Arsinoitherium belonged to the extinct genus of paenungulate mammals under the extinct order Embrithopoda. The easiest way to recognize an Arsinoitherium was by the horns on its head. A noticeable feature of the Arsinoitherium was the pair of three-foot horns projecting from above the nose and the second pair of tiny, knob-like horns on top of the skull directly behind the more enormous horns. Their larger horns were hollow, and they may have used them to compete with other males and make loud mating calls. 

These huge mammals had similar features with rhinos but had more resemblance with present-day elephants. Arsinoitherium is frequently compared to a rhinoceros in terms of appearance. However, its bone structure was more like that of an elephant as it possessed skulls, feet, and hips. 

Their twin horns, shaped like knives, could grow up to 2.5 feet in length and sometimes even a little over three feet. One interesting fact about these horns is that they never broke, and experts believe they didn’t break because they were covered in keratin. These mammals were about six feet tall and were as long as 11 feet. They also weighed over 5,500 pounds (around 2500 kg).