Increased sampling reveals the complex evolution of sauropod dinosaur tooth replacement rates.

Unlike most herbivores, sauropod dinosaurs evolved simple teeth that were replaced rapidly. Sauropod craniodental morphology is conserved relative to that of many archosaur clades, but tooth breadth and replacement rate vary substantially. Two neosauropod clades, Titanosauria and Diplodocoidea, independently evolved both narrow-crowned teeth and high tooth replacement rates among a suite of other convergent features.

Evolution of amniote dentine apposition rates.

In amniotes, daily rates of dentine formation in non-ever-growing teeth range from less than 1 to over 25 μm per day. The latter value has been suggested to represent the upper limit of odontoblast activity in non-ever-growing teeth, a hypothesis supported by the lack of scaling between dentine apposition rates and body mass in Dinosauria. To determine the correlates and potential controls of dentine apposition rate, we assembled a dataset of apposition rates, metabolic rates and body masses for 80 amniote taxa of diverse ecologies and diets.