uch us ▁is ▁more ▁than ▁one ▁meter ▁long ▁from ▁the ▁tip ▁of ▁the ▁sk ull ▁to ▁the ▁base ▁of ▁the ▁tail . ▁It ▁was ▁preserved ▁lying ▁on ▁its ▁side , ▁in ▁the ▁same ▁death ▁pose ▁of ▁other ▁b aur us uch ids ▁collected ▁in ▁the ▁site . ▁L PR P / US P ▁ 0 2 2 9 a , ▁preserved ▁in ▁two ▁different ▁blocks , ▁suffered ▁some ▁post - mort em ▁dis art ic ulation , ▁and ▁as ▁a ▁result ▁most ▁of ▁the ▁tail ▁and ▁the ▁dist al ▁parts ▁of ▁the ▁h ind lim bs ▁were ▁lost . ▁A pl est os uch us , ▁like ▁other ▁b aur us uch ids , ▁was ▁a ▁fully ▁terrest rial ▁pred ator . ▁Re aching ▁up ▁to ▁four ▁meters ▁in ▁length , ▁b aur us uch ids ▁were ▁the ▁a pe x ▁pred ators ▁of ▁the ▁South ▁American ▁Late ▁C ret ace ous ▁e cos ystem s . ▁They ▁were ▁sur pass ed ▁only ▁by ▁large ▁ther op ods , ▁however , ▁these ▁are ▁very ▁rare ▁in ▁the ▁Adam ant ina ▁Form ation ▁and ▁represented ▁by ▁isolated ▁and ▁fragment ary ▁teeth ▁mostly ▁attributed ▁to ▁ab el is aur ids ▁and ▁c arch arod ont osa ur ids , ▁and ▁isolated ▁meg ar apt or id ▁and ▁un en lag i ine ▁verte bra e . ▁The ▁s ph ages aur id ▁material ▁recovered ▁in ▁the ▁ab dom inal ▁cav ity ▁of ▁A pl est os uch us ▁was ▁considered ▁more ▁likely ▁derived ▁from ▁pred