Avian Theropods

Birds have been around for about 150 million years. Although birds and theropod dinosaurs have many characteristics in common, their relationship to each other has been hotly contested. They both possess a one way respiratory system, and (we now know) a similar sized genome. In a recent study, a Harvard University team was able to estimate the cell sizes and, consequently, the genome size of theropod dinosaurs. What they discovered is that theropod dinosaurs such as Tyrannosaurus rex and Velociraptor had a genome size in the range of modern birds, therefore establishing an evolutionary link between birds and Theropod dinosaurs.