Most endangered mammal in the world!!!
Rhinoceros sondaicus - Javan Rhinoceros, Sunda Rhinoceros, Lesser One-horned Rhinoceros.
Population: Fewer than 50,
Only one known location in the wild, Ujung Kulon NP in Indonesia. 
The Vietnamese Javan Rhino officially declared EXTINCT in 2010

Dicerorhinus sumatrensis - Sumatran Rhinoceros
Population: Fewer than 200. Critically endangered.

Ceratherium simum cottoni - Northern White Rhinoceros, Northern Square-lipped Rhinoceros,
with an Einiosaurus-like horn. 
Population: 7 Individuals

Rhinoceros unicornis - Indian Rhinoceros, Greater One-horned Rhinoceros 
Population: 2,949


 Ceratherium simum simum - Southern White Rhinoceros, Southern Square-lipped Rhinoceros
Population: 20,600

Still in danger from poachers.

Diceros bicornis - Black Rhinoceros
Population: 4,860