“Oreodonts”
pencil & oil wash, around 2012

Merycoidodontidaea is correct but less comfortable to spell than oreodonts. The important content is that these belong to the Tylopoda, the most ancient side branch of crown-group artiodactyls that split off the highly diverse bovid lineage even before pigs, whales & hippos, giraffes and deer. Today, only the closely related genera Camelus and Lama remain of the tylopods. They once had a much broader disparity, as the merycoidodontids prove.
On the left, you see the somewhat hippopotamus-like Promerycochoerus, on the right the tapir-like Brachycrus. Both were about 1 m in length and inhabited North America during the Miocene. These studies were later completed in full oil paintings on illustration board, but for some reason I liked the preliminary stages more than the final result. There was no certain project, just an announced topic for Prehistoric Times (those days I had time for stuff).