One of the most interesting facts about rhinoceroses is that they are descendants of some of the largest land animals to live on the planet. Prehistoric rhinos, called Indricotherium, stood over 17 feet tall at the shoulder and weighed as much as 66,000 pounds. These large rhinos were covered in thick fur and fed on the grasses and vegetation of their open habitats.
Female rhinos produce a single offspring every other year after a lengthy gestation that can exceed 500 days in length. Their young are active soon after they are born, and they stay with their mother until she gives birth to another offspring. The mothers vigorously defend their young against predators.
There are five living species of rhinoceros. Two species live in Africa, and three species live in Asia. According to the University of Michigan's Department of Zoology, African rhinos are more aggressive than the Asian species are. This manifests in the way the animals fight. African animals rely on their horns, while Asian species prefer to use their bottom teeth.
Rhinoceroses can live for 50 years or longer. Males become sexually mature between 7 and 10 years of age, while females become mature earlier, occasionally when they are 6 years of age.