Add to favorite
 
123
Subscribe to our Newsletters Subscribe to our Newsletters Get Daily Updates RSS


120 Million Years of Chewing
September 26, 2006 17:32


Russian paleontologists have studied the upper molar tooth structure of the Kielantherium mammal, which had lived in the early Cretaceous period and have made an interesting conclusion – this animal was one of the first mammals, who learned to chew food. The tooth structure is still very primitive, thus scientists can certainly announce the discovery of an intermediate stage between “biting” and “chewing” mammals. The unique finding of the Russian scientists is described in the Science journal and allows making essential corrections in the early mammalian evolution theory.

Many humans start thinking about their teeth only after they visit their dentist or after they see the toothpaste ad for thousand times. But paleontologists consider teeth structure and animal dentition to be very important. These parameters not only help to identify an animal, they also give information on its way of life, its parents and descendants, its history and evolution. Moreover, teeth are sometimes the only things, describing terrestrial mammals, which are found during the diggings.

Animal dentition shows that while first mammals could only bite food and swallow it, their descendants have thoroughly chewed food before swallowing. This habit appeared to be useful, because it raised food efficiency. How did animals learn to chew? They had to invent upper and lower molar teeth - first serve as pestle and others – like mortar. Mammals have come a long way, before such system appeared – who was the first to use the chewing technology? Scientists have recently found possible candidate for the breakthrough.

The animal was found in stores of the Institute of Paleontology, where it has spent not less than 30 years – the remains of the upper molar tooth of the Kielantherium mammal, found in the lower Cretaceous deposits (100-120 million years old) in the Gobi desert. Russian scientists from Moscow and Saint Petersburg have found the remains, and described them in the famous Science journal. The research fellows think that Kielantherium belonged to the mammalian group, which was first to start chewing food – one molar tooth appeared to be enough for making corrections in the mammalian evolution theory.

Previous evolution theory suggested following hypothesis – Kielantherium‘s relatives were thought to be ancestors of marsupial mammals, and placental mammals were considered to separate from this branch earlier. However, Kielantherium's molar tooth showed some resemblance with teeth of placental mammals – it appears that chewing ability was formed in the early Cretaceous period in some common ancestor of both marsupial and placental mammals, and their separate evolution have started later. This theory can cause some hard and serious work on correcting the mammalian phylogenetic tree.

Sources:

Alexey V. Lopatin, Alexander O. Averianov. An Aegialodontid upper molar and the evolution of mammal dentition // Science, 2006, vol. 313, p. 1092.
www.elementy.ru
 

Anna Kizilova

 


Tags: Russian scientists Russian science    

Next Previous

You might also find interesting:

Expedition Reconstructs Ancient Landscape of Novaya Zemlya Archipelago Evil Creatures Threaten Invertebrates Arctic Expedition On Spitzbergen New Antibiotics to be Obtained from Siberian Plants in Tomsk New Understanding Of Black Holes









Comment on our site


RSS   twitter      submit



TAGS:
buy Russian designers  Exhibitions in Moscow  the Urals region  Russian tourism  Alexander Dymnikov  Mercedes-Benz Fashion Week Russia  Russian economy  Valery Gergiev  Parliament in Action  Voronezh   All Russia People's Front  adventure tourism  Russian business  Suzdal Museums  Internet in Russia  Ural   Russian theatres  Adler  Sports  Linkin Park  St. Petersburg  Innovations  Russian IT companies  Liski  All-inclusive  Best City in the World  Victory Day  Moscow  Zenit St. Petersburg  Russian science  Rostov Bazaar  Russian parks  Russian Railways  Karelia   Commercial Space Flights  Smolensk  VAT  Aleksandr Mamut  Censorship  Pushking Fine Arts Museum  Russian scientists  LGBT in Russia  Russian Cinema  Treasures  Silk Screening  Forest of Victory  Leningrad Oblast  Red Square  skiing in Russia  Russian designers 


Travel Blogs
Top Traveling Sites