Tag Archives: Late Miocene

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

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‘Hummus Rat’ Discovered

Our team has just published the discovery and description of a large fossil cane rat from the Al Gharbia region of Abu Dhabi Emirate, U.A.E. Cane rats today are only known from two species living in Africa, so it is very interesting to know that they once roamed across parts of the Arabian Peninsula.

The fossil cane rat is around 7 million years old and comes from the Baynunah Formation which is a sequence of river-deposited sands that are exposed in the western region of Abu Dhabi Emirate.

We named the new fossil rodent Protohummus dango. The genus name Protohummus honors chick peas (Arabic: hummus) because the fossil teeth of this rodent were large, somewhat round, and stained yellowish-brown by the fossilization process, coming to resemble chick peas. The species name dango is from that of a local Emirati dish made of boiled chick peas.

From an evolutionary analysis, we concluded that Protohummus is a sort of ‘missing link’ in the evolution of the cane rat family (Thryonomyidae). Previous thryonomyid fossils were either already very similar to the living species, or else differed in many features. At 7 million years in age, Protohummus from Arabia fills an evolutionary gap between the thryonomyid Paraulacodus, an older, more conservative form known from Africa and Pakistan, and the living Thryonomys, known only from Africa.

The study was published in the scientific journal Naturwissenschaften. A pdf copy of the article is available here.

Here’s also a link to an article by The National newspaper about the discovery.

Study citation:

Kraatz, B. P., Bibi, F., and Hill, A., and Beech, M., 2013, A New Fossil Thryonomyid from the Late Miocene of the United Arab Emirates and the Origin of African Cane Rats. Naturwissenschaften. DOI 10.1007/s00114-013-1043-4

Can you spot the tooth of Protohummus? It’s the yellow-brown round thing in the middle of the plate. (image: F. Bibi CC BY-SA-NC)
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The living African cane rat. The new Arabian fossil cane rat Protohummus was just as large (image: A. Zizo wikimedia commons)
Sieving at SHU 2-6.
In order to find fossil rodents, we spent many weeks sieving through several tons of ancient river sands (image: F. Bibi CC BY-NC-SA)
Our evolutionary analysis ('A') shows the position of Protohummus among fossil and living cane rats. Tree 'B' below shows the evolution of cane rats over the last 17 million years. Protohummus is intermediate between ancient extinct cane rats (Paraulacodus) and living cane rates (Thryonomys).
Our evolutionary analysis (‘A’) shows the position of Protohummus among fossil and living cane rats.
Tree ‘B’ below shows the evolution of cane rats over the last 17 million years. Protohummus is intermediate between ancient extinct cane rats (Paraulacodus) and living cane rates (Thryonomys).
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After sieving, we have to search through the remaining bits of sand and stone to find fossils (image: CC BY-NC-SA F. Bibi)
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Scanning Electron Microscope (SEM) images of the fossil teeth of Protohummus.
Map of the Al Gharbiah region of Abu Dhabi Emirate showing sites where remains of Protohummus were found.
Map of the Al Gharbiah region of Abu Dhabi Emirate showing sites where remains of Protohummus were found.
Two teeth of Protohummus, ruler is in centimeters (and millimeters). Though they look small, these are large teeth for a rodent.
Two teeth of Protohummus, ruler is in centimeters (and millimeters). Though they look small, these are large teeth for a rodent (image: F. Bibi CC BY-SA-NC)
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dango