Other basal ornithopods have sometimes been linked to Othnielosaurus, particularly Hexinlusaurus, considered by at least one author to be a species of "Othnielia", O. multidens.
Drugi primitivni ornitopodi su ponekada povezani sa Othnielosaurusom, osobito Hexinlusaurus, kojeg barem jedan autor smatra vrstom roda "Othnielia", O. multidens.