It may not be a Jurassic Park giant, but French scientists managed to resurrect a monster on the microbial scale: a virus which scurried about when mammoths and Neanderthals roamed the Earth. Now it's expected that the recently discovered giant virus may hold clues to how life was born on our planet.

A couple of years ago researchers grabbed some 32,000 year old frozen soil from 30 meters below Siberian tundra, let it thaw and watched in surprise as ancient viruses including Pithovirus sibericum came to life. And when it comes to viruses, Pithovirus sibericum is a true leviathan, measuring some 1.5 micrometers long, it is 50 times bigger than the common cold virus and even bigger than some bacteria.

And viruses aren't the only ancient forms we have been able to bring back to life.

In 2012, Russian scientists found buried in the same Siberian permafrost dozens of squirrel burrows filled with stashes of plant seeds from 30,000 years ago. One of these preserved seeds managed to actually grow and blossom. This ancient form of wild flower now represents the oldest revived plant, beating the previous record holder by 28,000 years.

Back in 2000, scientists managed to do the seemingly impossible and revive a 250-million-year-old bacteria from salt crystals buried more than 560 metres below ground in New Mexico.

But it's the handful of new giant virus species that has really caught the science community’s attention. What makes Pithovirus particularly interesting is that it is so different from other viruses in its ability to survive independently.

While most viruses take over their hosts' cellular machinery so that they can replicate, this giant has an unusually large number of its own DNA — 500 genes — about a hundred times more than its tinier cousins. This allows it to replicate on its own, opposite to what we've understood of these simple creatures.

Now some researchers are proposing that prehistoric ancestors to these giant viruses could very well have been the basic building blocks of more complex cellular life that evolved over billions of years.

“These giant viruses are the perfect example of how a world of simple viruslike elements could evolve into something much more complex,” said Eugene Koonin, a computational biologist who wrote a scientific paper on viral origin of life, in a recent interview with Quanta magazine.

The revived microbial giant from Siberia is still virulent but, fortunately, it only appears interested in infecting amoebas.

However, some biologists warn that, in the future, we might want to pay more attention to this resurrecting ability of ancient frozen life. As more and more of the the Arctic permafrost thaws due to warming temperatures and human exploitation, unknown ancient pathogens could on day be unknowingly released into the wild.

Could it pose a threat to today's wildlife and even humans?

The scientists who discovered Pithovirus fear just such a scenario and say that digging, mining and boring through ever deeper pristine soil could be a “recipe for disaster.” Potentially dangerous microbes currently thought to be eradicated and extinct may simply be lying dormant underground — just waiting to be awakened.