Rhinoceros the name itself means nose – horned.
What is keratin?
a fibrous protein forming the main structural constituent of hair, feathers, hoofs, claws, horns.
Some rhinoceros are known to have two horns while some have single.
The protein keratin that is found in hair, nails, etc. Is found in the horn or rhinoceros. It has hard bony curve within and is covered with keratin line. Hence it is believed that rhinos have horn made of hair.
Rhino considered to be endangered species for being killed over ages in the myth of medicinal uses of Rhino horn. The studies reveal that the horn is merely made of calcium and other compounds and comprises of keratin but no evidence has been found on it during major diseases.
Now that the law has claimed killing of Rhino and trading for horn as illegal, these species are taken care of in wildlife sanctuary.