 Dollo 's specimens allowed him to show that Owen 's prehistoric pachyderms were not correct for Iguanodon . He instead modelled the skeletal mounts after the cassowary and wallaby , and put the spike that had been on the nose firmly on the thumb . He was not completely correct , but he also had the disadvantage of being faced with some of the first complete dinosaur remains . A problem that was later recognised was the bend he introduced into the tail . This organ was more or less straight , as shown by the skeletons he was excavating , and the presence of ossified tendons . In fact , to get the bend in the tail for a more wallaby or kangaroo @-@ like posture , the tail would have had to be broken . With its correct , straight tail and back , the animal would have walked with its body held horizontal to the ground , arms in place to support the body if needed . 
 Dollo <a href='null_genetive' title='1'><mark>'s</mark></a>specimens allowed him to show that Owen <a href='null_genetive' title='2'><mark>'s</mark></a>prehistoric pachyderms <a href='negative_concord' title='3'><mark>were</mark></a> <a href='negative_concord' title='4'><mark>not</mark></a>correct for Iguanodon . He instead <a href='uninflect' title='5'><mark>modelled</mark></a> the skeletal mounts after the cassowary and wallaby , and put the spike <a href='null_relcl' title='6'><mark>that</mark></a>had been on the nose firmly on the thumb . He <a href='negative_concord' title='7'><mark>was</mark></a> <a href='negative_concord' title='8'><mark>not</mark></a>completely correct , but he also had the disadvantage of being faced with some of the first complete dinosaur <a href='uninflect' title='9'><mark>remains</mark></a> . A problem <a href='null_relcl' title='10'><mark>that</mark></a>was later recognised was the bend he introduced into the tail . This organ was more or less straight , as shown by the skeletons he was excavating , and the presence of ossified tendons . In fact , to get the bend in the tail for a more wallaby or kangaroo @-@ like posture , the tail would <a href='been_done' title='11'><mark>have</mark></a> had to be broken . With its correct , straight tail and back , the animal would <a href='been_done' title='12'><mark>have</mark></a> walked with its body held horizontal to the ground , arms in place to support the body if needed . 
Dollo  specimens allowed em to show that Owen  prehistoric pachyderms ain't correct for Iguanodon . He instead modeled da skeletal mounts after the cassowary and wallaby , and put the spike had been on the nose firmly on the thumb . He ain't completely correct , but he also had the disadvantage of bein faced with sum of the first complete dinosaur remain . A problem was later recognised was tdabend he introduced into thdaail . dis organ was more or less str8 , as shown by thedaeletons he was excavating , and the dasence of ossified tendons . In fact , to get the bend in the tda for a more wallaby or kangaroo @-@ like posture , the tail would done had to be broken . wit its correct , straight tail and bk , the andal would done walked with its body held horizontal to the groda , arms in place to support the bodyda needed .