Martin Brasier is a time traveller employed by Oxford University. Over the course of his career as a palaeobiologist, he has gone back two to three billion years, travelling to inhospitable places and facing sometimes hostile people – all without leaving planet earth or his own life-time.

Fascinated by the Precambrian era, which covers 80 per cent of earth’s history, his time-travel instruments are hammers and microscopes and his pathway to the past is through the hearts of rocks and their fossil records.

But where Dr Who has a Tardis, Prof Brasier has a small office next to Oxford’s Natural History Museum, piled high with bookshelves and drawers of all shapes and sizes. These hold slices of rock that spiral you out in space and time. Brought back from inhospitable parts of the world, they are evidence of earth’s earliest life forms.

Looking at one of his rock slices through a microscope, suddenly you’re seeing a tiny life form that existed two billion years ago. It is a heady, awesome moment.

At 62, he has experienced a lot of these moments. He has encapsulated some of them into Darwin’s Lost World: The Hidden History of Animal Life, the first in a trilogy about his search for Precambrian life.

The title refers to Darwin’s dilemma: why were there there no fossils before the Cambrian trilobites and other animal fossils? Where were their ancestors? It was believed that all evidence had been destroyed during the great “Cambrian explosion” of life between 544 and 505 million years ago.

From the book, we learn that Precambrian fossils were there all along and that paradoxically the fossil record gets clearer the further back in time you go. “The preservational quality gets better,” he explained. It’s not that they weren’t seen before, it’s just that they weren’t recognised.” That began to occur when Martin was at school in 1954 aged seven.

“We had to sit and listen to a BBC programme for children,” he said. A reporter would pretend to go back in a time machine to the remotest period. Martin had to write an essay on each broadcast.

“We did the Cambrian through to the Silurian, then the Devonian and early Carboniferous and earliest land animals and then dinosaurs and hominids. It was an extraordinary thing to do, back at that time.”

He noticed even then that the Precambrian period was not mentioned, which piqued his interest. He ended up studying geology.

“It combined biology and archaeology; stuff in the ground and life itself,” he said.

He fell “head over heels in love” with igneous rocks and knew at the end of his three years that he wanted to look at the earliest time periods.

The description of his discoveries is interwoven with anecdotes about life out in the field. His memory is so good because he has kept field journals and diaries for years. They are certainly not all about geology. Food gets a mention too. The worst meal he ever ate was in Outer Mongolia, where ‘fricassee of lamb’s anal sphincter’ put him off eating lamb for two years. You may not understand every (or even any) geological term, but nevertheless his tale is enthralling. This is not just an amazing story about our earth history, but also about Martin’s career and how much the Cold War impacted on it, particularly during the 1970s.

He said: “It wasn’t that surprising. I knew that the best rocks tended to lie behind the Iron Curtain and they were therefore playing that for all they could get.” He tells of a week’s conference where Russian discoveries were trumped by the Chinese, which didn’t go down well.

Martin has been at Oxford University since 1988 and loves the place. “I like the freedom to think outside the box, the strong intellectual atmosphere, the philosophical atmosphere and the traditions of scholarship and exploration at the frontiers,” he said.

He also loves his students, whom he describes as clever, open-minded and curious. “They’re just such fun to work with,” he said. He is hoping that after he has retired in a few years’ time, his collection of books, papers and fossils will be kept together. “It is one of the best in the world for studying Precambrian life,” he said. Meanwhile, he loves showing his fossils to new students.

“You can actually see them tremble,” he said. “They’re so excited at being in a room where it all comes together and they’re allowed to touch things and look at them.”

* Darwin’s Lost World is published by Oxford University Press at £16.99.