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| The unique find belonged to a giant aquatic mammal that lived 37 million years ago Photo Credit: Maxim Sinitsa |
In the Sverdlovsk region, paleontologists have found the tooth of an ancient carnivorous whale that lived during the Eocene period (approximately 37 million years ago). This is the first such find, indicating that this animal lived in the Urals in ancient times. The unique find was discovered by Maxim Sinitsa, Associate professor of the UrFU Department of Biodiversity and Bioecology, during a joint expedition of the Ural-Siberian Society of Fossil Lovers public organization.
"We have been collecting fossils on the banks of the Tura River. The expedition included both volunteers and professional paleontologists from Ekaterinburg and Tyumen. We traveled to a well-known location, where Eocene deposits, about 37 million years old, are exposed for many kilometers. This time, hundreds of teeth and skeletal fragments of cartilaginous (rays, gray, otodus and sand tiger sharks of the genera striatolamia, yekelotodus, mennerotodus, physogaleus), bony fish (whiting, cod and tuna fish), as well as part of the shell of a turtle were found. But the main find is a well-preserved fragment of an ancient whale tooth from the extinct Basilosaurid family," says Maxim Sinitsa.
As the paleontologist explains, about 37 million years ago there was the northwestern tip of the huge inland Paratetis Sea, which united what is now the Black, Azov, and Caspian Seas, up to the Aral Sea. From west to east, the area from France to Altai was flooded with water, which formed a unique ecosystem. Ancient giant basilosaur whales swam in this sea, among others. They were aquatic super predators of their time and reached impressive sizes: the body length of adult males of the genus Basilosaurus exceeded 20 meters with a weight of 15-16 tons. However, there were no finds of ancient animals in the Urals.
"We found a cheek tooth. It's either a molar or a premolar. We can't say for sure yet whether it is upper or lower. We will clarify after studying it. Now we can say that the tooth belonged to a representative of the Basilosaurid family. This is an extensive family, in which more than 15 genera are distinguished. They are characterized by a long serpentine body up to 21 meters in length; the females were smaller, up to 18 meters in length. Most likely, they did not have very powerful deposits of fat, because they lived in much warmer conditions than, for example, modern whales. It was also found that, for example, they did not have echolocation organs in the form of a frontal fatty protrusion, which is located in the front of the skull of some modern toothed cetaceans," Maxim Sinitsa describes the ancient animal.
Judging by the structure of the teeth, the ancient whale was a predator, not a filter-feeder like most modern large whales.
"It was a primitive whale, with about 40 teeth in its long jaws. The front teeth in the jaw were identical, conical, and the back, cheek teeth, flattened, with several small tubercles. In fact, cutting and crushing," Maxim Sinitsa lists.
Scientists suggest that these whales had a very mobile spine. That is, they easily bent in the direction of the vertical plane, as many mammals swim, including humans or modern whales. But it is also possible that they had mobility in the horizontal plane, which modern cetaceans do not have, the paleontologist adds.
In addition, it is well established that these whales had hind limbs.
The scientists plan to transfer the tooth to the Paleontological Institute of the Russian Academy of Sciences in Moscow for study. As the scientist explains, there are very few specialists who study ancient cetaceans in Russia. There are no such people in Ekaterinburg. The main task of the Moscow colleagues will be to compare the Ural find with the teeth of other whales and find out its systematic position.
"It is possible that we have discovered a new species or genus. The fact is that there have been no finds of such a whale here. Despite the fact that whales migrate, there is a possibility that we have discovered an endemic form that lived only here, in the northeastern tip of Parathetis. Dental examination will help us find out," Maxim Sinitsa concludes.
Source/Credit: Ural Federal University | Delfina Zakharova
Reference Number: pal091625_01