Lu Yuan looked at the petroglyphs in front of him and speculated in his heart.

These petroglyphs include fish, deer, goats, cows, hippos and mammoths.

These things show that ancient humans who originally lived here once carried out large-scale hunting activities.

And to be able to support large-scale hunting activities, the scale of this tribe is not too small.

And judging from the animals they hunted, this area was still a place with abundant water and grass and a lot of flora and fauna at that time.

This is also the reason why Lu Yuan speculated that the history of these petroglyphs was at least 2.5 million years old.

It's a pity that Lu Yuan doesn't have the testing equipment in his hands now, and it would be nice if he could test these fossils immediately.

If the age of these fossils can be confirmed, it will be easier to judge.

Now Lu Yuan can only be inferred from petroglyphs.

Lu Yuan continued to observe the petroglyphs, and soon he found some patterns depicting fire.

This information is very important for archaeology, which means that the tribe has learned to use fire.

Whether or not fire will be used in the study of civilization by historians is a sign of whether a tribe has entered civilization.

Through all the information revealed on the petroglyphs, Lu Yuan believed that this tribe had initially entered civilization.

And judging from the types of animals they hunt, they also have a relatively large range of activities.

It was supposed to be a very powerful tribe for its time.

With such a powerful tribe, this cave in front of them is obviously not able to accommodate them.

Lu Yuan judged that there must be a larger settlement area near this cave.

Lu Yuan had set up a situation in the cave, and he planned to stay in this place for a while.

In his opinion, the value of this place is so great that it can even change the whole world's understanding of the history of human development.

Although Lu Yuan had long known from the mouth of the intelligent housekeeper, human beings had actually experienced 5 civilizations.

But these things cannot be announced to the public, and even if Lu Yuan announces these news to the public, few people will believe it.

Just like there are many people in modern society who do not believe that the earth is round.

These people are not indigenous people living in the jungle, but inhabitants of developed countries.

In the United States alone, there are millions of inhabitants who believe that the earth is a disk.

They also formed an association with more than 400,000 full members.

Faced with something that is already recognized, and there are countless satellite images to prove it, there are so many people who choose not to believe it.

What's more, it's not easy for others to recognize this kind of thing in the history of human development.

Not to mention anything else, just like the Xia Dynasty of Zhuxia, there is already enough evidence to prove its real existence, and there are still many people who don't admit it!

Moreover, among these people who deny the existence of the Xia Dynasty, there are many people who are well-known and big V in Zhuxia's own country.

According to the current traditional view of evolution, it is simply impossible to admit that the earth has undergone many civilizations.

The theory of evolution has always maintained that humans today are the only intelligent life on Earth that has ever existed.

According to evolutionary theory, 65 million years ago after the mass extinction.

The era of reptile domination ended, and the earliest primitive mammals evolved rapidly in the long years that followed, gradually replacing reptiles.

More than 50 million years ago, primates, a branch of mammals, came to the fore in evolution.

By 24 million to 35 million years ago, the oldest apes appeared.

These apes are considered to be the direct ancestors of modern humans.

Later, 10 million years ago, among the Australopithecus, Rama australopithecus and Australopithecus achicos were born.

According to evolutionary theory, it wasn't until 2 million years ago that Australopithecus actually evolved into Homo erectus, who could use simple tools.

As for the use of fire, it was not until 1 million years ago.

According to Lu Yuan's speculation, this giant tribe has used fire for at least 2.5 million years.

Obviously, there is a very big difference from the history of modern human development.

If it can finally be proved that Lu Yuan's speculation is correct.

Although it is still impossible to disprove the theory of evolution, it can also make human society more aware of human development.

......

Lu Yuan spent the next few days exploring the nearby desert and Gobi.

After a few days, his harvest was not small, not only found more animal fossils, but also found two human fossils.

But it was the appearance of these two human fossils that made him suspicious.

The two human fossils did not appear alone, and a huge dinosaur fossil was found along with them.

Based on the shape of the fossil, Lu Yuan quickly recognized that the dinosaur fossil he found belonged to the famous triceratops.

One of the humans was riding on the back of a dinosaur when the fossil was found. This made Lu Yuan puzzled.

Triceratops is a genus of herbivorous dinosaurs in the family Ornithischian ceratosaurus in the family Ceratosauridae.

Its fossils are found in the Late Cretaceous Late Maastricht Terraces.

According to research, Triceratops is one of the last dinosaurs to appear.

But they lived between 68 million and 65 million years ago.

Although in recent years some archaeologists believe that the time of the appearance of triceratops has changed somewhat with the traditional view.

Some scholars believe that Triceratops appeared earlier, probably 75 million years ago.

At the same time, they also believe that the triceratops did not go extinct 65 million years ago, but continued to live for nearly 10 million years.

According to these scholars, the extinction of the triceratops is supposed to be 55 million years ago.

Both traditional knowledge and the latest research are far from Lu Yuan's previous speculation of 2.5 million years.

Lu Yuan began to speculate in his heart whether the third-generation giant appeared earlier than he had previously thought.

Lu Yuan shook his head, and he suddenly had a new guess.

He suddenly remembered one thing, the intelligent housekeeper once said that the second generation of humans left the earth 70 million years ago.

The latest research suggests that Triceratops first appeared 75 million years ago.

75 million years ago, this time coincided with the second generation of humans.

"Could it be that the petroglyphs here are left over from the second generation of humans?"

"But according to the intelligent butler, the Giant Clan is the third generation of humans!"

Lu Yuan pressed his temples and turned his head to look at the fossil in front of him.

Then he thought again, "65 million years ago, the earth was clearly in the age of the behemoth.

Since ordinary animals can grow so big, then humans at that time would also grow very big......"

Lu Yuan just thought of this, but found that something was wrong.

He found more fossils than triceratops and giants.

There are also a bunch of fossils of hippos, mammoths, cows, sheep.

These animals are not as old as 70 million years ago.

Lu Yuan felt that his head was getting more and more dizzy for a while......