Megacerops

Megacerops ("large-horned face") is an extinct genus of brontothere, an extinct group of rhinoceros-like browsers traditionally classified as relatives of horses. Megacerops was endemic to North America during the Late Eocene, during the Chadronian land mammal age.

Chadronian brontotheres are well represented in the fossil record, known from several skeletons and hundreds of complete skulls. Because the fossils vary considerably in the size and shape of the horns, close to fifty species of Chadronian brontotheres have been named historically. Poor stratigraphic data for the majority of the fossils has further complicated the taxonomy. Today, variations among the fossils are considered to be the result of sexual dimorphism and other individual variation. Only one Chadronian brontothere species is confidently considered to be valid, M. coloradensis. Rare fossils with bifurcating horns may represent a second species, M. kuwagatarhinus. Several historical generic names now considered synonyms of Megacerops remain common in popular culture, such as Brontotherium, Brontops and Titanotherium.

Although similar to modern rhinoceros, Megacerops was closer to elephants in size. The largest known Megacerops may have been over 2.5 meters (8 ft 2 in) tall at the shoulder and could have weighed up to five tonnes. They were the largest animals in their environment and likely too large to be preyed upon by any contemporary predator. The horns of Megacerops, its signature feature, were anatomically similar to the ossicones of modern giraffes and are believed to have been used in intraspecific combat. Paleoclimatological models of the Eocene, and isotope analyses of Megacerops teeth, suggest that they lived in warm temperate to subtropical forests and woodlands, and preferred moist environments.