The enormous size, unique horn and prehistoric appearance of the Greater One-horned Rhinoceros [Rhinoceros unicornis] sets it apart as one of the most conspicuous mammals of South Asia, because of its highly valued horn, it is also one of the most endangered. It is the largest of the three extant species of rhinoceroses found in Asia, the other two being the Javan Rhinoceros [Rhinoceros sondaicus] and the Sumatran Rhinoceros [Dicerorhinus sumatrensis], both of which have been