Brontops robustus skeleton. Brontops (thunder face) is an extinct genus of rhinoceros-like perissodactyl mammal. A typical brontothere, Brontops was a huge rhinoceros-like creature standing over 8 feet tall at the shoulder. It looked similar to the better known Brontotherium, possessing the same pair of blunt, horn-like protrusions on its snout, though they were considerably shorter. though the species B. dispar, could be about the size of a modern-day white rhino. This animal appeared during Cenozoic era, the most recent era of geologic time, from about 65 million years ago to the present. The Cenozoic Era is characterized by the formation of modern continents and the diversification of mammals and plants. Grasses also evolved during the Cenozoic. The climate was warm and tropical toward the beginning of the era and cooled significantly in the second half, leading to several ice ages. Humans first appeared near the end of this era.