Blastomeryx is an extinct genus of musk deer endemic to North America. It lived during the Miocene epoch 20.4—10.3 mya, existing for approximately .[1] There may be only one species, Blastomeryx gemmifer.[2]
Blastomeryx was long and looked like a modern chevrotain. Its canines were elongated into tusks which it probably used to uproot plants and fend off predators. While Blastomeryx (as well as modern musk deer) lacked antlers, a Middle Miocene species had bony knobs on its skull, which have been interpreted as incipient horns.[3]