Int osh ▁and ▁B erman , ▁the ▁first ▁true ▁sk ull ▁of ▁A pat osa urus ▁was ▁mounted ▁on ▁a ▁ske leton ▁in ▁a ▁museum , ▁that ▁of ▁the ▁Car neg ie . ▁In ▁ 1 9 9 8 ▁it ▁was ▁suggested ▁that ▁the ▁Fel ch ▁Qu ar ry ▁sk ull ▁that ▁Marsh ▁had ▁included ▁in ▁his ▁ 1 8 9 6 ▁ske let al ▁rest oration ▁instead ▁belonged ▁to ▁Bra ch ios aur us . ▁In ▁ 2 0 1 1 ▁the ▁first ▁spec imen ▁of ▁A pat osa urus ▁where ▁a ▁sk ull ▁was ▁found ▁art ic ulated ▁with ▁its ▁cer v ical ▁verte bra e ▁was ▁described . ▁This ▁spec imen , ▁C MC VP 7 1 8 0 , ▁was ▁found ▁to ▁differ ▁in ▁both ▁sk ull ▁and ▁neck ▁features ▁from ▁A . lou is ae , ▁but ▁shared ▁many ▁features ▁of ▁the ▁cer v ical ▁verte bra e ▁with ▁A . ajax . ▁Another ▁well - pres erved ▁sk ull ▁is ▁Br igh am ▁Young ▁University ▁spec imen ▁ 1 7 0 9 6 , ▁a ▁well - pres erved ▁sk ull ▁and ▁ske leton , ▁with ▁a ▁preserved ▁bra inc ase . ▁The ▁spec imen ▁was ▁found ▁in ▁C act us ▁Park ▁Qu ar ry ▁in ▁western ▁Colorado . ▁ ▁Al most ▁all ▁modern ▁pale ont olog ists ▁agreed ▁with ▁R ig gs ▁that ▁the ▁two ▁din osa urs ▁should ▁be ▁class ified ▁together ▁in ▁a ▁single ▁genus . ▁According ▁to ▁the ▁rules ▁of ▁the ▁IC Z