Why did trilobites become the "top stream" among ancient creatures?

If rocks are pages of history books recording the changes of the earth, then trilobites are a chapter in this history book.

The long-lasting traces they left in the sea where they once lived have become special texts (fossils) in this book.

Trilobites are the most representative ancient creatures that appeared in the Cambrian period 543 million years ago. They belong to arthropods. The whole body is clearly divided into three parts: head, thorax and tail; the carapace is hard and consists of an axis lobe and two side lobes, hence the name trilobite.

Trilobites reached their peak in the Cambrian and Ordovician periods 500-430 million years ago, and became extinct in the Permian period 240 million years ago. They flourished on Earth for more than 300 million years in the Paleozoic Era and evolved into many species, some as long as 70 cm and some as small as 2 mm.

Although trilobites lived a long time ago, scientists have a fairly complete understanding of their morphology, structure and other characteristics: first, trilobites have a strong shell on their body surface, and they undergo multiple molting cycles during their individual development, so they leave more fossils in the strata than other organisms; second, they reproduce rapidly and are widely distributed; in addition, most trilobite fossils are preserved in fine-textured limestone and shale, so not only can the characteristics of the internal shell be observed clearly, but sometimes the internal structure can also be seen clearly.

Looking at the evolutionary history of trilobites, they have experienced the test of natural selection, avoided the attacks of natural enemies, evolved into many species, and finally solidified in the long river of time. No one knows what kind of hardships and struggles they have experienced. Only through their petrified bodies can we speculate on this historical legend...

Even if the vitality is strong, it cannot resist the changes in ecology and species; even if it is prosperous, it cannot resist the changes in the environment. It is common sense that the fittest survive and the unfit are eliminated. However, as the overlord of today, while enjoying the many resources given by the earth for 4.6 billion years, is it worthwhile to reflect: the myriad resources are given by the earth, and we should cherish them when we enjoy them.