>>8761528Crocodiliformes are archosaurs but Avemetatarsalia which unite dinosaurs/aves with pterosaurs and other dinosaurmorphs. Avemetatarsalia (bird ankle) do not have the crocodilian double jointed ankle. All True dinosaurs have an open acetabulum, an open hip joint the femur sockets into horizontally. Pterosaurs, and other dinosauromorphs have dinosaur ankles but retain the closed acetabulum. However there is evidence for dinofuzz in these dinosauromorphs (which are not crocodiles), which makes it likely all true dinosaurs have some form of dinofuzz. This may be lost later, especially in herbivores for whom a fast metabolism is less important, and who focus on other forms of defense, such as scutes and keratin structures.
