Most creatures will lose some taming effectiveness during taming, so some creatures have a lower maximum possible post tame level. Finally through breeding you can get creatures who are well above and beyond that number (the maximum level of any Dino on official servers has been capped at 450 as of July 2017).. 450 is the max level a creature can get through breeding and getting mutations (1 mutation = +2lvl) + experience lvl (88 lvl max to win per dino wild or breeded). but there are exceptions like X or R-dinos who can get up to 500.
This is an easy step by step guide to fully control what level wild dinos spawn on your Ark :) If you're having problem finding high level dinos or for some unknown Wildcard-y reason on official servers dinos spawn at random levels like lvl33, lvl28, lvl126, lvl150, you should probably fix that with this simple ini settings guide.. Finally through breeding you can get creatures who are well above and beyond that number (the maximum level of any Dino on official servers has been capped at 450).