▁history ▁of ▁their ▁study , ▁scient ists , ▁such ▁as ▁Os born , ▁have ▁spec ulated ▁that ▁sau rop ods ▁could ▁rear ▁up ▁on ▁their ▁h ind ▁legs , ▁using ▁the ▁tail ▁as ▁the ▁third ▁' leg ' ▁of ▁a ▁tri pod . ▁A ▁ske let al ▁mount ▁dep ict ing ▁the ▁di pl od oc id ▁Bar osa urus ▁l ent us ▁re aring ▁up ▁on ▁its ▁h ind ▁legs ▁at ▁the ▁American ▁Museum ▁of ▁Natural ▁History ▁is ▁one ▁illustr ation ▁of ▁this ▁hypothesis . ▁In ▁a ▁ 2 0 0 5 ▁paper , ▁Roth sch ild ▁and ▁Mol nar ▁reason ed ▁that ▁if ▁sau rop ods ▁had ▁adopted ▁a ▁b ip ed al ▁post ure ▁at ▁times , ▁there ▁would ▁be ▁evidence ▁of ▁stress ▁f ract ures ▁in ▁the ▁for el imb ▁' hand s '. ▁However , ▁none ▁were ▁found ▁after ▁they ▁exam ined ▁a ▁large ▁number ▁of ▁sau rop od ▁ske let ons . ▁[[ File : Bar osa urus ▁mount ▁ 1 . jpg | th umb | left | u pr ight | Mount ed ▁ske leton ▁of ▁Bar osa urus ▁l ent us , ▁dep icted ▁in ▁a ▁re aring ▁tri pod al ▁st ance ]] ▁Heinrich ▁Mall ison ▁( in ▁ 2 0 0 9 ) ▁was ▁the ▁first ▁to ▁study ▁the ▁physical ▁potential ▁for ▁various ▁sau rop ods ▁to ▁rear ▁into ▁a ▁tri pod al ▁st ance . ▁Mall ison ▁found ▁that ▁some ▁characters ▁previously ▁linked ▁to ▁re aring ▁adapt ations ▁were ▁actually ▁un