▁R . ▁Long rich ▁in ▁ 2 0 1 0 ▁and ▁the ▁type ▁species ▁is ▁M oj oc er at ops ▁per if ania . ▁The ▁generic ▁name ▁is ▁derived ▁from ▁mo jo ▁and ▁the ▁specific ▁name ▁means ▁" con sp ic uous ▁pride " ▁in ▁Greek , ▁both ▁referring ▁to ▁the ▁sk ull ▁fr ill . ▁The ▁species ▁is ▁based ▁on ▁foss ils ▁thought ▁by ▁other ▁research ers ▁to ▁belong ▁to ▁Ch asm osa urus . ▁ ▁Classification ▁▁ ▁The ▁species ▁Ch asm osa urus ▁k ais eni , ▁known ▁from ▁spec imen ▁AM N H ▁ 5 4 0 1 , ▁a ▁nearly ▁complete ▁( but ▁partially ▁restored ) ▁sk ull ▁on ▁display ▁at ▁the ▁American ▁Museum ▁of ▁Natural ▁History , ▁was ▁considered ▁to ▁share ▁features ▁in ▁common ▁with ▁M oj oc er at ops ▁per if ania ▁and ▁therefore ▁was ▁considered ▁a ▁possible ▁syn onym . ▁However , ▁the ▁par iet al ▁( back ▁margin ▁of ▁the ▁fr ill ) ▁is ▁not ▁preserved , ▁and ▁was ▁restored ▁with ▁pl aster ▁based ▁on ▁spec im ens ▁of ▁Ch asm osa urus , ▁which ▁caused ▁confusion ▁among ▁scient ists ▁in ▁previous ▁dec ades , ▁because ▁the ▁par iet al ▁b one ▁is ▁critical ▁for ▁determ ining ▁differences ▁between ▁species ▁in ▁cer at ops ids ▁like ▁Ch asm osa urus ▁and ▁M oj oc er at ops . ▁Ch asm osa urus ▁k ais eni ▁was ▁then ▁by ▁Long rich ▁regarded ▁as ▁a ▁nom en ▁dub ium , ▁rather ▁than ▁as ▁the ▁senior