A Jurassic rat that lived 160 million years ago may have been the earliest known example of evolution’s most successful mammal, say scientists.

Rat-like multituberculates filled a multitude of ecological niches and survived on earth for more than 100 million years.

Eventually they were replaced by more modern rodents, but no other mammal has had such a long history in the fossil record.

The ancient creature, found in eastern China, had teeth adapted to eating both plants and animals, and highly rotatable ankle joints

The newly discovered species, Rugosodon eurasiaticus, is thought to be the oldest ancestor in the multituberculate family tree.

Despite living before the heyday of the dinosaurs, the creature already bore many of the features that made its descendants so successful.

The ancient creature, found in eastern China, had teeth adapted to eating both plants and animals, and highly rotatable ankle joints.

Zhe-Xi Luo, from the University of Chicago, US, a member of the American and Chinese team who describe the find in the journal Science, said: “The later multituberculates... are extremely functionally diverse. Some could jump, some could burrow, others could climb trees and many more lived on the ground. The tree-climbing multituberculates and the jumping multituberculates had the most interesting ankle bones, capable of ‘hyper-back-rotation’ of the hind feet.

“What is surprising about this discovery is that these ankle features were already present in Rugosodon, a land-dwelling mammal.”

The fossil’s teeth were very similar to those of late Jurassic multituberculates from Portugal, Luo added. This suggested that the animals spread themselves across the whole of Eurasia.

Rugosodon measured about 16.5cm, not including its tail, and would have been most active at night.

The location of the fossil bones suggests that the creature found by scientists lived on the shores of a lake.