Sivapithecus, fossil primate genus dating from the Miocene Epoch (23.7 to 5.3 million years ago) and thought to be the direct ancestor of the orangutan. Sivapithecus is closely related to Ramapithecus, and fossils of the two primates have often been recovered from the same deposits in the Siwālik Hills of northern Pakistan.
Time-period
It belongs to Miocene epoch and various specimens are found between 12.5-8.5 million years ago
Geographical distribution
Siwalik region of Pakistan . Other Sivapithecus remains have been found at sites in Turkey, Pakistan, China, Greece, and Kenya.
Archaeologists
In 1982, David Pilbeam published a description of a significant fossil find, formed by a large part of the face and jaw of a Sivapithecus. The specimen bore many similarities to the orangutan skull and strengthened the theory (previously suggested by others) that Sivapithecus was closely related to orangutans.
Features
The cranial morphology of at least one specimen of Sivapithecus clearly shows its relation to living orangutans.
- Sivapithecus was about 1.5 metres (4.9 ft) in body length, similar in size to a modern orangutan.
- A concave face markedly upward in profile.
- Eyes set narrowly apart
- The orbits are shaped like elongated ovals, tall from top to bottom, and with a similar orientation of the tear ducts in the inner corners of the orbits.
- A smooth nasal floor
- Large zygomatic bones
- Enlarged central incisors, large canine teeth, and heavy molars, suggesting a diet of relatively tough food, such as seeds and savannah grasses.
All these features show similarities to the features of orangutan. However, there are dental differences between Sivapithecus and living orangutans. Both apes have thick molar enamel, but in orangutans, the enamel of orangutans is wrinkled into complicated tooth surfaces. In contrast, the surfaces of Sivapithecus teeth are uncomplicated and similar in form to Dryopithecus. This primitive molar form is also similar to early hominids, and some of the earliest-known specimens of Sivapithecus were once believed by many paleoanthropologists to be hominid ancestors.
Species
- Sivapithecus indicus
- Sivapithecus sivalensis
- Sivapithecus parvada
Phylogenetic position
Earlier Sivapithecus along with Ramapithecus we thought to be possible first step in the evolutionary divergence of humans from the common hominoid stock of the apes. However, later specimens and reinterpretation of all fossils led to the opinion that they are the ancestral forms of modern day orangutan.