Evolution of Bipedality and Herbivory Among Triassic Dinosauromorphs

Note that this paper is in Japanese with an English version of the abstract.

Kubo, T. 2011. Evolution of bipedality and herbivory among Triassic dinosauromorphs. Memoir of the Fukui Prefectural Dinosaur Museum 10:55－62．

Abstract - Discoveries of Triassic non-dinosaur dinosauromorphs since 2000 revealed that they were more widely spread chronologically and geographically than previously thought. A member of silesaurids, the sister clade of dinosaurs, Silesaurus was a quadrupedal and herbivorous animal that differs considerably from the condition previously assumed for the ancestor of dinosaurs that are bipedal and carnivorous. Currently, stance and diet of the common ancestor of dinosaurs are not clear. To redeem this situation, Ancestral State Reconstruction methods were conducted to infer how quadrupedality and herbivory were evolved among dinosauromorphs. The results of analyses indicate that quadrupedal stance evolved only among silesaurids. Herbivorous diet was readily evolved from carnivorous diet among Dinosauromorpha and the ancestral state reconstruction using likelihood methods indicated that the possibility of the common ancestor of dinosaurs being herbivore is more than 60%.