They possessed prominent canines and molars with bunodont cusps, bulging dental wreaths, and wrinkled enamel.

Their upper molars were usually squared, due to the enlargement and displacement of the metaconule, but there was also a small hypocone and hypoconule.

Their lower molars increased in size as they proceeded to the bottom of the jaw, and the paraconid was small or absent.

[3] The family Helohyidae was established by Marshall in 1877 to accommodate some forms of early artiodactyl mammals of the American Eocene.

The artiodactyl Simojovelhyus was once thought to be an unusually late-surviving genus of helohyid from the Upper Oligocene (extending the families temporal range by around 10 million years),[5] however recent studies consider it a peccary.