The hypothesis that birds (avialans) are the living descendents of theropod dinosaurs like Velociraptor is now supported by a plethora of fossil evidence. From anatomical data, like the presence of furculae, pygosytles, and feathers in theropods, to behavioral data like dinosaurs found in brooding postures over nests of eggs, to the hypothesized presence of specialized soft tissues including beta keratin, medullary bone, and even collagen, the signal is increasingly clear. However, it is also clear that in a number of ways, birds are unique. The complicated evolutionary mosaic that resulted in the specialized morphologies, physiologies, and behaviors of modern birds remains poorly understood. Modern birds are among the fastest growers are on the planet, and the evolution of their extremely rapid growth rates is an important piece of the physiological evolutionary puzzle. My colleagues and I utilize bone histological tools and scaling principles in derived theropods and basal birds to address the following key questions:
Did birds inherit their extremely rapid growth rates from the dinosaur ancestors?
If birds uniquely derived their rapid growth rates, what was the pattern of change occur?
What are the growth rates of the dinosaurs most closely related to birds?