Characteristics and origin of the human olfactory organ

The peculiar and characteristic structure of the human ethmoid is probably the result of 1) encephalisation and 2) insufficient adaptation to rapid evolution. In simiae only one ethmoturbinate is found, in man four or five. Due to posterior displacement of the lamina lateralis the turbinates compress each other, with overlapping, fusion, deformation and displacement, in highly constricted interorbital spaces.