Sexual bimaturism describes a difference in developmental timing between males and females of the same species.
[1] Male simian primates are generally larger than females of the same species due in part to extended growth periods.
For example, male orangutans reach sexual maturity around age 15 but undergo an additional period of development later in life before they exhibit cheek flanges.
[4][5] The onset of this second developmental phase varies greatly and may be influenced by the proximity of other flanged males.
[6] In humans, sexual bimaturism is evident in that males begin puberty later than females.