related ▁( such ▁as ▁the ▁wide - set ▁hip ▁b ones ▁of ▁tit an osa urs ) ▁or ▁would ▁have ▁h inder ed ▁re aring . ▁For ▁example , ▁tit an osa urs ▁had ▁an ▁unus ually ▁flexible ▁back bone , ▁which ▁would ▁have ▁decre ased ▁stability ▁in ▁a ▁tri pod al ▁post ure ▁and ▁would ▁have ▁put ▁more ▁stra in ▁on ▁the ▁mus cles . ▁Like wise , ▁it ▁is ▁unlikely ▁that ▁bra ch ios aur ids ▁could ▁rear ▁up ▁onto ▁the ▁h ind ▁legs , ▁as ▁their ▁center ▁of ▁gravity ▁was ▁much ▁farther ▁forward ▁than ▁other ▁sau rop ods , ▁which ▁would ▁cause ▁such ▁a ▁st ance ▁to ▁be ▁un stable . ▁ ▁Di pl od oc ids , ▁on ▁the ▁other ▁hand , ▁appear ▁to ▁have ▁been ▁well ▁adapted ▁for ▁re aring ▁up ▁into ▁a ▁tri pod al ▁st ance . ▁Di pl od oc ids ▁had ▁a ▁center ▁of ▁mass ▁directly ▁over ▁the ▁h ips , ▁giving ▁them ▁greater ▁balance ▁on ▁two ▁legs . ▁Di pl od oc ids ▁also ▁had ▁the ▁most ▁mobile ▁ne cks ▁of ▁sau rop ods , ▁a ▁well - mus c led ▁pel vic ▁g ird le , ▁and ▁tail ▁verte bra e ▁with ▁a ▁special ised ▁shape ▁that ▁would ▁allow ▁the ▁tail ▁to ▁bear ▁weight ▁at ▁the ▁point ▁it ▁touched ▁the ▁ground . ▁Mall ison ▁concluded ▁that ▁di pl od oc ids ▁were ▁better ▁adapted ▁to ▁re aring ▁than ▁ele ph ants , ▁which ▁do ▁so ▁occasionally ▁in ▁the ▁wild . ▁He ▁also