 The arms of I. bernissartensis were long ( up to 75 % the length of the legs ) and robust , with rather inflexible hands built so that the three central fingers could bear weight . The thumbs were conical spikes that stuck out away from the three main digits . In early restorations , the spike was placed on the animal 's nose . Later fossils revealed the true nature of the thumb spikes , although their exact function is still debated . They could have been used for defense , or for foraging for food . The little finger was elongated and dextrous , and could have been used to manipulate objects . The phalangeal formula is 2 @-@ 3 @-@ 3 @-@ 2 @-@ 4 , meaning that the innermost finger ( phalange ) has two bones , the next has three , etc . The legs were powerful , but not built for running , and each foot had three toes . The backbone and tail were supported and stiffened by ossified tendons , which were tendons that turned to bone during life ( these rod @-@ like bones are usually omitted from skeletal mounts and drawings ) . 
 The arms of I. bernissartensis <a href='uninflect' title='1'><mark>were</mark></a> long ( up to 75 % the length of the legs ) and robust , with rather inflexible hands built so that the three central fingers could bear weight . The thumbs <a href='uninflect' title='2'><mark>were</mark></a> conical spikes <a href='null_relcl' title='3'><mark>that</mark></a>stuck out away from the three main digits . In early restorations , the spike was placed on the animal <a href='null_genetive' title='4'><mark>'s</mark></a>nose . Later fossils revealed the true nature of the thumb spikes , although their exact function is still debated . They could <a href='been_done' title='5'><mark>have</mark></a> been used for defense , or for foraging for food . The little finger was elongated and dextrous , and could <a href='been_done' title='6'><mark>have</mark></a> been used to manipulate objects . The phalangeal formula <a href='drop_aux' title='7'><mark>is</mark></a>2 @-@ 3 @-@ 3 @-@ 2 @-@ 4 , meaning that the innermost finger ( phalange ) <a href='got' title='8'><mark>has</mark></a> two bones , the next <a href='got' title='9'><mark>has</mark></a> three , etc . The legs <a href='uninflect' title='10'><mark>were</mark></a> powerful , but not built for running , and each foot had three toes . The backbone and tail <a href='uninflect' title='11'><mark>were</mark></a> supported and stiffened by ossified tendons , which <a href='uninflect' title='12'><mark>were</mark></a> tendons <a href='null_relcl' title='13'><mark>that</mark></a>turned to bone during life ( these rod @-@ like bones are usually omitted from skeletal mounts and drawings ) . 
The arms of I. bernissartensis was long ( up to 75 % da length of the legs ) and robust , with rather inflexible hands built so that the three central fingers could bear weight . Tdathumbs was conical spikes stuck outt away from the three main digits . In early restorations , thdapike was placed on thedaimal  nose . Later fossils revealed the dae nature of the thumb spikes , although their exact function is still debated . They could done been used for defense , or fa foraging for food . The ldafinger was elongated and dextrous , and could done been used to manipulate objects . The phalangeal formula 2 @-@ 3 @-@ 3 @-@ 2 @-@ 4 , meaning dat the innermost finger ( phalange ) got two bones , the nxdaot three , etc . The legs was powerful , but not built for running , and each foot had three toes . The bacdane and tail was supported and stiffened by ossified tendons , which was tendons turned to bone during life ( dem rod @-@ like bones r usually omitted from skeletal mounts and drawings ) .