“…These studies, however, have been carried out with diverse populations and using different protocols, which make the standardization of the results difficult (Knott, 1881;Okudera et al, 1994;Kobayashi et al, 2006). Sorting of the impressions left by the sinuses has been assessed by distinct methodologies (Dumont, 1894;Le Double, 1903;Mannu, 1907;Testut, 1911Testut, , 1921Edwards, 1931;Woodhall and Seeds, 1936;Browing, 1953;Browder and Kaplan, 1976;Dora and Zileli, 1980;Capra and Anderson, 1984;Bisaria, 1985;Durgun et al, 1993;Singh et al, 2004;Widjaja and Griffiths, 2004;Das et al, 2008), including (1) direct observation on the bone surface, (2) studying the sinuses in corpses, and (3) currently through in vivo magnetic resonance venographies. When dealing with fossil specimens, it is difficult to strictly follow one of these classifications of the sinus drainage pattern due to the fragmentary state of fossil skulls, as well as the fact that the cranial blood drainage has been described and classified following different standards.…”