Length-width ratios of the presphenoid and basisphenoids shown across ages in subadult lemurs (Lemur catta) and tamarins (Saguinus spp.). The fetal to newborn data are from Saguinus geoffroyi, whereas the newborn to infant data are from Saguinus oedipus. Because the data are from two different species; there is some discrepancy between newborn data points for the presphenoid (by chance, this is not the case for the basisphenoid). The presphenoid stands out as a segment that is elongated (higher length-width ratio) compared to the basisphenoid; these preliminary data indicate this may be a proportional change during later fetal development