1. baiji (scientific name: Lipotes vexillifer), also known as baiji and baiji, is a kind of freshwater cetacean baiji, which is only found in the middle and lower reaches of the Yangtze River in China. It has a long snout, a spindle-shaped body, bare and hairless skin, likes to live in groups, is gentle and cautious, has seriously degraded audio-visual organs and has a particularly sensitive sonar system. Baiji dolphin is a warm-blooded animal that breathes with its lungs and is known as the "giant panda in the water". In the 20th century, due to various reasons, its population decreased and was estimated to be less than 50 in 2002. Baiji dolphin is not only listed as a national first-class wild protected animal, but also one of the most endangered animals in the world. On August 8, 2007, a report was published in the journal of Biological Letterhead of the Royal Society, officially announcing the functional extinction of the baiji.

2. Sumatran tiger. Sumatrae) is the smallest tiger of its kind, with a male weight of 65,438+000-65,438+050 kg and a female weight of 75-65,438+000 kg. It has long cheek hair, a long beard and a yellow body. The fur of Sumatra tiger is the darkest of all tigers, with obvious black stripes, small spacing between stripes, stripes often arranged in pairs, and stripes on the front legs. Only distributed in Sumatra, Indonesia. Habitat environments range from plain forests to mountains. There are about 400-500 wild Sumatran tigers, mainly distributed in five national parks in Indonesia.