Sea turtles are a collective term for marine turtles in the order Turtles, family Turtles, and family Turtles. Body length 0.75-2 meters, weight 45-1000 kilograms. Distributed in the South Pacific and Indian Ocean. In China, it is distributed from Shandong coast in the north to Guangdong coastal provinces, Taiwan, Hainan and other provinces in the south, especially the South China Sea Islands. Most of them live in shallow coastal waters, bays, coral reefs, and estuaries that flow into the sea. Feed on macroalgae, cephalopods, crustaceans, and fish and shrimp. They are one of the oldest animals in the world, appearing on Earth more than 200 million years ago, so archaeologists consider them as "living fossils".