The subspecies inermis is almost certainly extinct, and annamiticus is restricted to a few scattered groups in southern Laos, southern Viet Nam, and Cambodia. There long was doubt whether rhinos even survived in Indochina, and if so, whether they represented R. sondaicus or Dicerorhinus sumatrensis. Subsequently, Schaller et al. A black nasal horn, reaching a maximum length of 529 mm, is present in both sexes. The hide is generally gray brown, becomes pinkish in the skin folds, and is covered with rivetlike knobs.
Males show enormous development of the neck folds.
The greater Indian rhinoceros originally occurred mainly in alluvial plain grasslands, where the grass grew up to 8 meters tall. It also was found in adjacent swamps and forests. Its range now has been so restricted by human activity that it often must use cultivated areas, pastures, and modified woodlands. Activity takes place mostly at night, in the early morning, and in the late afternoon. The middle of the day commonly is spent resting in the shade or in mud wallows.