▁of ▁the ▁animal , ▁Wed el ▁( 2 0 0 3 ) ▁states ▁they ▁are ▁also ▁likely ▁connected ▁to ▁air ▁sac s , ▁as ▁in ▁birds . ▁ ▁James ▁Sp ot ila ▁et ▁al . ▁( 1 9 9 1 ) ▁con cludes ▁that ▁the ▁large ▁body ▁size ▁of ▁sau rop ods ▁would ▁have ▁made ▁them ▁unable ▁to ▁maintain ▁high ▁met abol ic ▁rates ▁because ▁they ▁would ▁not ▁have ▁been ▁able ▁to ▁release ▁enough ▁heat . ▁They ▁assumed ▁sau rop ods ▁had ▁a ▁re pt ilian ▁resp ir atory ▁system . ▁Wed el ▁says ▁that ▁an ▁av ian ▁system ▁would ▁have ▁allowed ▁it ▁to ▁dump ▁more ▁heat . ▁Some ▁scient ists ▁state ▁that ▁the ▁heart ▁would ▁have ▁had ▁trouble ▁sust aining ▁sufficient ▁blood ▁pressure ▁to ▁o xygen ate ▁the ▁brain . ▁O thers ▁suggest ▁that ▁the ▁near - horizontal ▁post ure ▁of ▁the ▁head ▁and ▁neck ▁would ▁have ▁elimin ated ▁the ▁problem ▁of ▁supp lying ▁blood ▁to ▁the ▁brain ▁because ▁it ▁would ▁not ▁have ▁been ▁elev ated . ▁ ▁James ▁Far low ▁( 1 9 8 7 ) ▁calcul ates ▁that ▁an ▁A pat osa urus - s ized ▁din osa ur ▁about ▁ ▁would ▁have ▁possessed ▁ ▁of ▁fer ment ation ▁contents . ▁Assuming ▁A pat osa urus ▁had ▁an ▁av ian ▁resp ir atory ▁system ▁and ▁a ▁re pt ilian ▁rest ing - met abol ism , ▁Frank ▁Pal ad ino ▁et al . ▁( 1 9 9 7 ) ▁estimate ▁the ▁animal ▁would ▁have ▁needed ▁to ▁consume ▁only ▁about ▁