But not this Nautilus.
Its shell is shaped into a round disk, which is exactly the same as a chrysanthemum fossil, but it is much smaller than an ordinary chrysanthemum fossil. It is a bit like a mini version of a chrysanthemum fossil.
Xiang Yang was somewhat suspicious, "Is this a reversion to our ancestors?"
Xiang Yang didn't believe anything. This was a real chrysanthemum fossil, because it was impossible.
Ammonites became extinct quite early, and it is impossible for any of them to exist alive. Modern humans cannot even see them with their own eyes.
Xiang Yang thought about it carefully. It is said that there is a species of nautilus that looks very similar to the chrysanthemum fossil.
This nautilus itself evolved from ammonite. Although the two creatures developed separately for tens of millions of years after evolution, the appearance of the two creatures is extremely similar. Even if the fossils of the two creatures are placed together, many people cannot tell them apart.
However, this type of nautilus is extremely rare, and many people have only heard of it but have never seen it.
Xiang Yang guessed that this Nautilus should be the legendary Nautilus.
At this time, the little nautilus poked its head out of its shell and carefully looked around. When it saw the huge Xiang Yang standing in front of it, it immediately retracted its head, then lay straight on the ground and pretended to be dead.
Xiang Yang smiled brightly, thinking that most marine creatures had become increasingly powerful after endless years of evolution.
But this Nautilus becomes weaker and weaker as it evolves.
Even today, he no longer has any means of attacking, and when faced with danger he can only lie flat on the ground and pretend to be dead.
Looking back to ancient times, the Nautilus family was also once prosperous.
Let’s not talk about the straight-shelled Nautilus that once dominated the ocean.
Take the ammonite fossil for example. As far as Xiang Yang knows, an ammonite fossil of unconfirmed species with a diameter of more than 2.3 meters was discovered in Colombia.
Once confirmed, that ammonite fossil will be the largest ammonite fossil known to date.
In the eyes of scholars, these ammonite fossils are not only for ornamental purposes. Since the existence of ammonites spans a very long period of time, and their distribution in the sea is also very widespread, the boulders are the most useful fossils for geologists to calculate the age of rocks. Therefore, if scholars only need to analyze ammonites, they can easily infer the age of the rocks.
Of course, the Nautilus remains the most valuable sea snail, more valuable than the ammonite fossil.
Since nautilus fossils are very rare, their prices are very high. Many fossil collectors even use ammonite fossils to impersonate nautilus fossils and sell them.
Of course, this kind of deception cannot fool professionals.
Although Xiang Yang is not a professional, he knows several ways to distinguish between chrysanthemum fossils and nautilus shells.
The simplest identification method Xiang Yang knows is that the most obvious difference between the ammonite and the nautilus is the difference in the seams and patterns on the shell.
Even though the ammonite has complex and multiple folds, the nautilus has simple curves. If it is a fossil that has been dissected in half, you only need to remember that the curves of the ammonite are outward, while those of the nautilus are inward. Just remember these two identification methods and you will basically not be fooled.
Xiang Yang gently flicked the small nautilus that was pretending to be dead in front of him with his fingers. Speaking of which, the nautilus has a connection with humans. This creature has many air chambers in its body. When the nautilus is about to sink in the sea, it will fill the air chambers with water to increase its weight.
However, ascent is the opposite, inflating the air chamber to reduce weight.
Humans used the diving principle of this creature to invent the first nuclear-powered submarine, the Nautilus.
The difference between the modern and prehistoric Nautilus is really huge.
The current body length of the nautilus generally does not exceed 20 centimeters, but in prehistoric times, the shell of the nautilus, like the ammonite, had many different shapes.
Among them, the straight-shell nautilus that Xiang Yang once discovered can grow up to 12.5 meters in length.
That kind of body was a very huge creature even at that time, and the huge shell of the straight-shelled Nautilus was not just for show.
In fact, they are very strong, dozens of times harder than the shells of modern conchs.
If this Nautilus was its ancestor, the straight-shelled Nautilus, and was hit like this by a person, it might turn around and attack Xiang Yang.
But today, the Nautilus had obviously completely lost its ability to attack. When flicked by Xiang Yang's fingers, it simply tightened its shell and continued to pretend to be dead.
Xiang Yang sighed and thought back to the ancient times. In the prehistoric ocean at that time, most creatures could not bite through the shell of the straight-shelled nautilus. For this reason, this creature had briefly dominated the ocean in the Ordovician period. Even the prehistoric trilobites at that time, in order to avoid being eaten to extinction by this giant creature, evolved long and hard stingers to resist the hunting of the straight-shelled nautilus. This shows how powerful the ancestors of the nautilus were.
In contrast, the Nautilus today is not large in size and is not at the top of the food chain. Coupled with the large-scale hunting by humans, it is even facing the risk of extinction. It is really worse than before.
Xiang Yang teased the Nautilus for a while, but the Nautilus kept its head down, and gradually Xiang Yang lost interest in it.
"Forget it, I won't scare you anymore." Xiang Yang stood up and continued to look at other marine life around him.
Having discovered a giant sea cucumber and an almost extinct living nautilus in this sea area in succession, Xiang Yang is now becoming more and more interested in this sea area.
Although Xiang Yang could not catch the nautilus because it was a protected animal, this trip was not without gain for Xiang Yang because he discovered an area of sea that seemed to be rich in rare fish.
After Xiang Yang stood up, the Nautilus carefully poked its head out and then slowly crawled forward.
Seeing that Xiang Yang had no intention of paying attention to it, the Nautilus suddenly became happy. It swayed its body quickly, then swayed in the sea and swam quickly away.
Of course Xiang Yang saw the Nautilus escape, but he couldn't catch it, and if he got close it would scare it, so Xiang Yang ignored the escaped Nautilus.
The seabed was a vast expanse of white. The fish, snails and shells living in this sea were mostly white. So even though Xiang Yang had excellent eyesight, it was still difficult to find any valuable seafood in the vast expanse of white at first glance.
This feeling is like looking for a little white rabbit in the snow. Even if it is lying right in front of you, it is difficult to find it if you don't look carefully.
Of course, Xiang Yang was not in a hurry. His harvest from this trip was already very rich, and he was not in a hurry to catch more valuable seafood. He had plenty of time to search slowly.