Scientists are racing to trace deep ocean species before they are lost, with the help of photographers who have a taste for danger.

In 2010 four friends, carrying 32kg (71lb) worth of camera equipment, sunk beneath the waves of Sodwana Bay, off the east coast of South Africa. It was then that photographer, Laurent Ballesta stared directly into the eyes of a creature once thought to have died out with the dinosaurs – and took the first ever photograph of a living coelacanth.

“It’s not just a fish we thought was extinct,” says Ballesta. “It’s a masterpiece in the history of evolution.”

Venture back to the beginning of the age of the dinosaurs, and you’d find coelacanths in abundance, on every continent, living in the steamy marshes of the Triassic Period. Dating back 410 million years, the coelacanth belongs to the group of “lobe-finned” fish that left the ocean between about 390 and 360 million years ago. Its strong, fleshy fins were a precursor to the paired limbs of tetrapods, which include all land-living vertebrates – amphibians, reptiles, birds and mammals and, yes, humans too. In fact, coelacanths are more closely related to tetrapods than to any other known fish species.