▁latter ▁three ▁tax a ▁an ▁en closed ▁f ossa ▁on ▁the ▁inside ▁edge ▁of ▁the ▁pub is ▁near ▁the ▁ac et ab ular ▁rim , ▁a ▁trait ▁which ▁may ▁be ▁di agnostic ▁to ▁ca en agn ath ids ▁( in ▁which ▁case ▁Nom ing ia ▁is ▁a ▁ca en agn ath id ). ▁O jor apt ors aur us ' s ▁f ossa ▁is ▁further ▁away ▁from ▁the ▁ac et ab ular ▁rim ▁than ▁those ▁of ▁the ▁other ▁species , ▁a ▁feature ▁characteristic ▁to ▁the ▁genus . ▁Among ▁compared ▁o vi ra pt or osa uri ans , ▁O jor apt ors aur us ▁is ▁most ▁similar ▁to ▁Ep ich iro sten otes , ▁a ▁genus ▁differenti ated ▁from ▁Ch iro sten otes ▁in ▁the ▁same ▁paper ▁that ▁O jor apt ors arus ▁was ▁described ▁in . ▁By ▁comparing ▁pub ic ▁proport ions ▁with ▁those ▁of ▁C M ▁ 7 8 0 0 1 ▁( An zu ), ▁O jor apt ors aur us ▁has ▁been ▁estimated ▁to ▁have ▁been ▁about ▁ 1 . 8 ▁to ▁ 2 . 1 ▁meters ▁( 5 . 9 ▁to ▁ 6 . 9 ▁feet ) ▁in ▁length , ▁about ▁ 2 0 % ▁smaller ▁than ▁Ep ich iro sten otes . ▁ ▁O jor apt ors aur us ▁diff ers ▁from ▁other ▁ca en agn ath ids ▁due ▁to ▁possess ing ▁the ▁following ▁aut ap omorph ies : ▁ ▁A ▁“ sp oon - sh aped ” ▁de pression ▁on ▁the ▁anterior ▁d ors al ▁surface