▁and ▁Bar ap as aur us , ▁had ▁such ▁for efe et ). ▁The ▁front ▁feet ▁were ▁so ▁modified ▁in ▁e us au rop ods ▁that ▁individual ▁digits ▁would ▁not ▁have ▁been ▁visible ▁in ▁life . ▁ ▁The ▁arrangement ▁of ▁the ▁fore foot ▁b one ▁( met ac arp al ) ▁columns ▁in ▁e us au rop ods ▁was ▁semi - circ ular , ▁so ▁sau rop od ▁fore foot ▁prints ▁are ▁horses ho e - sh aped . ▁Un like ▁ele ph ants , ▁print ▁evidence ▁shows ▁that ▁sau rop ods ▁lack ed ▁any ▁f les hy ▁padding ▁to ▁back ▁the ▁front ▁feet , ▁making ▁them ▁con ca ve . ▁The ▁only ▁cla w ▁visible ▁in ▁most ▁sau rop ods ▁was ▁the ▁distinct ive ▁thumb ▁cla w ▁( associ ated ▁with ▁digit ▁I ). ▁Al most ▁all ▁sau rop ods ▁had ▁such ▁a ▁cla w , ▁though ▁what ▁purpose ▁it ▁served ▁is ▁unknown . ▁The ▁cla w ▁was ▁largest ▁( as ▁well ▁as ▁tall ▁and ▁later ally ▁fl atten ed ) ▁in ▁di pl od oc ids , ▁and ▁very ▁small ▁in ▁bra ch ios aur ids , ▁some ▁of ▁which ▁seem ▁to ▁have ▁lost ▁the ▁cla w ▁entirely ▁based ▁on ▁track way ▁evidence . ▁ ▁T itan osa urs ▁may ▁have ▁lost ▁the ▁thumb ▁cla w ▁completely ▁( with ▁the ▁exception ▁of ▁early ▁forms , ▁such ▁as ▁Jan ensch ia ). ▁T itan osa urs ▁were ▁most ▁unusual ▁among ▁sau rop ods , ▁as ▁in ▁addition ▁to ▁the ▁external ▁cla w