Fossilized Giant Rhino Bone Questions Isolation Of Anatolia, 25 Million Years Ago

These results were obtained thanks to analyses of the first fossilized giant rhinocerotoid bone discovered in 2002² in an Anatolian deposit during a Franco-Turkish paleontology expedition funded by the ECLIPSE INSU-CNRS program. The presence of this bone in Anatolia, with the remains of associated fauna, are indicative of animal migrations between Europe and Asia. The results, published online in the March 2008 issue of the Zoological Journal of the Linnean Society, thus call into question the isolation of Anatolia, which until now was considered to have been an archipelago.

This is the first time that a fossilized giant rhinocerotoid bone dating from the Oligocene epoch (a period corresponding to intense tectonic movements around the Mediterranean Sea) has been found in Anatolia. Discovered in 2002 during a Franco-Turkish paleontology expedition in the region of ÇankiriÇorum (Central Anatolia, Turkey), the bone fragment³ from the forearm (radius) described by the scientists measures 1.20 meters long and probably belonged to a very large male (about 5 meters to the shoulder), attributed to the Paraceratherium genus.

These herbivorous animals, also called baluchitheres or indricotheres, are considered to have been the largest terrestrial mammals that ever existed, equal in size to the largest mammoths (with a height to the shoulder estimated to be 5 meters or more, and a body weight of 15 to 20 tons).
 
As well as this specimen of Paraceratherium, known to have existed notably in Pakistan, China, Mongolia and Kazakhstan, the remains of ruminants and rodents were also found in the deposit. They enabled dating of the specimen to about 25 million years, and also exhibited close affinities with contemporary fauna in Asia and/or Europe. This observation is particularly surprising in that Anatolia was until now considered to have been an archipelago at that time, separated from both Europe and Asia by what is referred to as the Paratethys Sea; the Black, Caspian and Aral seas are today the only remaining vestiges of this body of water.

The discovery thus proves the existence of terrestrial communication and close links at that period between Europe (including France) and Asia (China, Mongolia, Pakistan). Thus, during the Oligocene epoch, Anatolia was not isolated by the sea and was at least an isthmus: animals could therefore cross on dry land from continental Asia to Anatolia.
 
On the other hand, this discovery also tends to confirm that there was indeed a separation from Africa, as to date no species of African affinity has been found in the Oligocene soils of Anatolia.

Notes:
 
¹ A peninsula situated at the western tip of Asia, it now corresponds to the Asiatic part of Turkey (96% of the total Turkish landmass, the remaining 4% being situated in Thrace).
² In the region of Çankiri-Çorum (Central Anatolia, Turkey).
³ This is similar in size to the largest radius from a baluchithere known to date, a specimen discovered in Mongolia during the 1930s in strata dating from the same period (approximately 25 million years).
 
Reference: A giant rhinocerotoid (Mammalia, Perissodactyla) from the Late Oligocene of north-central Anatolia (Turkey). Zoological Journal of the Linnean Society, 152: 581-592.