121 - Forelimb musculoskeletal modeling of Tyrannosaurus rex (Dinosauria: Theropoda)

Tyrannosaurus rex is a bipedal species of predatory dinosaur that belongs to the family Tyrannosauridae. Tyrannosaurus rex is one of the largest theropod dinosaurs (approximately 12 meters in length) that ever existed and is well known for its forelimbs that were proportionally small for its size compared to those of other nonavian theropods. There is a lot of speculation about the function of the tyrannosaur forelimb, from use in prey capture to completely functionless, but it is unknown as to what they were actually used for. To better understand the potential function of the forelimb, three-dimensional (3D) musculoskeletal models are being created to investigate the potential movements and functions of the forelimb. Using computerized tomography (CT) scans of the forelimb bones, the arm was articulated using the 3D modeling software Maya and then transferred into OpenSim 4.4 where simplified muscles can be attached to the bone. Previous reconstructions of the forelimb musculature of Tyrannosaurus rex were used as a guide to determine the muscle attachment sites. Following the attachment of the virtual muscles, wrapping surfaces are being added to the model to give the muscles realistic and lifelike paths around the bones. Once the model is fully built and the muscle paths completely adjusted, it will then be used to test possible functions of the proportionally small forearm through analysis of the biomechanical properties of the different muscles.