A primitive ancestor of some of nature's fiercest meat-eating beasts looked more like a nimble squirrel than today's lions, tigers and bears, according to scientists who have uncovered new fossils in Belgium.

The newly discovered species, known as Dormaalocyon latouri, is one of the earliest evolutionary links to modern carnivorous mammals and was a small furred creature that lived in the trees, researchers from the Royal Belgian Institute of Natural Sciences in Brussels said.

The fossil specimens recovered at the Belgian locality of Dormaal included more than 250 teeth and ankle bones.

The research was published in the most recent issue of the Journal of Vertebrate Paleontology.

The researchers believe the primitive-looking teeth of the Dormaalocyon date it back to around the origins of carnivorous mammals some 55 million years ago, during the beginning of the Eocene period.

Only weighed about 1 kilogram

According to the Belgian team, ankle bone samples indicate that Dormaalocyon were tree dwellers that lived in what was once a warm and humid environment in present-day Europe before migrating to North America during an extremely warm period known as the Paleocene-Eocene Thermal Maximum.

Image reconstructions show Dormaalocyon were small, with long tails. The researchers say the findings suggest present-day carnivores derived from Europe and that the Dormaalocyon would have weighed about 1 kilogram.

"The understanding of the origination of the carnivoraforms is important for reconstructing the adaptation of placental mammals to carnivorous diet," lead researcher Floréal Solé said in a press release.

"Therefore, Dormaalocyon provides information concerning the evolution of placental mammals after the disappearance of the largest dinosaurs."

Although researchers said the creature is very close to the origin of carnivorous mammals, they believe from examinations of fossils that there was an even earlier species in the group from a more primitive time.