Orangemeryx hendeyi is the most common large mammal at the basal Middle Miocene site of Arrisdrift, Namibia. In the new collections from the locality there are several specimens, including frontals with appendages and the brain case, which were not well represented in the previously described samples. These discoveries throw a great deal of light on the mode of insertion and orientation of the frontal appendages, as well as on the morphology of the brain case and basicranium, all of which permits a better phylogenetic interpretation of the genus, and in a wider sense, of the family Climacoceratidae. There is meagre postcranial evidence for the existence of another species of large ruminant at Arrisdrift, and a couple of smaller specimens about the size of Walangania, but no dentitions corresponding to these forms are known from the site.