 Furthermore , it appears that Iguanodon became more quadrupedal as it got older and heavier ; juvenile I. bernissartensis have shorter arms than adults ( 60 % of hindlimb length versus 70 % for adults ) . When walking as a quadruped , the animal 's hands would have been held so that the palms faced each other , as shown by iguanodontian trackways and the anatomy of this genus 's arms and hands . The three toed pes ( foot ) of Iguanodon was relatively long , and when walking , both the hand and the foot would have been used in a digitigrade fashion ( walking on the fingers and toes ) . The maximum speed of Iguanodon has been estimated at 24 km / h ( 15 mph ) , which would have been as a biped ; it would not have been able to gallop as a quadruped . 
 Furthermore , it <a href='uninflect' title='1'><mark>appears</mark></a> that Iguanodon became more quadrupedal as it got older and heavier ; juvenile I. bernissartensis <a href='got' title='2'><mark>have</mark></a> shorter arms than adults ( 60 % of hindlimb length versus 70 % for adults ) . When walking as a quadruped , the animal <a href='null_genetive' title='3'><mark>'s</mark></a>hands would <a href='been_done' title='4'><mark>have</mark></a> been held so that the palms faced each other , as shown by iguanodontian trackways and the anatomy of this genus <a href='null_genetive' title='5'><mark>'s</mark></a>arms and hands . The three toed pes ( foot ) of Iguanodon was relatively long , and when walking , both the hand and the foot would <a href='been_done' title='6'><mark>have</mark></a> been used in a digitigrade fashion ( walking on the fingers and toes ) . The maximum speed of Iguanodon <a href='been_done' title='7'><mark>has</mark></a> been estimated at 24 km / h ( 15 mph ) , which would have been as a biped ; it would <a href='negative_concord' title='8'><mark>not</mark></a>have <a href='negative_concord' title='9'><mark>been</mark></a> able to gallop as a quadruped . 
Furthermore , it appear that Iguanodon became more quadrupedal as it got older and heavier ; juvenile I. bernissartensis got shorter arms den adults ( 60 % of hindlimb length versus 70 % fir adults ) . When walking as a quadruped , the animal  hands would done been held so dat the palms faced each other , as shown by iguanodontian trackways and da anatomy of this genus  arms and hands . The three toed pes ( foot ) of Iguanodon was relatively long , and when walking , both tdahand and the foot would done been used in a digitigrade fashion ( walkin on thdaingers and toes ) . Thedaximum speed of Iguanodon done been estimated at 24 km / h ( 15 mph ) , which would have been as a biped ; it would have ain't able to gallop as a quadruped .