Turtles refer broadly to turtles and turtles in a broad sense, and species under the tortoise family in a narrow sense.
<h3>Basic characteristics</h3>
Turtles are also known as turtles, and turtles are reptiles that evolved centered on carapace. Turtles were first seen in the early Triassic period, when fully developed carapaces were developed. Early turtles may not have been able to retract their heads and limbs into their shells as they do today. Turtles have been on Earth for tens of millions of years, and dinosaurs are contemporaneous animals. Simply put, there are three types of turtles: water turtles, tortoises, and semi-aquatic turtles. The real turtle refers to the grass turtle, and the male adult of this turtle will turn black, so it is called a turtle. It belongs to the reptiles, turtles and turtles, turtles, turtles, and turtle subfamily in animal taxonomy, and is one of the most common turtles and tortoises. Turtles are distributed almost everywhere in China, but the production of the provinces in the middle and lower reaches of the Yangtze River is higher. It is also produced in all parts of Guangxi, especially in southeastErn Guizhou, Guinan and other places. It is mainly distributed in Japan, Brazil and North Korea.
Mother Chinese grass turtle
The dorsal carapace is 10 to 18 cm long and 6 to 12 cm wide. The dorsal carapace of males is nearly black, and the females are tanned.
It is divided into head, neck, body, tail and limbs. A special morphological structure that is significantly different from other reptiles is the turtle shell, which contains a wide and short body. The shell consists of arched dorsal carapace and flattened ventral carapace: the ventral carapace extends on the side of the body and is connected to the dorsal carapace by bone slits or ligaments, and this elongated part is called the nail bridge. The head , limbs , and tail protrude from the edges of the shell and generally retract into the shell ( with the exception of flat-breasted turtles ) . Both the dorsal and ventral carapaces consist of two layers: the inner layer is composed of several bone plates, and the outer layer is composed of several shields. The leatherback turtle family is completely devoid of shields, indicating that the skin is covered with leathery skin, and its bone plates have also degenerated into many small bone pieces.
The upper and lower jaws of turtles are toothless, and the jaw margin is sheathed with sheaths, called beaks. The turtle has a muscular tongue and cannot stick out. There are eyelids and transient membranes, and the pupils are rounded. The sense of hearing is not acute, the sense of touch and smell is more developed, and the lungs breathe. The diarrhea foramen is round or longitudinally fissured. The handover is single.
<h3>Main features</h3>
The turtle has thick limbs and a hard shell, and the head, tail and limbs can be indented into the shell. The shell of the turtle can be boiled into turtle gel, which is commonly used in Traditional Chinese medicine. Sometimes the leatherback turtle family and turtle family are classified as large or medium-sized sea turtles, whose limbs become paddle-shaped when swimming, and are native to tropical and subtropical oceans. Their meat contains fat, which can be made into oil; eggs can be eaten; and A can also be used as a traditional Chinese medicine. Some species of turtles have a long lifespan, some up to 300 years. Common large tortoise species are tortoises, which are 1.5 m long and weigh 200 kg, and are famous for their ability to carry people to crawl. The green turtle is a favorite exhibit animal, it is actually a golden turtle or water turtle that grows green algae on the back of the carapace.
This article was edited by headline encyclopedia users Mario Luigi X, dppkne001, Aichi Inui, and Xiao Chu Hao Ya.