The ontogeny of knuckle‐walking and dorsal metacarpal ridge prominence in chimpanzees

Abstract Objectives This study examines the sensitivity of development dorsal metacarpal ridge (DMR) to frequency knuckle‐walking during ontogeny in chimpanzees, and compares prevalence prominence DMR hominoids baboons. Materials Methods We characterized type quadrupedalism wild chimpanzees different ages from Ngogo community, Uganda. Using museum specimens, we quantified third angle height Pan individuals developmental stages, adult Gorilla , Pongo Hylobates Papio . Results When terrestrial, all consisted knuckle‐walking, although older knuckle‐walked more than younger. The total amount engaged by age groups while arboreal was consistent; however, knuckle usage arboreally quadrupedal increased with age. did not emerge until infancy, after onset reached juvenile stage. significantly juvenility but relative not. Adult have prevalent prominent DMRs ; rare absent Discussion timing supports it as a walking character, does its occurrence gorillas, virtual absence suspensory orangutans gibbons baboons differs appearance African apes, so differentiates digitigrady catarrhines. relationship between loading vertical hand terrestrial deserves further study.