The first incomplete specimens of
Sivapithecus were found in northern India in the late 19th century. Another find was made in
Nepal on the bank of the
Tinau River situated in
Palpa District; a western part of the country in 1932. This find was named "
Ramapithecus". The discoverer, G. Edward Lewis, claimed that it was distinct from
Sivapithecus, as the jaw was more like a human's than any other fossil ape then known, a claim revived in the 1960s. At that time, it was believed that the ancestors of humans had diverged from other apes 14 million years ago. Biochemical studies upset this view, suggesting that there was an early split between
orangutan ancestors and the common ancestors of
chimpanzees,
gorillas and
humans. .|252x252px Meanwhile, more complete specimens of
Ramapithecus were found in 1975 and 1976, which showed that it was less human-like than had been thought. It began to look more and more like
Sivapithecus, meaning that the older name must take priority. It is also possible that fossils assigned to
Ramapithecus belonged to the female form of
Sivapithecus. They were definitely members of the same genus. It is also likely that they were already separate from the common ancestor of
chimpanzees,
gorillas and humans, which may be represented by the prehistoric
great ape Nakalipithecus nakayamai. Siwalik specimens once assigned to the genus
Ramapithecus are now considered by most researchers to belong to one or more species of
Sivapithecus.
Ramapithecus is no longer regarded as a likely ancestor of humans. In 1982,
David Pilbeam published a description of a significant fossil find from
Potwar Plateau,
Pakistan, formed by a large part of the face and jaw of a
Sivapithecus. The partial skull was likely scavenged after death. The specimen (GSP 15000) bore many similarities to the
orangutan skull and strengthened the theory (previously suggested by others) that
Sivapithecus was closely related to orangutans. In 2011, a 10.8 million-year old (
Neogene period) upper jawbone of
Sivapithecus was found in
Kutch district of
Gujarat, India. The find also extended
Sivapithecus' southern range in Indian subcontinent significantly. The species can not be identified. ==Description==