Bony cranial ornamentation linked to rapid evolution of gigantic theropod dinosaurs

Abstract

Many of the theropod dinosaurs, the group including Tyrannosaurus rex, had bony ornamentation on their skulls. Here, Gates et al. show that such ornaments are associated with greater body size and accelerated body size evolution in theropods; however, these relationships are absent in the maniraptoriform dinosaurs, which had evolved pennaceous feathers.