Excavation of 'Jurassic beaver' in China

For a long time, the animals that lived with the dinosaurs were envisioned as tiny mice-like creatures, feasting on food under shrubs. Now, the new discovery of a hairy marine creature with teeth like a seal and a flat tail like a beaver has knocked out this image.

Castorocauda lutrasimilis is the largest known beast of Jurassic. It lived about 165 million years ago, during the Jurassic period, and is not a direct relative of the beaver today. ( AP )

About 164 million years ago, this newly discovered animal swam in lakes in northern China today, caught fish and shared the habitat with dinosaurs.

" Its lifestyles may be very similar to modern duckhounds," said Zhe-Xi Luo, curator of vertebrate archeology at the Carnegie Museum of Natural History in Pittsburgh. "He may have lived along rivers or lakes, kicked his flippers, ate insects and creatures in the lake, as well as dug for nesting ."

Luo's team from the Chinese Institute of Geological Sciences in Beijing found fossils of this creature in Inner Mongolia.

Thomas Martin, from the Senckenberg Research Institute in Frankfurt, Germany, said the discovery pushed the timeline of mammals into the water to the past over 100 million years. Because modern half-dry animals like otters, beavers and marine mammals like whales have not appeared until 55 - 25 million years ago.

It is important that the organism has been found to be highly specialized. " It provides evidence that primitive mammals are not only shadows in the period of dinosaurs, but are capable of self-evolution, " said Matthew Carrano, dinosaur manager at the National Museum of Natural History. Smithsonian, commented.

This is also the first evidence that some of the ancient mammals were semi-shallow half-life animals, indicating that biodiversity at that time was much greater than speculation.

The new animal found no relatives with modern beavers or otters, but bears many similar characteristics to them. That's why scientists named it Castorocauda lutrasimilis. Latin Castoro means beaver, cauda contains a tail, lutra means river otter and similis means similar.

Weighing from 500 to 750 grams, Castorocauda is also the largest known animal of Jurassic age.

T. An