Saving the Rhino
Paleontologists believe that at least 30 genera and 60 different species of rhino ancestors once inhabited North America, Europe, Asia and Africa. The extinct species Paraceratherium, commonly referred to as the “giraffe-rhinoceros”, was the largest land mammal that ever lived. Its head reached a height of nearly 28 feet – as tall as a three-story building – and paleontologists estimate that it may have weighed as much as 20 tons! The smallest rhino ancestors were the Hyracodontidae, which were only the size of dogs. There was also a group of aquatic, hippopotamus-like rhinos, the Amynodontidae, that lived in North America and Asia.
The closest living rhino relatives are tapirs, horses and zebras. These animals are known as perissodactyls or odd-toed ungulates. Even toed-ungulates are called artiodactyls and include cattle, deer, antelopes, goats, sheep, pigs, camels and llamas. Rhinos have three toes on each foot so, in a way, their tracks resemble the Ace of Clubs.
All five rhino species are threatened with extinction. Populations of two species – greater one-horned and white – were reduced to fewer than 100 animals in the early 20th Century, but because of concerted efforts by governments and dedicated conservationists, have rebounded into the thousands or tens of thousands since that time. Africa’s black rhino numbered around 65,000 in 1973, and were reduced to only a few thousand animals by the early 1990s, but strategic interventions have helped to double its population since then. We have no reliable historical population estimates for the Sumatran and Javan rhinos, but each is now believed to number one hundred individuals or less, and both are threatened with imminent extinction. Despite the current poaching crisis, overall rhino numbers continue to slowly increase.