Two theropod dinosaurs, Tyrannosaurus rex and Carnotaurus sastrei, antagonize one another with territorial roars deep in what will be known as the Amazon basin in South America 66 million years later. During the Late Cretaceous Period when these dinosaurs lived, North and South America were not connected by land yet. However, given that titanosaurian sauropods such as Alamosaurus are thought to have colonized North America from the south during this time period, perhaps by swimming across the sea, I wondered if the exchange of fauna could have gone the other way as well. Who knows, maybe we’ll uncover evidence of North American dinosaurs such as T. rex settling in the south someday.