sue and Carnegie specimens. Otherwise all four specimens compare fairly wellı considering that the Sue specimen is known to be somewhat larger. doi:10.1371/journal.pone.0026037.g007