Rhinos are related, somewhat distantly, to a favourite domesticated animal and pet: the horse!
Horses or equids, tapirs and rhinos are in the same group or ‘order’ and are known as ‘Perissodactyls’. This means they have some things in common and they have come from the same type of animal, a common ancestor, millions of years ago. They are ungulates which all browse (eat trees and bushes) or graze (eat grass), and they all have an odd number of toes or hooves on their feet. The middle toe is usually larger, in horses or equids, the middle toe has become so large that the others have shrunk away over time.
It is thought that both horses and tapirs originated and evolved in North America. Rhinos may have developed in Asia from tapir-like animals before spreading out. It is even thought that once there was an Asian rhinoceros that was so big it weighed twice as much as an elephant!
When the world’s species are organised into the classification system we can see where rhinos fit. They are of course members of the animal kingdom, they have a backbone (chordata) and they are mammals. We know this because mammals are warm blooded, grow hair and have live young which they suckle with milk. They fit into the order which represents the ungulates with an odd number of toes, the perissodactyls. There is then a sub-order, where we can see that rhinos are in fact more closely related to Tapirs. Then there are the families (equids, rhinos and tapirs), and within those families are the species which we are familiar with.
The rhino species alive today are the black and white rhinos from Africa and the greater one-horned, Sumatran and Javan rhinos from Asia. Some examples of tapir species include the Brazilian tapir from South America and the Malayan tapir from Asia. Finally some examples of equid species include the domestic horse, the wild horse (Przewalski’s horse) and zebras.
So next time you see a horse, or if you’re lucky enough to ride one or own one as a pet, think about those distant relatives of theirs. Horses can be pretty strong, and those huffing and snorting noises they can make, rhinos do that too!
