Climbing into the saddle, he adjusts the scarf protecting his head from the sun and, with a tap on the camel's back, the caravan sets off.
Climbing into the saddle, he adjusts the scarf protecting his head from the sun and, with a tap on the camel's back, the caravan sets off.
Thierry Tillet is again off to explore the vast Saharan desert, at the head of a nine-camel convoy with three other riders.
At 68, the Frenchman is one of the last European explorers since the end of the 19th century to dedicate much of his life -- 47 years -- to crisscrossing the Sahara.
This expedition, which began before the coronavirus epidemic, starts and ends at two desert jewels in central Mauritania.
From Tichitt, the convoy is headed east to Oualata, 300 kilometres (185 miles) away, travelling in single file over a sandy, rocky landscape.
For the first time, Tillet -- or Ghabidine, as a Tuareg friend renamed him -- is taking journalists along "so that this knowledge reaches the general public".
Perched on the back of his swaying camel, Tillet wears an old, holey T-shirt and worn sandals.
With his tousled, white hair and stubbled chin, it's easy to forget he's an authority in his field.
For many years he was a member of the anthropology laboratory at France's National Centre for Scientific Research (CNRS).
He was also professor of prehistoric archaeology at Grenoble University and taught in Chad, Niger and Mali.
Throughout, he would go back and forth to the Sahara.
He has documented Neolithic civilisations, overseen the inventory of Malian archaeological sites and discovered a dinosaur skeleton in the Tenere desert in Niger.
"Sometimes, small fragments of discovered tools contain more information than a dinosaur, even if it's less spectacular," Tillet says.
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In All Its Diversity
Exploring the history of the world's largest expanse of arid land is a hugely diverse venture.
It can range from the forgotten religious centres of Sufi brotherhoods in northern Mali, to the sandstone plateaus in northeastern Chad and prehistoric Saharan settlements in Niger.
But trading his camel for the comfort of an air-conditioned vehicle as his mode of transport isn't an option for Tillet.
"You're going at the speed of the camel, and that allows me to observe and spot a number of things on the ground," he says.
"In a car I wouldn't be able to do that, it moves too quickly."
Each trip brings something new, be it publications in scientific works, "a few stones brought back for research" or photos of objects from the Neolithic era, the last period of the Stone Age.
Currently it's an 11th-century caravan depot lost in the Mauritanian dunes, the Ma'den Ijafen, that begs to be found.
"It was Theodore (Monod, the late French explorer) who discovered it in 1956," Tillet says.
"He asked me to go back there."
For three years now, he has been searching and, on this expedition, wants to ask around among nomadic shepherds.
Tillet does not consider himself an adventurer or a daredevil.
"Exploration carries with it a fantasy. I'm not trying to discover the unknown, but to discover what exists!" he says.
"That is true scientific exploration."
In this part of the Sahara, prehistoric artefacts are everywhere, constantly revealed by an omnipresent wind, but indistinguishable to the untrained eye.
"In a continental climate, it's often necessary to dig... Here, it's all on the surface."
Without warning, he pulls the reins to stop, on spotting something interesting.
If he doesn't know what it is, he takes notes and -- in his only recourse to 21st-century technology -- satellite coordinates using a GPS.
Once home in southwestern France's Perigord region, he will transfer them onto a map, tirelessly completing what he calls his "spider's web".
The hundreds of GPS points are not only a scientific record but suggest the route of his next expedition.