The Tyrant Lizard King, Queen and Emperor: Multiple Lines of Morphological and Stratigraphic Evidence Support Subtle Evolution and Probable Speciation Within the North American Genus Tyrannosaurus

The Tyrant Lizard King, Queen and Emperor: Multiple Lines of Morphological and Stratigraphic Evidence Support Subtle Evolution and Probable Speciation Within the North American Genus Tyrannosaurus Abstract Introduction Variability Within Tyrannosaurus “rex” Competing Explanations and Predictions Materials and Methods Results Skeletal Robusticity is Consistent Within Specimens But is Not Correlated with Absolute Size and Presumed Maturation Tyrannosaurus Femoral Proportions Do Show Unusual Variation Gracile Subadults and Adults are Stratigraphically Limited Incisiform Dentary Tooth Arrangement Correlates with Femoral Robusticity and Also Appears to Change with Time Discussion Conclusion and Systematic Paleontology ZooBank Registration Acknowledgements References