A lost race of humans arrived in Europe more than 45,000 years ago before mysteriously dying out, leaving no descendants, a new genetic study shows.

The oldest DNA ever recovered from modern humans shows that several small groups left Africa but are not related to anyone alive today.

Experts are unsure what happened to them, but believe a huge volcanic eruption in Italy around 40,000 years ago may have covered Europe in a choking cloud of ash, causing human and animal extinctions.

The early pioneering Europeans numbered just a few hundred and had dark skin, dark hair and brown eyes, reflecting their recent arrival from Africa.

DNA from bones found in Ranis, Germany, revealed some of the individuals were close relatives - including a mother and daughter - the first time a direct relationship has been found in the remains of ancient humans.

The family group was also found to be related to a woman discovered 150 miles away in the Koneprusy Caves, in the Czech Republic, who was likely a distant cousin or great-great-grandmother.

"These results provide us with a deeper understanding of the earliest pioneers that settled in Europe," says Johannes Krause, senior author of the study.

"These are the oldest genomes we have of modern humans. They represent a genetic lineage that has no descendants, that later all went extinct.

"We can also show that the population size of this group of early modern humans was rather small, only about 200 humans which is extremely low given the range, from the UK to Poland.

"It seems that all human lineages that were present in Europe at the time, including Neanderthals, went extinct about 40,000 years ago, so they didn't contribute to later people which is a bit of a mystery."

The genetic data was also able to show that the lost race had bred with Neanderthals between 45,000 and 49,000 years ago, sharing the same gene changes from the mixing as modern humans today.

But after moving to Europe, their DNA showed there was no more mixing between the species.

Dr Geoff Smith, a zooarchaeologist from the University of Reading, said: "These DNA results are exciting because they show differences in how frequently various groups of early modern humans met with Neanderthals.

"It is fascinating how these early modern humans were able to adapt to extreme cold conditions but were ultimately unsuccessful and died out."

Experts said that the second wave of modern humans who came out of Africa might have carried a genetic secret weapon that made them better able to adapt to new environments.

Dr Krause added: "The first thing they do is move to the glaciers and hunt mammoths, they also go to Oceania, they cross open water which was never done by any other human before.

"It made me always believe that they had... some combination of genes that gave them some sort of adaptability that wasn't there before.

"This is not just chance. There is some sort of package they have, and it's the story of why we are eight billion people on the planet."

The research papers were published in the journals Science and Nature.