Fig. 4 in The Cross River Gorillas: A Distinct Subspecies, Gorilla gorilla diehli Matschie 1904

Fig. 4. Lateral views of ZMUB 12789 (A) and of the lone female paratype of G. diehli (Matschie 1904) ZMUB 12794 (B). The photograph shows the left side of ZMUB 12794 reversed for comparison. Note the strong concavity at the nasal bridge (especially in the female) and the inferior position of the mastoid relative to the external acoustic meatus. In the male the mastoid inflation is within the suboccipital plane, with only a very slight inferior protrusion. The development of the sagittal crest in the holotype is not characteristic of G. g. diehli males.