After the beast was killed, Adam saw his EXP rise by 13 points, instead of the 3 points that it would have been if he didn't upgrade his Dungeon Form to LVL 2, and also saw something enter his inventory.
Adam didn't need to physically loot the beasts after defeating them, which was a handy feature of the system, and the loot would automatically enter his inventory after the beast disintegrated, if there was any, unlike how it was on Floor 0 where Adam had to physically gather the loot.
{Would you like to collect this beast as your Primate base beast. YES / NO}
[Yes] answered Adam without hesitation.
He felt the Forest Monkey that he just defeated enter the beastpedia that was within his mind and was also notified that it had entered his beastpedia through his menu.