Why is a turtle engraved on the ancient seal?

In ancient times, turtles were noble. The gold seals and buttons used by prime ministers, princes and generals in the Han dynasty were turtle-shaped; The silver seal and silver buckle used by officials with a salary of more than 2000 stones are also turtle-shaped. Small official seals are not allowed to be turtle-shaped. The Tang dynasty also stipulated that the stone tablet in front of the tomb of a senior official with five or more products can be a turtle, that is, a turtle back stone tablet; For officials under five grades, the base of the stone tablet in front of the tomb cannot be carved into a turtle shape, but can only be carved into other shapes. Also, officials in the Tang Dynasty used to wear fish bags, but Wu Zetian gave them for two years and changed them into turtle bags. At that time, turtles were regarded as noble and sacred things. The reason is:

First, because turtles live a long life and can starve, it doesn't matter if they don't drink or eat for a long time. Its vitality is extremely strong, and its life span can reach over 100 years.

Second, in ancient times, turtle shells were used as money and turtles were a symbol of wealth. According to the records in Hanshu, there are four kinds of turtles: yuan gui, male turtle, queen turtle and son turtle. Turtles are treasures, and people regard them as treasures;

Third, tortoise shell is a tool for divination and writing, and it is an indispensable necessity in people's lives. For these reasons, ancient people regarded turtles as treasures.