My son recently had a dinosaur party. One activity was "Digging for Dinosaur Bones" in which I used bone-shaped dog biscuits and buried them in our sandbox.
For each one that the children found, they could exchange it for a prize. We also made "Fossils" by making hand or footprints in plaster of paris. The food included a volcano cake and bone-shaped sugar cookies. Also, we made "caveman bites" which were small hors d'oeuvres. We also had a dinosaur-shaped pinata. The children and the adults had a great time!