Simply do the following to pass the stage with the golden crown.

Put the first animal between the lizard and mammoth
Place the second animal between the mammoth and caveman.

Stage one: Dinosaur, Monkey
Stage two : Pterodactyl, Chimp
Stage three : Stegosaurus, Monkey

Scribblenauts Remix 1-9 Cheats Hints gallery:
1-9-1-a: Complete the missing links!
1-9-1-b: This is an evolutionary ladder.
1-9-1-c: What were the mightiest reptiles? What is the caveman’s closest ancestor?