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.
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 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.
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.
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