Zoology: Bones

Gibbons are structurally situated somewhere between the monkeys and the great apes, sharing some features of both. Siamangs and gibbons are now collectively called the "lesser apes" or "small apes." There is almost no sexual dimorphism in size or skull structure and gibbons (including the siamang) are the only apes that sit on ischial callosities. They have the longest arms proportional to their body size of all the primates and have many skeletal adaptations to better enable their canopy lifestyle. They primarily use a suspensory form of locomotion, known as brachiation, in which their body weight is more efficiently distributed beneath a tree branch by their arms and hands, like a pendulum. Gibbons live in small family groups rather than in larger social groups, as do the great apes. Adults usually remain paired for long periods. 2-part skull (separate cranium & jaw).

Conservation Status: Endangered

4" L x 2 ½" W x 3" H 10.2 cm x 6.4 cm x 7.6 cm