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A Fossil Guenon Monkey from the United Arab Emirates

Our team has just announced the discovery of a cheek tooth of a fossil monkey from the Al Gharbia region of Abu Dhabi Emirate, United Arab Emirates. This research is published today in the prestigious journal Proceedings of the National Academy of Sciences.

The fossil monkey tooth just moments after discovery. Shuwaihat, 2nd January 2009 (photo: Brian Kraatz).

The fossil monkey tooth just moments after discovery. Shuwaihat, 2nd January 2009 (photo: Brian Kraatz).

From anatomical comparisons, we determined that the UAE fossil monkey was related to  the ancestors of living guenon monkeys. Guenon monkeys are today known only from Africa south of the Sahara, and are especially diverse in the rain forests of Central and West Africa. Interestingly, guenons were only known from a scant fossil record as old as 4 million years ago, and only from Africa. Until now. At around 7 million years old, the Al Gharbia fossil monkey is the oldest guenon monkey known in the world, and the first record that guenons ever ranged outside of Africa.

The discovery of a fossil guenon monkey in the U.A.E. offers another reminder of how different Arabian climate and environments must have been 7 million years ago. The presence of rivers and woodland areas fits with our team’s previous discoveries of fossil hippopotamus, crocodiles, swamp rats, fish, turtles, and other water-loving animals and even fossil tree trunks in the Al Gharbia region.

The vervet monkey, a living guenon that is widespread in sub-Saharan Africa today (photo: Andrew Hill).

The vervet monkey, a living guenon that is widespread in sub-Saharan Africa today (photo: Andrew Hill).

The Al Gharbia fossil guenon is only the second specimen of a fossil monkey known from the entire Arabian Peninsula (the first is also from Al Gharbia but was less informative).

The fossil tooth is very small (just over half a centimeter in length) and was found by our team on the island of Shuwaihat. We were in the process of sieving through sands looking for tiny fossils such as rodent teeth and snake bones. We estimate the body mass of the Al Gharbia fossil monkey to have been between 4 and 6 Kg, which is similar to many guenons living today.

Our team sieving the sands for remains of tiny fossil animals. Shuwaihat, 2nd January 2009 (photo: Mark Beech).

Though it is only known from a single tooth, the Al Gharbia fossil guenon provides compelling evidence of the existence of these animals in Arabia in the past, far beyond their modern-day range. It also highlights that monkeys living seven million years ago had no problems dispersing between Africa and the Arabian Peninsula. This matches with the many fossil antelopes, hippos, crocodiles, rodents, giraffes, elephants, and carnivores that we have found in Al Gharbia to date that also indicate strong and continuous faunal connections with Africa.

CT scans of the fossil monkey tooth in different views. The tooth is just over half a centimeter long (photo: Christopher Gilbert).

Images of the fossil tooth in multiple angles. Scale bar = 5mm. Photo by E. Lazlo-Wasem.

Images of the fossil tooth in multiple angles. Scale bar = 1mm. (photo: Erik Lazo-Wasem)

Read the full press release here.

Abu Dhabi Authority for Tourism and Culture Arabic language press release here.

Reference: Christopher C. Gilbert, Faysal Bibi, Andrew Hill, and Mark J. Beech. 2014. Early guenon from the late Miocene Baynunah Formation, Abu Dhabi, with implications for cercopithecoid biogeography and evolution. Proceedings of the National Academy of Sciences, doi: 10.1073/pnas.1323888111

Two Review Papers on the Miocene Fossil Animals of Abu Dhabi

Our team has  published two  papers reviewing all the fossil species that we and previous teams have found from the Baynunah Formation of the Al Gharbiya region of Abu Dhabi Emirate.

The first is titled Before archaeology: life and environments in the Miocene of Abu Dhabi (pdf)from the book Fifty Years of Emirates Archaeology (editors D. Potts & P. Hellyer), published in 2012.

The second, also a book chapter, is titled Late Miocene Fossils from the Baynunah Formation, United Arab Emirates: Summary of a Decade of New Work (pdf), from a recently published book called Fossil Mammals of Asia (Columbia Univ. Press, editors X. Wang, M. Fortelius, L. Flynn).

In addition to providing information on the wide range of animals that existed in Abu Dhabi in the Late Miocene, these papers also review the history of discovery of fossils in the Al Gharbia region. The reviews (especially the second one) also compare the similarity of these  late Miocene fossil animals to those from Africa and Asia, showing that the region at the time housed a mix of African and southern Asian animals that is not recorded anywhere else.

To anyone previously unfamiliar with the subject, these reviews show quite clearly the diversity of prehistoric animals that used to live in this part of the Arabian Peninsula. This large diversity of everything from shells to crocodiles, rodents, birds, monkeys, and elephants was supported by a river system that once flowed through what is now the U.A.E., and that has long since gone dry and disappeared.

Excavating lower jaws of a proboscidean at the site of Hamra 3-1. To the south, in the background, are the upper beds of the Baynunah Formation. Taken on 17 December, 2007.

Excavating lower jaws of a proboscidean at the site of Hamra 3-1. To the south, in the background, are the upper beds of the Baynunah Formation. Taken on 17 December, 2007.

Map and satellite image of Al Gharbia showing main fossil localities. Black circles denote localities with body fossils, white circles denote fossil trackway sites.

Map and satellite image of Al Gharbia showing main fossil localities. Black circles denote localities with body fossils, white circles denote fossil trackway sites.

Stratigraphy and magnetostratigraphy of the Baynunah Formation. Body fossils (of vertebrates, invertebrates, and plants) are recovered from multiple horizons in the lower part of the Baynunah, while footprint fossils are recorded from carbonates correlating to the upper portion. Stratigraphic column reproduced from Ditchfield (1999, fig. 7.2), and paleomagnetic data from Hailwood and Whybrow (1999, fig. 8.5). The high frequency of polarity reversals in the period between 8 and 6Ma means any correlation of the Baynunah with the GPTS is equivocal, but the presence of at least 4 reversals in the Baynunah suggests a duration of 300,000 years or more for the Baynunah Formation.

Stratigraphy and magnetostratigraphy of the Baynunah Formation. Body fossils (of vertebrates, invertebrates, and plants) are recovered from multiple horizons in the lower part of the Baynunah, while footprint fossils are recorded from carbonates correlating to the upper portion. Stratigraphic column reproduced from Ditchfield (1999, fig. 7.2), and paleomagnetic data from Hailwood and Whybrow (1999, fig. 8.5). The high frequency of polarity reversals in the period between 8 and 6Ma means any correlation of the Baynunah with the GPTS is equivocal, but the presence of at least 4 reversals in the Baynunah suggests a duration of 300,000 years or more for the Baynunah Formation.

One of a herd of proboscidean (elephant) trackways at the site of Mleisa 1.

One of a herd of proboscidean (elephant) trackways at the site of Mleisa 1.