Make a big bowl of some kind of leaves. Kale would look good and be easy to get. You could stitch it together with some flexible twigs and then fill if with berries and interesting odd fruits for a hunter-gatherer contribution. Then dress like Raquel Welch in One Million Years BC.

Interestingly enough, another web site I frequent featured a link to "the history cookbook," a British site geared towards kids. It features a lot of recipes for historic food, grouped into historic eras; and one of those eras is indeed "Prehistoric".

http://cookit.e2bn.org/historycookbook/index-29-prehistoric.html

One of the recipes they have is for "boar, scallop, and mushroom kebabs," which frankly sounds delicious.

I read the full post after my post, but I do recommend taking the theme over the top for the most fun. Go full out caveman with fur togas, wild hair, and a fire, some drumming and dancing and have some nice clean mud that people can smear on, speak in grunts, squeals and gestures. This kind of party once happened spontaneously after a dip in a pond and it was a hilarious memorable time. We didn't have a fire, drums or food.

I love the salad that Philip and Leona make in the recommended post above - massaged spinach with avocado and blueberries? Delicious. I'm also a big fan of grilled portobello caps.

Check out Mark's Daily Apple for some great paleo recipes: http://www.marksdailyapple.com/

I'm trying to incorporate some aspects of the paleo lifestyle into my diet and I've been learning from the community there.

go to www.marksdailyapple.com for recipes. The entire site is based around a 'paleo' diet.

Another good recipe site is www.everydaypaleo.com

I recently started posting paleo recipes on my blog. Scroll down the recipe index to the Paleo section...
http://impeccabletasty.blogspot.com/p/recipe-index.html

I have a hard time taking themed parties seriously - while I think everyone should participate, I don't think you should have to follow what caveman would eat literally. I would totally make something that looked like a dinosaur. Cookies would be easiest (but not follow the rules), or you could use the approved-of ingredients to concoct a dinosaur.

Oh! Forgot to mention there is a "tastespotting" type website too - photos and links to healthy recipes with a large emphasis on Paleo recipes...

www.chowstalker.com

I third
http://marksdailyapple.com
changed my/many's life.

I love reading http://nomnompaleo.com/. She is a foodie who posts nearly everyday about what she eats along with her recipes.

Guacamole

Paleo diet is easy peasy. Y'all are over thinking it.

I think I might have to drag my girlfriend to a party like that!

Something raw. Preferably the entire leg of a large quadruped.

These Guacamole style deviled eggs seem like they would be easy and quite tasty. http://mypaleokitchen.blogspot.com/2010/01/recipe-review-fat-guacamole-devils.html

The Food Lovers' Primal Palate is an excellent site.
(Also, side note-- paleo represent! this was my first day, so maybe I'll take it showing up on Kitchn as a good sign.)

Kale Chips, Spiced Nuts (almonds, cashews, macadamia nuts, walnuts, not peanuts), Babaganoush, any sort of fresh veggies, roasted red peppers, shrimp cocktail, deviled eggs for appetizers...

Ratatouille makes a great paleo side dish, roasted brussel sprouts (bonus points if it has bacon...), roasted cauliflower with curry (they go surprisingly well together).

Dessert, berries with coconut cream, or coconut macaroons made without flour or sugar.

Hope you have fun at the party!

Giant turkey drumsticks! Like the kind you find at town fairs. Or just massive hunks of meat on sticks :P

Massive beef ribs sound just about right to me!

I think some of you are missing the point, or maybe I am. But I don't think this is necessarily a theme dinner, paleo eating is a lifestyle choice (an extremely healthy one at that) and I'm guessing they just want people to keep the food kosher to paleo standards, which is basically no sugars, no grains, no man made processed foods.

How is this diet healthy? Beef and pork are NOT healthy! I think I would take a bowl of whole grains and veggies over bacon any day!