Did hadrosaurs and other iguanodontians run on two legs or four?

[CarnotaurusKing]

The gentleman in this video gets unusually exasperated over the hadrosaurs in Prehistoric Kingdom running on two legs. He also refers to the big "nipple scales" on Triceratops as osteoderms, which I don't think they are?

From a cursory glance, the relatively spindly and shorter forelimbs of hadrosaurs don't seem particularly suited for running at high speeds. Sellers et al (2008) suggests that bipedalism might be more reasonable at higher speeds, but emphasized the need for further study. I could not find any more research on high speed locomotion in ornithopods. If there is further research, or if anyone wishes to put in their own two cents, please feel free.

[andrewsaurus rex]

i thought this had been pretty much settled?  I guess not though.  With long strong back limbs and short thinner front limbs it seems pretty obvious that, assuming they could run, it would have been on two legs.  Four legged stance would probably have been used for ambling along, grazing etc. 

In some ways, hadrosaur's build is reminiscent of the kangaroo, other than the hopping gate and i think roos are not a bad analogy for hadrosaurs.

[Halichoeres]

There's a ton of fossilized trackways showing bipedal locomotion. As an example:
https://journals.plos.org/plosone/article/figure?id=10.1371/journal.pone.0072579.g008