055 -- Forelimb morphology and function of Raptorex kriegsteini (Dinosauria: Theropoda)

Raptorex kriegsteini is a bipedal species of predatory dinosaur that belongs to the clade Tyrannosauridae. A Raptorex skeleton 3 meters in length was discovered in the northeast region of China, and it was estimated to be a 5 or 6 year old adult. One of the unique morphological features of this taxon is the forearm. Similar to Tyrannosaurus rex, the forelimbs of Raptorex are very small in proportion to the rest of their body in comparison to those of other nonavian theropods. In order to investigate the potential function of the limb of this taxon, an analysis of the forelimb morphology was undertaken, including a reconstruction of the forelimb musculature in advance of creating a three-dimensional musculoskeletal model of the limb. Computerized tomography (CT) scans of the bones were used to create virtual 3D images of each element. A previous reconstruction of the forelimb musculature of Tyrannosaurus rex was used as a guide to determine the sites of muscle attachments on each part of the forelimb of Raptorex, and the locations for these attachment sites were marked on the virtual models using Adobe Photoshop. These muscle maps will be used in the next phase of this study, in which we will articulate the bones using Maya software to have a complete 3D model of the forelimb and begin adding virtual muscles to analyze the function of the forelimb.