in Eurasia, and the ancestors of the extant rhino species dispersed from Asia beginning in the Miocene. Fossils of R. unicornis appear in the Middle Pleistocene. In the Pleistocene, the genus Rhinoceros ranged throughout South and Southeast Asia, with specimens located on Sri Lanka. Into the Holocene, some rhinoceros lived as far west as Gujarat and Pakistan until as recently as 3,200 years ago. The Indian and Javan rhinoceroses, the only members of the genus Rhinoceros, first appear in the fossil record in Asia during the Early Pleistocene. The Indian rhinoceros is known from Early Pleistocene localities in Java, South China, India and Pakistan. Molecular estimates suggest the species may have diverged much earlier, around . Although belonging to the type genus, the Indian and Javan rhinoceroses are not believed to be closely related to other rhino species. Different studies have hypothesised that they may be closely related to the extinct Gaindatherium or Punjabitherium. A detailed cladistic analysis of the Rhinocerotidae placed Rhinoceros and the extinct Punjabitherium in a clade with Dicerorhinus, the Sumatran rhinoceros. Other studies have suggested the Sumatran rhinoceros is more closely related to the two African species. The Sumatran rhino may have diverged from the other Asian rhinos as long as 15 million years ago. Characteristics Indian rhinos have a thick grey-brown skin with pinkish skin folds and one horn on their snout. Their upper legs and shoulders are covered in wart-like bumps. They have very little body hair, aside from eyelashes, ear fringes and tail brush. Bulls have huge neck folds. The skull is heavy with a basal length above and an occiput above . The nasal horn is slightly back-curved with a base of about by that rapidly narrows until a smooth, even stem part begins about above base. In captive animals, the horn is frequently worn down to a thick knob. The Indian rhino's single horn is present in both bulls and cows, but not on newborn calves. The horn is pure keratin, like human fingernails, and starts to show after about six years. In most adults, the horn reaches a length of about , but has been recorded up to in length and in weight. Among terrestrial land mammals native to Asia, Indian rhinos are second in size only to the Asian elephant. They are also the second-largest living rhinoceros, behind only the white rhinoceros. Bulls have a head and body length