the Mesozoic era

a dinosaur (animal of the clade Dinosauria)

rule, control, command / direction, management, governance / dominance

to rule, to control, to command / to direct, to manage, to govern / to dominate

age, era, period (of time) / the times, spirit of the age / antiquity / a time in one's life, one's days (in college etc.)

ruler (one who governs)

ruling; governing; prevailing; controlling; predominant; as, the dominant party, church, spirit, power

(politics) gerontocracy

anachronism

youth (part of life following childhood)