Anthropomorphidae

a group of higher primates that, together with the family Hominidae, make up the superfamily Hominoidea. According to the most commonly used taxonomic system, the Anthropomorphidae include two families: Hylobatidae (gibbons) and Pongidae (orangutans, chimpanzees, and gorillas).

Gibbons are about 1 m tall when erect and weigh 4–12.5 kg. Orangutans and chimpanzees attain a height of 1.5 m, and gorillas 1.75 m and greater. Chimpanzees weigh 50–70 kg, and orangutans and gorillas up to 100–150 kg. Some male gorillas in captivity attain a weight of 180 kg or greater. Female orangutans, chimpanzees, and gorillas are smaller than their male counterparts.

Cheek pouches and a tail are absent, and ischial callosities are present only in gibbons. The arms are considerably longer than the legs. The brain is relatively large, with developed sulci and convolutions; it weighs 100–150 g in hylobatids and 350–600 g in pongids (sometimes to 750 g in gorillas). Male orangutans and gorillas have well-developed cranial crests. Orangutans have 12 pairs of ribs; all other species have 13 pairs. The animals have an appendix, which reaches a length of 20–25 m. Laryngeal sacs are well developed.

Chimpanzees and gorillas inhabit the tropical rain and mountain forests of Africa. Gibbons occur in Southeast Asia, including Malacca and Sumatra. Orangutans are found on Kalimantan and Sumatra. The animals live in small herds or family groups. Pongids build nests for the night, but gibbons sleep amid dense foliage midway up trees. The animals often swing through the trees using only their arms. They feed mostly on plant substances, occasionally eating birds’ eggs and young birds. Chimpanzees sometimes feed on ants and termites.

Reproduction is year-round. The gestation period is seven months for gibbons, 225 days for chimpanzees, 275 days for orangutans, and 250 to 290 days for gorillas. Usually there is a single offspring. Sexual maturity is reached by the age of seven to ten years. The life-span may reach 30 to 60 years.

In many anatomical and physiological respects, chimpanzees and gorillas are the animals most closely related to humans. Biochemical research has revealed a nearly 100-percent similarity of polypeptides in humans and chimpanzees. For this reason, the chimpanzee is widely used in medical and biological experiments.

Fossil Anthropomorphidae were widespread in the Miocene and Pliocene periods of the Old World. Dryopithecus, the parent form of all extant pongids and the predecessor of humans, descended from the Miocene Pliopithecus, ancestors of the gibbons.

Owing to their decreasing numbers, orangutans, dwarf chimpanzees, the mountain gorilla, and two gibbon species are protected and registered in the Red Data Book of the International Union for the Conservation of Nature and Natural Resources.