Email Print Share

News Release 10-120

New Primate Fossil Found in Saudi Arabia

Researchers discover a new primate fossil suggesting the split between humans and Old World monkeys occurred 29 million years ago

Photo of the palate and upward-facing teeth of a 29-28 million year old primate fossil.

New primate fossil found in Saudi Arabia that lived 29-28 million years ago.

July 14, 2010

View a videoscan of the primate fossil.

This material is available primarily for archival purposes. Telephone numbers or other contact information may be out of date; please see current contact information at media contacts.

A new Catarrhine primate fossil discovered in Saudi Arabia suggests the evolutionary spilt between Old World monkeys and humans occurred older than previously thought, around 29 million years ago. The discovery challenges the theory that the groups diverged around 5 million years earlier than the date of the recent fossil find.

Geologist and paleontologist Iyad Zalmout and his colleagues from the University of Michigan and the Saudi Geological Survey reported the finding this week in the journal Nature.

Scientists long ago concluded humans and apes have a common ancestor with Old World monkeys, but it is unclear when the two groups diverged from that common ancestor. But the new catarrhine fossil, Saadanius hijazensis, found by Zalmout and his research team in western Saudi Arabia by the Red Sea is helping to shed light.

This is "the first substantial fossil primate from Arabia and from a period of between 30 and 23 million years ago where almost all the primate fossil record from this period is very rare, and if any is found, it is not as complete as this discovery," said Zalmout. The fossil, found in 2009, is dated to 29-28 million years ago. This discovery according to Zalmout emphasizes that "Afro-Arabia is the center of catarrhine origin and evolution."

The fossil preserves most of the face, the front upper part of the skull, the temporal bone and the palate, with some of the left and right upper teeth. By studying the length of the canine roots and the molar size, the researchers determined the fossil was an adult male and probably weighed 30-40 pounds.

Catarrhini is the name given to Old World apes and monkeys grouped collectively, and Saadanius is the most advanced primate known that has general catarrhine characteristics but still lacks the particular traits found in either apes or Old World monkeys.

Saadanius is intermediate in geological age and morphology between older and more primitive ape-like primates from Egypt, and later and more advanced apes and Old World monkeys from East Africa.

Since Saadanius hijazensis is dated 29-28 million years ago, this finding suggests that the split between Old World Monkeys and the line leading to humans occurred older than previously thought. Instead of 25-23 million years ago as originally thought by paleontologists, the split probably happened around 29 million years ago. This new geological evidence from the fossil record shows that molecular clock DNA estimates of an older divergence are not likely to be correct.

William Sanders, the second author on the paper, said, "This new primate gives researchers a better idea of the time of the divergence of Old World monkeys and apes, and a better knowledge about what the ancestor of Old World monkeys and apes looked like. This discovery also helps identify difficult-to-recognize early apes, which had few features of modern apes."

Principal investigator Philip Gingerich, University of Michigan professor of paleontology, adds that "the new primate was found while searching for geological strata that might yield fossil whales, which shows the importance of ongoing exploration in new areas." Richard Lane, program manager in NSF's earth sciences division, explained that the "discovery of Saadanius hijazensis is a side benefit of NSF supported research in non-hominid vertebrate paleontology. It emphasizes the need for strong field support in the historical geosciences."

This research was supported by the National Science Foundation and the Saudi Geological Survey.


Media Contacts
Kimberly J. Montgomery, NSF, (703) 292-8463, email:

Principal Investigators
Philip Gingerich, University of Michigan, 734-764-0490, email:

Iyad Zalmout, University of Michigan, 734-764-0489, email:
William Sanders, University of Michigan, 734-936-1380, email:

The U.S. National Science Foundation propels the nation forward by advancing fundamental research in all fields of science and engineering. NSF supports research and people by providing facilities, instruments and funding to support their ingenuity and sustain the U.S. as a global leader in research and innovation. With a fiscal year 2022 budget of $8.8 billion, NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and institutions. Each year, NSF receives more than 40,000 competitive proposals and makes about 11,000 new awards. Those awards include support for cooperative research with industry, Arctic and Antarctic research and operations, and U.S. participation in international scientific efforts.

mail icon Get News Updates by Email 

Connect with us online
NSF website:
NSF News:
For News Media:
Awards database:

Follow us on social
Twitter: and