Merycoidodontoidea, commonly known as oreodonts, are an extinct group of hoofed mammals that lived in North America. They were herbivores that fed on grasses, leaves, and shrubs, using their flat teeth to grind tough vegetation.nMost species were about the size of a sheep or small pig. They lived in woodlands, open forests, and grasslands. Fossil evidence suggests they may have lived in groups.nSpecifications:nnSkull Length 16.7 cm (6.6 in)nSkull Width 10.6 cm (4.2 in)nSkull Height 6.7 cm (2.6 in)