It has had a confusing history, being considered both a hadrosaurid and a ceratopsid, or both at the same time (chimeric).
[1] This is not much material for naming a new genus, and it was largely ignored until the mid-1990s, when the hypothesis that it was really a ceratopsid appeared.
[2] Shortly thereafter, a new revision appeared that showed that the characteristics listed as unusual for Arstanosaurus were really based on perspective, and that the maxilla was from an animal like Bactrosaurus, albeit indeterminate (a dubious name).
[5] A hadrosauroid from the Bayan Shireh Formation (informally called "Gadolosaurus") has at times been identified as Arstanosaurus, but is clearly a distinct genus.
[6][7][8] As a hadrosaurid, Arstanosaurus would have been a bipedal/quadrupedal herbivore, eating plants with sets of ever-replacing teeth stacked on each other.