The Study of Growth - An Invariant Approach to Statistical Analysis of Shapes - page 230

Figure 5.3. Immature (top left) and adult female (bottom left) skulls of Cebus apella with location of six facial landmarks used in
growth analysis indicated. Immature (top right) and adult female (bottom right) skulls of Macaca fascicularis are given in the
lower panel. Landmarks include: 1, NSL; 2, IDS; 3, PMM; 4, ZMS; 5, MXT; 6, PNS. The posterior spine is located on the sagittal
plane and cannot be seen from this view. Its location in this drawing is therefore approximate. Though both immature specimens
are from the same developmental age group, the immature M. fascicularis skull is of a younger age than the immature C. apella
skull, which accounts for the size difference in these immature specimens.