Ultramicrostructural reductions in teeth: implications for dietary transition from non-avian dinosaurs to birds

Ultramicrostructural reductions in teeth: implications for dietary transition from non-avian dinosaurs to birds

Blog Article

Abstract Background Tooth morphology within theropod dinosaurs has been extensively investigated and shows high disparity throughout the Cretaceous.Changes or diversification in feeding ecology, i.e.

, adoption of an herbivorous diet (e.g., granivorous), is proposed as a major driver Vinyl SODA of tooth evolution in Paraves (e.

g., Microraptor, troodontids and avialans).Here, we studied the microscopic features of paravian non-avian theropod and avialan teeth using high-spatial-resolution synchrotron transmission X-ray microscopy and scanning electron microscopy.

Results We show that avialan teeth are characterized by the presence of simple enamel structures and a lack of porous mantle dentin between the enamel and orthodentin.Reduced internal structures of teeth took place independently in Early Cretaceous birds and a Microraptor specimen, implying that shifts in diet in avialans from that of closely related dinosaurs may correlate with a shift in feeding ecology during the transition from Pull-Up Diapers non-avian dinosaurs to birds.Conclusion Different lines of evidence all suggest a large reduction in biting force affecting the evolution of teeth in the dinosaur-bird transition.

Changes in teeth microstructure and associated dietary shift may have contributed to the early evolutionary success of stemward birds in the shadow of other non-avian theropods.