Guess Which Dino
Write down the names of different types of dinosaurs on separate index cards so that you have enough cards for every child. Before you start, point out the differences between each dinosaur you have written down. Tape an index card bearing a dinosaur name to each child's forehead so he cannot see his own card. The children then start to ask each other yes-or-no questions to determine which dinosaur they have on their heads. Questions include "Do I eat other dinosaurs?" or "Can I fly?" Play until all of the children have guessed their dinosaurs.
Hatch the Dino Egg
Blow up several balloons in the shape of an egg. Dig out a little nesting spot in a sand castle or in the dirt so you can nestle your balloon eggs on them. Once you have a line of about five balloon eggs, pick one player to start the game. He stands about 10 feet from the first egg. When you say "Go," he has to race to "hatch" all of the eggs by sitting on them, starting with the first egg and ending with the last. As he does this, time him.
Replenish the balloons and let all the kids have turns. The player with the fastest time wins.
Tyrannical Tyrannosaurus
Pick one child out of the group to play a Tyrannosaurus rex. She counts down from 30 while all the other players run away to find hiding spots. Once she has finished counting, she races around roaring and attempts to tag as many players as possible. Once a player is tagged, he has to freeze in place. If another player crawls under his legs, he can move again. The T-rex continues tagging players until she has frozen all the players; at which point, you can select a new T-rex.
Dinosaur Scavenger Hunt
Cut out several dinosaur footprints from green construction paper. Hide three or four chests of prizes around the play space, and lead the footprints from a common starting point to the treasure chests. Use the footprints to make other paths that lead to nothing. Gather up all the players in at the starting point and tell them that dinosaurs have left footprints leading to ancient treasures. When you say "Go," all the players race to follow the tracks. After they find the chests, separate the bounty among the kids equally.