Vascular system associated with the sidewall of the braincase and the prootic canals of cynodonts, including mammals

Abstract

The terminology of the cranial vascular system of cynodonts and early mammals is confusing and this confusion extends to certain associated features of the bones of the braincase. In the present paper it is attempted to clear up some of this confusion and to demonstrate that previous authors have unwittingly used the term ‘prootic canal’ to denote two entirely different structures. New evidence from the Tritylodontoidea allows useful speculation regarding the developmental origin of these ‘prootic canals', as well as the phylogeneticorigin of mammals.