▁arg ues ▁that ▁stress ▁f ract ures ▁in ▁the ▁wild ▁do ▁not ▁occur ▁from ▁every day ▁behaviour , ▁such ▁as ▁feed ing - related ▁activities ▁( contra ▁Roth sch ild ▁and ▁Mol nar ). ▁ ▁Head ▁and ▁neck ▁post ure ▁ ▁There ▁is ▁controvers y ▁over ▁how ▁sau rop ods ▁held ▁their ▁heads ▁and ▁ne cks , ▁and ▁the ▁post ures ▁they ▁could ▁achieve ▁in ▁life . ▁Vari ous ▁research ▁looking ▁at ▁the ▁problem ▁from ▁aspects , ▁such ▁as ▁the ▁neutral ▁art ic ulation ▁of ▁the ▁neck ▁verte bra ▁and ▁estim ating ▁the ▁range ▁of ▁motion , ▁the ▁met abol ic ▁and ▁energy ▁requirements ▁of ▁having ▁incred ibly ▁long ▁ne cks , ▁and ▁comparison ▁to ▁living ▁animals , ▁have ▁come ▁to ▁different ▁conclus ions . ▁The ▁claim ▁that ▁the ▁long ▁ne cks ▁of ▁sau rop ods ▁were ▁used ▁for ▁brow sing ▁high ▁trees ▁has ▁been ▁question ed ▁on ▁the ▁basis ▁of ▁calculations ▁of ▁the ▁energy ▁needed ▁to ▁create ▁the ▁ar ter ial ▁blood ▁pressure ▁for ▁the ▁head ▁if ▁it ▁was ▁held ▁u pr ight . ▁These ▁calculations ▁suggest ▁this ▁would ▁have ▁taken ▁up ▁roughly ▁half ▁of ▁its ▁energy ▁int ake . ▁Further , ▁to ▁supply ▁blood ▁to ▁the ▁head ▁vert ically ▁held ▁high ▁would ▁have ▁required ▁blood ▁pressure ▁of ▁around ▁ 7 0 0 ▁mm H g ▁(= ▁ 0 . 9 2 1 ▁bar ) ▁at ▁the ▁heart . ▁This ▁would ▁have ▁needed ▁hearts ▁ 1 5 ▁times ▁the ▁size ▁of ▁the ▁hearts ▁of ▁wh ales ▁of ▁similar ▁size . ▁This ▁has