Chu Mu and Tingyun chatted for a while longer.
The information Tingyun had was so outdated, and the geographical locations matched up so poorly, that very few of the leads were useful.
Back then, the Xianzhou researchers had surveyed the Sand Sea's human and physical geography.
At the time, the Sand Sea people had a tiny population and an extremely primitive civilization.
It was hard to imagine that, despite possessing normal human intelligence, the people here still lived in a primitive society with nothing but simple stone tools.
They had no proper tools, so they all lived in naturally formed caves.
The researchers had investigated the caves in detail and discovered textures resembling tree bark on their inner walls.
After mapping the caves in their entirety, they had been astonished to discover that the caves resembled enormous trees!
At the center of each tribe, the enormous sinkhole that plunged straight down was the trunk, while the horizontal caves were the branches.
The deep pits submerged beneath underground rivers were the trees' root systems.
Tribes like these, large and small, were scattered across the entire Sand Sea Planet.
All these signs suggested that the Sand Sea had once been covered in giant trees. Some upheaval had buried them beneath the sand, creating enormous underground caverns.
Chu Mu betrayed nothing as he listened.
In his own Blaze Tribe, the introduction of iron tools meant the original cave structure had long since been dug beyond recognition. Beneath the Pyramid, however, there was indeed a sinkhole that plunged straight down.
The Blaze Tribe now had tens of thousands of people. Yet in the survey a hundred years ago, the largest tribe the researchers had found numbered only around a hundred.
Back then, the Sand Sea people had subsisted on mushrooms grown from underground fungi,