Rhino species are believed to have existed on earth since the tertiary era (65 million years ago), a time of extinct dinosaurs. At that time, there were estimated to be 30 species of rhino in the world.
Currently there are only five species of rhino left, with two of them found in Indonesia, the Sumatran rhino and the Javan rhino, which are both endangered.
Rhino is one of the oldest animals in the world. The World Wildlife Fund (WWF) organization, commemorates international rhino day on September 22 every year.
Rhinos can be found in Africa and Asia. The first rhino that ever lived was named the wolly rhino that had lived on earth about 50 million years ago.