Late Cretaceous dinosaurs and crocodyliforms from Egypt and Argentina
Although the Cretaceous continental tetrapod record of Gondwanan landmasses remains inadequately characterized, recent paleontological efforts have begun to improve this situation. This dissertation describes several new dinosaurian and crocodyliform discoveries from Late Cretaceous sediments of the Egyptian Sahara and central Patagonia, Argentina. Chapter 1 provides a brief overview of the two research projects responsible for these discoveries, the Bahariya Dinosaur Project and the Universidad Nacional de la Patagonia San Juan Bosco/University of Pennsylvania Patagonian Dinosaur Project. Chapter 2 presents a detailed study of the anatomy, evolutionary relationships, and body size of the gigantic titanosaurian sauropod dinosaur Paralititan stromeri from the early Late Cretaceous Bahariya Formation of the Bahariya Oasis, Egypt. Chapter 3 describes two new partial skeletons of the enigmatic theropod dinosaur Megaraptor from the early Late Cretaceous Bajo Barreal Formation of southern Chubut Province in central Patagonia, and provides unprecedented insight into the phylogenetic affinities of this taxon. Chapter 4 demonstrates that a purported ornithischian dinosaur humerus from the latest Cretaceous Quseir Formation of the Kharga Oasis, Egypt actually pertains to a dyrosaurid crocodyliform. This discovery restricts African ornithischian body fossils to pre-latest Cretaceous sediments.