1 5 ▁spec ulated ▁that ▁the ▁size ▁estimates ▁of ▁A . ▁frag ill im us ▁may ▁have ▁been ▁highly ▁ex agger ated . ▁The ▁longest ▁din osa ur ▁known ▁from ▁reasonable ▁foss ils ▁material ▁is ▁probably ▁Argent in osa urus ▁hu in cul ensis ▁with ▁length ▁estimates ▁of ▁ ▁to ▁. ▁ ▁The ▁longest ▁terrest rial ▁animal ▁alive ▁today , ▁the ▁ret ic ulated ▁python , ▁only ▁reaches ▁lengths ▁of ▁. ▁ ▁O thers , ▁like ▁the ▁bra ch ios aur ids , ▁were ▁extremely ▁tall , ▁with ▁high ▁shoulders ▁and ▁extremely ▁long ▁ne cks . ▁Sau rop ose id on ▁was ▁probably ▁the ▁tall est , ▁reaching ▁about ▁ 1 8   met res ▁( 6 0   ft ) ▁high , ▁with ▁the ▁previous ▁record ▁for ▁longest ▁neck ▁being ▁held ▁by ▁M amen ch is aur us . ▁By ▁comparison , ▁the ▁g ira ffe , ▁the ▁tall est ▁of ▁all ▁living ▁land ▁animals , ▁is ▁only ▁ 4 . 8 ▁to ▁ 5 . 5   met res ▁( 1 6 ▁to ▁ 1 8   ft ) ▁tall . ▁ ▁The ▁best ▁evidence ▁indicates ▁that ▁the ▁most ▁massive ▁were ▁Argent in osa urus ▁( 1 2 0 ▁metric ▁tons ), ▁Pu ert as aur us ▁( 8 0 ▁to ▁ 1 0 0   metric ▁tons ▁), ▁Al am osa urus , ▁Par al it itan , ▁Ant arct osa urus ▁( 6 9 ▁metric ▁tons ). ▁There ▁was ▁poor ▁( and ▁now ▁missing ) ▁evidence ▁that ▁so -