▁of ▁Sant onian ▁le pt oc er at ops id . ▁It ▁was ▁named ▁based ▁on ▁a ▁partial ▁left ▁dent ary ▁from ▁Al berta , ▁Canada . ▁G ry ph oc er at ops '' ▁represents ▁the ▁oldest ▁known ▁le pt oc er at ops id ▁and ▁probably ▁the ▁smallest ▁adult - s ized ▁cer at ops ian ▁known ▁from ▁North ▁America . ▁ ▁Le pt oc er at ops ids ▁are ▁known ▁from ▁Eastern ▁North ▁America ▁by ▁a ▁partial ▁max illa ▁dated ▁to ▁the ▁early ▁Camp an ian ▁of ▁North ▁Carolina , ▁whilst ▁the ▁European ▁material ▁referred ▁to ▁Le pt oc er at ops idae ▁consists ▁of ▁isolated ▁teeth ▁and ▁verte bra e ▁from ▁the ▁early ▁Camp an ian ▁of ▁Sweden . ▁The ▁former ▁represents ▁the ▁first ▁known ▁cer at ops ian ▁from ▁Eastern ▁North ▁America , ▁and ▁its ▁special ised ▁max ill ary ▁an atom y ▁supports ▁the ▁hypothesis ▁that ▁App al ach ia ▁was ▁isolated ▁from ▁Western ▁Europe ▁and ▁Lar am idia ▁for ▁an ▁extended ▁period ▁during ▁the ▁Late ▁C ret ace ous , ▁resulting ▁in ▁an ▁en demic ▁Late ▁C ret ace ous ▁fa una . ▁The ▁shared ▁presence ▁of ▁le pt oc er at ops ids ▁in ▁App al ach ia ▁and ▁Western ▁Europe ▁has ▁imp lications ▁for ▁their ▁bi oge ographic ▁dispers al , ▁suggesting ▁the ▁possibility ▁that ▁le pt oc er at ops ids ▁entered ▁App al ach ia ▁through ▁either ▁Western ▁Europe ▁or ▁Lar am idia ; ▁however , ▁it ▁is ▁also ▁possible ▁that ▁the