Rebecca, I'm guessing you are familiar with The Oriental Trading Company? If not, this is a website / catalogue where you can order party favors and decorations for almost any theme at very low cost.
I didn't scour the site, but did notice they have craft kits you can buy, like "Dinosaur Necklace / Nametage Craft Kit" -- $5.95 for a dozen! I liked this one because the girls can make necklaces while the boy guest (or a non-girly-girl) can opt to make his/hers into a nametage, or whatever. And, if you want to make the project more "girly" you could provide glitter, ribbons, beads as an option to jazz it up.
There are probably other ways you can adapt a dinosaur theme...this is completely off the top of my head, so not very brilliant (I'm sure you can do better, but maybe this will trigger some ideas at least...)
You can call it a "Dinosaur Tea Party" or "Dinosaur Dance Party". For the dance party, you could let the children dress up in "dance clothes", tutus and so forth. Games could include a dino-themed version of musical chairs -- I'd call it "Extinction" or something...you could also cut out "dinosaur footprints" in different colors, tape them to the floor and create a game like T-Rex Twister -- or you could number the dino footprints and create a "dance" where the kids have to hop on certain numbers as you call them out...
again, just off the top of my head...but best luck with the party!