. Scientists believe a whole range of questions about the human and dinosaur family trees could be answered by examining proteins remaining in preserved bones.
DNA is the best tool for examining our past – but DNA only survives in fossils less than around 100,000 years old.
But protein can be found in much earlier archaeology, and can help scientists build up a picture of what the DNA sequence might have been.
Researchers at York University have made it possible for an international team to extract and sequence protein from a 75,000-year-old Neanderthal fossil discovered in Shanidar Cave in Iraq.
They used the University's £500,000 protein mass spectrometer to investigate the remains: the oldest fossil protein ever sequenced.
It came from the "old man of Shanidar" – found at a human burial site excavated in the early 1960s by archaeologist Ralph Soleki. The bones were from a Neanderthal man, aged 45 to 50.
Biomolecular archaeologist Dr Matthew Collins played a leading role in the York research, which is now being continued in Germany.
Dr Collins said: "In trying to find out information about the human family tree, DNA is the most powerful tool we can use – but the problem with DNA is it is quite fragile and degrades."
Analysing the protein could reveal the DNA sequence because they both followed a similar pattern, he explained.
Dr Collins has been trying to perfect the technique since 1989, but research into human genes had now provided new technology, such as the scanner at York.
"We will be getting a lump of rock to give up its secrets. It is already known that caveman DNA is closer to ours than apes," he said.
"But we want to go back further. This protein might survive in dinosaur bones. It could establish if dinosaurs are related to birds or reptiles, and other big questions.
"We could find out what people ate, did they use diary cattle and milk cows, and what diseases were prevalent."
It could also help solve questions raised by blood stains on tools whether early men were hunter gatherers, or killed each other for food.