The basicranium of fossil hominids as an indicator of their upper respiratory systems

This study investigates the use of the basicrania of fossil hominids as a guide to reconstructing their possible upper respiratory systems. As described previlosly (Laitman and Crelin, '76; Laitman et al., '78), the exocranial orientation of the basicrania of extant primates is related to the position of upper respiratory structures such as the larynx and pharynx. These relationships in living primates sugest that the basicranium of fossil hominids may provide an indicator of what their upper respiratory systems were like. Originals and casts of 14 fossil hominids were examied. The marked similarites in overall basicranial form between Sterkfontein 5 and extant pongids indicate that Sterkfontein had an upper respiratory system similar to that of extant great apes. The Classic European Neandertals show a range of basicranial, and thus potential upper respiratory, structure comparable to extant human children between 2 and 11 years of age. Cro‐Magnon, Steinheim, Předmostí, Broken Hill, and the more recent North African hominids, exhibit basicrania much more similar to those of adult or sub‐adult modern humans. Their upper respiratory systems probably did not differ considerably from that of present day adult humans. Our craniometric analysis has shown that it is statistically improbable for the basicrania, and by extrapolation, upper respiratory systems of certain Neandertals to fall within the range of modern adult or sub‐adult humans. There thus appar to be at least two different pathways taken in the evolution of man's upper respiratory system after a common pongid‐like stage exhibited by the australopithecines. One line appears to have terminated with the Clssical Neandertals. The other line, encompassing those hominids with basicrania and upper respiratory structure of more modern appearance, may have given rise to modern man.