"illegitimate child" is a common name, not a formal biological term. Its original meaning is "a man who indulges his wife's affair", and it was written as "forgetting eight" at that time. Later, people used "duck" to refer to or compare with "turtle", because the duck head was green in China's past varieties.
Later, it was also called "tortoise". See (Xue Pan in the Red Chamber: Marry a Man as a Turtle and Husband as a Turtle). Now it is basically used as another name for "turtle" all over the country.
The tortoise has a special shell from which the head, tail and limbs can extend and retract. The whole body is box-shaped and can be divided into three parts: head and neck, trunk, limbs and tail. The back of the head is slightly triangular, black or brown-black, the mouth is located in the front of the head, the front of the head is smooth, and the back is fine and scaly. The upper and lower jaws are toothless, and the edge of the jaw is covered with a tough fishy sheath called beak. Nose is located in front of the kiss. Smell and touch are developed. The tortoise is box-shaped, and the whole body is wrapped in a box-shaped turtle shell. Tortoise shell is obviously divided into two parts: the carapace and the abdominal carapace, which are connected by a nail bridge. The carapace and carapace are composed of two layers, the outer layer is the cutin shield from epidermis and the inner layer is the bone plate from dermis. The shield slot between the shields does not overlap with the bone seam of the bone plate, so the turtle shell is extremely strong.
Turtles, also known as turtles, are flat, slightly round or oval. The body surface is covered with soft leather. There is dimethyl on the back and abdomen, and there is a soft horny skirt around the slightly convex dorsal nail, while the abdominal nail is flat, and the side of dimethyl is connected by ligament tissue. The back is usually dark green or yellowish brown with warts arranged vertically. The ventral surface is grayish white or yellowish white. The turtle's neck is long and strong, flexible and flexible. The kiss is pointed and prominent, and there is a pair of nostrils at the front end of the kiss, which is convenient for breathing out of the water. Small eyes, on both sides of the head. The mouth is very wide, located on the ventral surface of the head, with horny hard sheaths on the upper and lower jaws, which can crush hard food. There are short tongues and muscles in the mouth, but they can't stretch freely and can only help swallow food. The limbs of Trionyx sinensis are flat and short, which are located at both sides of the body and can be retracted into the shell. Five fingers on the forelimbs and five toes on the hind limbs. There is a developed webbed membrane between the toes of the limbs, and 1-3 has a hooked claw at the end of the toes, which protrudes out of the webbed membrane. Because the turtle has thick limbs and developed webbed membranes, it can not only crawl on land, but also swim in the water. When it catches food, its powerful forelimbs and claws can also tear up large pieces of food, making it easy to bite and swallow.
The difference between a tortoise and a tortoise
The difference between a turtle and a turtle: The simplest way to distinguish is:
1, the glans penis is round. The tortoise is a kind of tortoise with a pointed head.
The tortoise has a hard shell. Turtles are soft-shelled turtles with smooth surfaces.
There are patterns on the turtle's back, and the turtle's back is black without patterns.
Turtles don't bite. If you touch the tortoise with a branch or something, it will draw its head back. If the tortoise wants to bite, it will bite if it touches the branch with something like a branch.
It's easier for you to understand if you have a picture.