Embolotherium was one of the first truly giant mammals of Cenozoic. Up to 2.5 meters tall, it had a brain no bigger than an orange, and was not the brightest of beasts. It weighed around 2 tons and had a 70 cm. bony growth on its nose, the reason for its name, 'battering-ram beast'. Embolotherium was sexually dimorphic, with the females' bony growth being way smaller than the males.
Embolotherium was a herbivore and it lived during the late Eocene time period, 40-35 MYA in Mongolia, the Gobi Desert. It was a herbivore that fed only on the leaves of shrubs and bushes, for grass hadn't evolved yet. It had few predators, but as it was shown in WWB, the giant hunter-scavenger Andrewsarchus would harass them from time to time, and even possibly even kill a weakened animal.
Not unlike the case of the Iguanodonts and other plant-eating dinosaurs earlier in time, Embolotherium and the other brontotheres were one of the most successful groups of mammals around the late Eocene, they were found across the northern hemisphere in herds of hundreds. In another difference to rhinos, the outgrowths more for show than for the actual head–butting: the bone crests were far too brittle for that.
Females embolotheres were fiercely protective of their young. Even when their calves died, it would be impossible to say whether the mothers understood if their calves were dead. Like most animals, female embolotheres had a very strong bond with their offspring, and would defend them for as long as they could.
By 28 MYA Embolotherium and other brontotheres died out because of the climate change that killed several of their food plants and the appearance of better, more efficient and modern herbivores, such as Indricotheres and Chalicotheres that outcompeted the older, less advanced brontotheres and eventually drove them into extinction.