Aclistomycter is an extinct genus of oreodont. It lived during the early Chadronian subepoch 37.2—33.9 mya, existing for approximately 3 million years. from the Chambers Tuff Formation near Adobe Springs in Presidio County, Texas. Aclistomycter was a very small herbivorous artiodactyl with a short face, small, but tusk-like canine teeth.