Below is a cladogram with extinct species. Hominoidea are thought to have evolved in Africa by about 18 million years ago. Among the genera thought to be in the ape lineage leading up to the emergence of the great apes about 13 million years ago are Proconsul, Rangwapithecus, Dendropithecus, Nacholapithecus, Equatorius, Afropithecus and Kenyapithecus, all from East Africa. During the early Miocene, Europe and Africa were connected by land bridges over the Tethys Sea. Apes show up in Europe in the fossil record beginning 17 million years ago. Great apes show up in the fossil record in Europe and Asia beginning about 12 million years ago. The only living great ape in Asia is the orangutan. Various genera of dryopithecines have been identified and are classified as an extinct sister clade of the Homininae. Dryopithecines was first uncovered in France and it had a large frontal sinus which ties it to the African great apes. Orangutans which are only found in Asia do not. They did have thick dental enamel another ape-like characteristic. The study of Dryopithecini as an outgroup to Hominidae suggests a date earlier than 8 million years ago for the Homininae-Ponginae split. It also suggests that the Homininae group evolved in Africa or Western Eurasia, against the theory that Homininae were originally an Asian line which later recolonized Africa after the Great Apes went extinct in Africa. During the later Miocene the climate in Europe started to change as the Himalayas were rising and European became cooler and drier. About 9.5 million years ago tropical forest in Europe was replaced by woodlands which were less suitable for great apes and European Homininae appear to have migrated back to Africa where they would have diverged into Gorillini and Hominini.
Appearance and ecology
The orangutan–human last common ancestor was tailless, and had a broad flat rib cage. The orangutan–human last common ancestor had a larger body size, larger brain, and in females, the canine teeth had started to shrink like their descendants. Great apes have sweat glands in their armpit versus in their chest like lesser monkeys. Orangutans have anterior lingual glands and sparse terminal hair like the hominines. Terminal hairs are those hairs that are easy to see. As compared to the tiny light colored hairs called Vellus hairs. Certainly there is some correlation with the size of the mammal. The larger the mammal the fewer terminal hairs. Near the tip of the tongue on the underside are the submandibular glands which secrete amylase. These are only found in the great apes so it is understood that the last common ancestor would also have these. With regard to the skull this is an example where humans share more in common with orangutans than with later great apes. We have two small ridges, one over each eye called superciliary arches. The great apes other than humans and orangutans have brow ridges.
