Sirenian tusked mammal found from eastern africa to australia ; the flat tail .

见于非洲东部到澳大利亚的有尖牙的海牛目哺乳动物；扁平的尾巴分两叉。

Sirenian mammal of tropical coastal waters of america ; the flat tail is rounded .

产于美洲热带沿海水域的海牛类哺乳动物。